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Purveyors of Electronic, Musical and Vintage goods from then, now and in between. 
Since 1982.

FULLY SERVICED / WARRANTED
STEREO PRE-AMPS, POWER AMPS,
 INTEGRATED AMPLIFIERS
USED, VINTAGE & CLASSICS FOR SALE

 

Stereo amps amplifiers & Pre-amps: Classic / pre-owned, Vintage stereo control / preamps, integrated amps & power amplifiers by Dynaco, Pioneer SA, SAE Mark, Sansui AU, Hafler, Kenwood KA, KC, KM Marantz PM, Onkyo, Technics SU / SUV, Sony, JVC, Harman Kardon HK for sale.

 


OUR SERVICED / RESTORED AMPS, PRE-AMPS, POWER AMPS AND INTEGRATED AMPS:
 
 
  
 



    




          NEW LISTING 1/8/19
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED & WARRANTED 
VINTAGE MITSUBISHI STEREO INTEGRATED AMPLIFIER / AM/FM TUNER
MITSUBISHI DA-C20
DUAL MONO CONSTRUCTION

 #...0324
Circa 1978-'80

MIJ
for sale
DC-C20, DA-M10 & DA-A10DC
(see listing to the right for details on the 'Power Amp / Meter bridge')


 
ü  Our technician has completely gone through and 'Certified' this unit.

ü Following ext / int visual inspection entire unit was cleaned inside and out including all contacts, switches and controls (VERY difficult to access. Requires complete tear down to clean controls properly).



ü Meters calibrated per service manual.

ü Switches and controls now clean sounding and performing solidly.

 
ü All functions tested for perfect operation.

ü All inputs tested and both side produces clean and even sine waves!

ü No power supply hum of any kind. It's dead silent!

ü Following electronic refurb, entire unit was cosmetically detailed (as it 'practically' allowed).

ü We also aligned the tuner front-end on both AM & FM bands for optimum performance as older tuner components will have 'drifted' over the years.

ü AM 'Stick' ferrite core adjusted for optimum reception and minimal noise

ü AM 'Stick' antenna 'ball and socket' inspected and is holding well.

ü Tuner string checked for any fraying then re-tensioned to increase traction & relieve flywheel binding and re-centered pointer to correct dial position.

ü VERY GOOD TUNER! Generally AM reception in a stereo receiver is treated as an 'after thought', but the AM reception on this one is WAY above average. Pulls in stations like an old 'Tube' radio! FM reception also incredible and IMPECCABLY CLEAN!!!

ü Following service / refurb procedures, the unit was ran continuously at medium volume, as all our amplifier / receivers are, into a 4 Ohm load with "Loudness" on and both Tone Controls at 10 for 48 hours.
Total restoration time investment
11+ hours. You will not be disappointed.

 
Very classy 'Pewter / Silver' face Mitsubishi Pre-Amp / Tuner. VERY impressive in stature and cosmetics. Looks great with matching Meter Bridge attached to Mitsubishi power amp. Cosmetically it's in BEAUTIFUL condition with only items worth mentioning would be some light finish scuffing on one end from being set on it's side (not visible from front of unit) and the word "Power" missing all but the "P" from the silk screening above power switch (see photos above).


Mitsubishi DC-C20 AM/FM Tuner / Pre-Amp Features and 'Creature Comforts' include:


-True Dual Channels w/ separate L & R Tone / Output levels
- Delay power On / Power Off sequencing when connected to power amplifier
- Speaker selector for A or B, A+B or Off (when connected to amplifier via proper umbilical cord)
- Subsonic filter with 18Hz cut-off built-in for cutting turntable rumble
- Super quality de-tented Attenuator (volume) control
- Separate L & R Tone Defeat for purest tone path if so desired
- Separate L & R Bass and Treble with high quality de-tented controls
- Pre-amp section 'Stereo / Mono' / Reverse Stereo selector
- Dual tape deck monitors (Tape Monitors can be used with Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Bi-Directional Tape Duplication
- Dual Phono / Turntable inputs w/ 'Built-in' phono pre-amp for MM or MC
- Tuner input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRUS® etc.)
- AUX input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRUS®, audio mixers, computer sound-cards etc.)
- Analog / D'arsonval Signal Strength meter
- Analog / D'arsonval Center Tune meter
- Wide / Narrow Band selector for Tuner
- Tuner 'Lock' for drift-free reception
- FM Mute / Stereo / Mono selector
- Vertical and Horizontal Multi-path RCA outputs
- Front mounted 1/4" stereo headphone jack
- Side panel features full RCA patch bay for all inputs (each 'fastened separately' to the rear panel, and 'point to point' wired internally, instead of being soldered directly to the circuit board, which is always a 'failure point').
- 3-Pin connector for amplifier umbilical speaker connectors for A&B speakers

-
2 Switched and 1 un-switched AC outlets for a maximum load of 900 Watts of external gear.

 
Mitsubishi DC-C20 AM/FM Tuner / Pre-Amp Original Specifications:

TUNER SPECS:
Tuning Capacitor:
5-
gang
Tuning Range:
88-108MHz
Freq Response: 30-15kHz (FCC Limits)
Useable Sensitivity: Mono 11.2 dBf / 2.0 μV
Stereo 22.7 dBf / 7.5 μV
50dB Quieting Sensitivity: Mono 19.2 dBf / 5.0 μV
Stereo 39.2 dBf / 50 μV
S/N @ 65dBf: >80db Mono or 75dB Stereo
Capture Ratio @ 65dBf (Wide / Narrow): 0.8 dB / 1.5 dB
THD Mono @ 1kHz: 0.05% (Wide)
THD Stereo @ 1kHz: 0.08% (Wide)
FM Alternate Channel Selectivity (Wide / Narrow): 45dB / 75dB
Spurious Noise Ratio: 90dB
IF Response Ratio: 80dB
AM Suppression: (Wide / Narrow): 55dB / 50dB
Stereo Separation (Wide / Narrow): 45dB @ 1k & 35dB @ 10kHz / 40dB @ 1k & 30dB @ 10kHz
Subcarrier Product Product Ratio: 70dB
Image Response Ratio: 80dB
Antenna Impedance: 75 or 300 Ohms

TUNER SPECS FOR AM (IHF):
Tuning Range: AM Band 525 kHz-1605 kHz
S/N: 
>50db
Useable Sensitivity (IHF Bar Antenna): 45 dB
Selectivity: 30dB @ 1kHz
Hum & Noise: 50dB
THD: 0.8%
IF Response Ratio: 70dB
Image Response Ratio: 40dB


PRE-AMP SPECS:
S/N (IHF): 110dB for 'non-phono' inputs
THD: 0.003%
across 20-20kHz @ rated attenuator output of -20dB
Freq Response (non-phono inputs): 10Hz-100kHz at full rated power
Input Sensitivities 'non-phono' inputs for full rated output:
150mV / 50kΩ via RCA's
Output at Main Output: 1V for 'rated output' @ 600 Ohms
Output at Tape Monitors: 150mV / 600 Ohms via RCA's
Bass Control:  ±10dB @ 100Hz
Treble Control:  ±10dB @ 10kHz
Subsonic Filter:  -6dB / oct @ 18Hz

Output at Headphones: 600mV
(at output of 1V) / 15 Ohms. 650mV max.
 
Phono Section:

Freq Response: 20Hz-20kHz RIAA EQ
S/N: MM= 84dB (Shorted)
MC= 77dB (terminated w/ 47 Ohms)
Phono THD: MM= 0.003% @ 20-20kHz
MC= 0.005% @ 20-20kHz
Phono MM Sensitivity: 2.5mV / 50k Ohms / 10pF
Phono MC Sensitivity: 0.1mV / 10 Ohms
Phono Maximum Input Level: MM= 290mV RMS while still maintaining 0.1% THD @ 1kHz
MC= 12mV RMS while still maintaining 0.1% THD @ 1kHz

 
Again, as stated before, our technician has completely refurb'd this
Mitsubishi DC-C20 AM/FM Tuner / Pre-Amp
, cleaning and testing all and it gets our full 'Certification'. Entire unit, including the original brushed aluminum, Face and knobs are in beautiful condition. Unit looks beautiful and sounds great. This is the first 'complete combo' of these components we've had.
Comes with an 'e' copy / pdf download of the original Mitsubishi DC-C20 AM/FM Tuner / Pre-Amp users manual and service manual if purchaser so desires. Also includes the original 3-pin, umbilical speaker control cable for connecting the power amp to the speaker selection section of the pre-amp.

Measures 16.75" wide x 11.5" deep x 6.75" tall and weighs 19 lbs unpacked.
Total weight of all three components is 65 lbs. Includes our 90 day limited warranty!
Mitsubishi DC-C20 AM/FM Tuner / Pre-Amp

Cond. 8.5+++
$1499. for all three components
DC-C20, DA-M10 & DA-A10DC
(see listing to the right for details on the 'Power Amp / Meter bridge')


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)


 



    
    



          NEW LISTING 1/8/19
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED & WARRANTED 
VINTAGE MITSUBISHI POWER AMPLIFIER
MITSUBISHI DA-A10DC STEREO POWER AMP
WITH ORIGINALLY OPTIONAL MITSUBISHI DA-M10 METER BRIDGE
TRUE DUAL POWER SUPPLIES
 ONE OWNER!
MIJ
for sale

DC-C20, DA-M10 & DA-A10DC
(see listing to the left for details on the 'Pre-amp / Tuner')


ü Our technician has completely gone through and 'Certified' this unit.

ü Much of amplifier disassembled, the everything cleaned inside and out including all switches, controls and contacts. Cleaned and re-lubed all control shafts.



ü Internal fuses checked for correct value / function and replaced where necessary.



ü Solder joints reflowed on all possible high heat and stress points

ü Amplifier section had output bias and DC offset adjusted to spec levels after 10 min warm-up.



ü Meter Lamps replaced with correct bulbs (8V / 200mA)



ü Analog, VU / D'Arsonval Meters adjusted 'mechanically' for 'Zero' position, and electronically to match amp output.

ü All functions tested for perfect operation.

ü Following above procedures, unit was cosmetically detailed inside and out.

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü Following service / refurb procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours.
Total restoration time investment 10.5+ hours. You will not be disappointed.

On our test bench, each internal amplifier of this particular unit, #...0128, produced peak power of 31.5 Volts per channel at 8 ohms for 124 Watts per channel and 27Volts at 4 ohms for 182 Watts per channel via discrete output transistors (2X Sanken 2SA908 & 2SC1585).
AC Idle current at 450mA. Floor noise > -60dBm.
 
____________________________


Performs and sounds fantastic! All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! Following restoration procedures, we burned it in, in the shop for 48 hours and it functioned flawlessly (we actually took it into our 'demo' system and 'rocked-it' HARD on our Altec VOTT's. HUGE sound and thump).

This is a Huge and Beautiful looking, performing and sounding power amplifier. Great 'High-Tech' look (in 'vintage terms anyway). Cosmetically, it looks great with only a few minor 'dings / scratches', mostly not visible from the front. The minor scratches on the front are faint and fairly 'un-noticeable' (see photos above).
While it could be used with any other pre / control amp, as they came in as a pair from the original owner, we only want them to stay together to their 'new' owner.


Mitsubishi DA-A10DC / DA-M10 Features:

- True DUAL power supplies (has a lot to do with how much this amp 'punches'. (See photos above of power supply)
- Huge, Externally located, 'vertically finned' heat-sinks
- DC protection for 'Turn-On Surge' and 'Output'
- A and / or B speaker selector
- Front mounted 'Gain / Level' controls via the Meter option on the front. Power amp has input levels on the rear panel as well (slotted heads for screw-driver)
- Huge, Beautiful, Lit VU Power Output meters
- Meter Range selector for either normal or 'x 0.1'
- 'Thermal Indicators' located on heat-sinks (think "mood ring" technology)
- Signal inputs via standard RCA jacks
- Three-pin jack for 'Mitsubishi' connector cord to Mitsubishi Pre-amp speaker switch controller


Mitsubishi DA-A10DC Specifications:

Rated RMS Output: 100 Continuous Watts per channel, min. RMS, @ 8Ω, both channels driven, from 15Hz to 30kHz.
Power Bandwidth:
10Hz to 100kHz @ 8Ω, both channels driven
Signal to Noise Ratio: 107dB un-weighted (closed input), 122dB (20Hz to 20kHz) at full RMS output (closed input)
Total Harmonic Distortion (THD): <0.01% @ rated output, <0.005% @ half output
IMD: 0.008% @ rate
d power / 8Ω
Slew Rate:
30V/μsec @ 8 Ohms / 50V P-P
Damping Factor: 100 @ 8 Ohms / 20Hz to 20kH
Load Impedance: Rated for 16, 8 or 4
Ohm use
Input Impedance: 50k Ω nominal
Input Sensitivity: 1V for rated power into 8Ω
Channel Separation: 1
00 dB @ 1kHz and 80dB @ 20kHz
Input Connector: Standard RCA jacks

Again, as stated before, we have completely gone through this
Mitsubishi DA-A10DC
, Power Amplifier cleaning and testing all and it gets our full 'Certification'. This is an amazing performing and sounding amp. We have 'stood on it' hard, with a number of our speaker loads (the most fun being when connected to our Altec 'Voice of the Theaters'. It's a huge sounding and punchy amp, with lots of 'head room'. Handles 'REAL' high power levels perfectly well. If you are looking for serious, vintage power, it ain't gonna get much better than this.
Also includes the original 3-pin, umbilical speaker control cable for connecting the power amp to the speaker selection section of the pre-amp.

 Comes with an e-copy, pdf download, of the
Mitsubishi DA-A10DC Owners Manual and Service Manual.
Measures standard 17" wide x 15" depth x 6.75" tall and weighs 46 lbs unpacked. Total weight of all three components is 65 lbs. Includes our standard 90 day limited warranty.
Mitsubishi DA-A10DC Power Amplifier / DA-M10 Meter / Control panel.
 Cond. 8.5
+
$1499. for all three components
DC-C20, DA-M10 & DA-A10DC
(see listing to the left for details on the 'Pre-amp / Tuner')

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)


 


PRE-AMPS:
 

    

   NEW ADDITION 8/20/19
 (Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
FULLY SERVICED WITH WARRANTY
VINTAGE TUBE CLASSIC!
DYNACO / DYNAKIT PRE-AMP / CONTROL AMPLIFIER
DYNAKIT PAS-2

#...6855
Circa 1964-69
FACTORY BUILT VERSION
MADE IN AMERICA
for sale

ü Two technicians have completely gone through this unit. First an 'old-school, outside' shop, versed in tubes prior to it reaching us, then by our senior tech. The procedures outlined below will be spread between the two shops.


ü We have completely gone through this unit, cleaning inside and out including all contacts, switches and controls.

ü Power transformer replaced

ü All existing tubes tested fine (4x German Dynaco / Telefunken 12AX7 & 1x USA Tungsol 6X4 Rectifier tube)

ü New Electrolytic Filter capacitors

ü Selenium rectifier replaced with Silicone Diodes at some point in it's past (always preferable)

ü 12X4 replaced with 6X4 at some point in it's past (common mod)

ü Other various resistors and capacitors replace per previous service work

ü New #1893 Pilot lamp installed which taller than original, thus increasing brightness of Orange jewell

ü Unit All RCA I/O jack terminal solder joints re-flowed internally

ü Unit cosmetically detailed, but does have a few scratches on the metal case /cover and various 'marks / stains' to the brass face panel (see photos above)

ü 
All functions tested for perfect operation.

ü All inputs tested fine following I/O re-flow operation

ü Both sides produce clean and even sine waves!

ü No power supply hum of any kind. It's dead silent! 
  ____________________________

  
Classic, Tube Pre-Amp. These have been a 'Vintage Hi-Fi Mainstay' for decades. Great pre to build a system around. GREAT sounding as well. Not a fan of the I/O jack labeling (or lack there-of), but that was an earlier time.

DYNAKIT PAS-2
Features include:
  
- 5-Tube circuitry
- Partial Point to Point wiring design

- Separate L&R Bass and Treble Controls
- Stereo / Mono / BLEND control
- Tape monitors with A>B dubbing
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Spare (AUX / CD)
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Separate AM or FM Mono or FM Stereo inputs
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Phono / Turntable input with Built-In Phono Pre-Amp
- Tape Head Input. This is used for connecting a 'transport only' type, Reel to Reel tape deck
- "Special" input. This is currently somewhere between 'Tape-Head' and 'Phono' level. It is an input that can be internally wired for a number of input configurations, including a second turntable, magnetic or crystal cartridges, microphones or specifically for 78 RPM records or...etc.

- 'Scratch' / Hi-Filter for reducing 'hiss' in AM etc.

- Loudness selector
- 4 AC outlets, All un-switched

Dynakit PAS-2 Original Specs:
  
 
Design type: 2 Channels, Analog operation

Transient Performance; "Pass square waves without ringing and with minimum deformation from 20-20kHz. No 'over-shoot or bounce on 'pulse type' signals. Instantaneous recovery from overload (means great damping factor and fast slew rate)
THD Tuner, AUX and Tape, 20-20,000Hz: 0.05%
@ 1V output
Hum & Noise: "2 microvolt equivalent noise on RIAA. 74dB below level of 10 mV signal."
Bass Control; ±20dB @ 20Hz
Treble Control; ±14dB @ 20kHz

  
This is one of the most famous of the vintage pre-amps. All Tube design, and surprisingly 'quiet'. Rear I/O label faded, so we're including a 'printed sheet' with the I/O labels. Unit looks good, works and sounds great! Measures 13" wide x 4.25" tall x 8.5" deep and weighs 8 lbs unpacked. Includes 30 day limited warranty, not applicable to tubes.
FACTORY BUILT, DYNAKIT PAS-2

Cond. 8
$689.
with originally installed, Four German made, Dynaco / Telefunken 12AX7 tubes!!! (as well as the USA 'Tungsol')

(CONS. R.R.)

 
(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)


 

 

 



    


               NEW LISTING 11/2018
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
SERVICED / REFURBISHED*
KENWOOD STEREO PRE- AMP
KENWOOD CONTROL AMPLIFIER "Basic C2"

#...0478
Circa 1984-90 
for sale

ü Our technician has completely gone through this unit*.

ü We have completely gone through this unit, cleaning inside and out including all contacts, switches and controls.



ü Unit originally presented with one channel down. As we've had a number of these, we knew that it was likely the "Balance" control potentiometer. It was the issue, so the pot was 'jumpered'*. Fairly 'excusable' work around as most folks are typically leaving their 'balance' control turned to the center 100% of the time anyway.
While this is a fairly versatile pre-amp, that we 'still like', it does have a few 'difficult to service' issues and a couple of 'semi-permanent' defects. Firstly there's a fairly common issue with the 'balance' control pot. It's anemic / fragile in the first place, which makes it prone to 'breaking' in such a way that it will drop channels. We have not found a replacement. There are a couple of websites that have photo essays on doing 'micro-surgery' on them, but it's very difficult, time consuming with sketchy results. Probably the most practical way to address the issue with the balance pot is to 'jumper' across it. It can either be left in place or removed once jumpered.

The same 'fix' can be utilized on the 'Headphone' level pot, then simply use the main volume of the pre-amp to control the headphone level (like EVERY other unit does).
(headphone level control still works on this unit)

ü Unit All RCA I/O jack terminal solder joints re-flowed internally





ü  All inputs tested and both side produces clean and even sine waves!

ü  No power supply hum of any kind. It's dead silent! 

ü  All inputs tested and both side produces clean and even sine waves! Checked with O-Scope.

ü  No power supply hum of any kind. It's dead silent!
  
____________________________
 
 
Versatile Kenwood "Basic C2" Pre-amp / control center. Would match up well with any power amp and is very "utilitarian". Loaded with "real world" features. Again, with the exception of the 'bypassed balance control', the unit works well and sounds great! Cosmetically the only issue really worth mentioning is that the top, metal cover has scratches from someone sitting a unit with no feet on it and moving it around.

Kenwood C2 Features include:
 
 

- Separate Bass and Treble with selectable turnover frequency
- Turnover freqs set at 200 or 400 on the bottom end and 3k or 6kHz on the top end.
- Selector for MM or MC cartridges
- 5 position phono cartridge EQ selector (this feature, combined with the MM/MC selector / head-amp alone can be worth a few hundred dollars, if you're contemplating moving up to a Moving Coil turntable cartridge. MC carts require an extra head-amp and this amplifier has one built in)
- Built-in Low and Subsonic Filters to eliminate excess rumble from sources such as turntables. These are selectable for either 58Hz, 40Hz or 18Hz @ 18dB / Oct.
- Hi "Scratch" filter set at 8Khz with a slope of 12dB / Oct. Useful for reducing the 19kHz pilot tone in FM and tape hiss / electronic hiss & noise and record static
- Output defeat
- Mono / Stereo input selector

- Phono / Turntable input with Built-In Phono Pre-Amp
- Dual Tape Monitors with bi-directional dubbing
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc. as well as for CDR)
- Dual (1 & 2) Aux inputs
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- CD Input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- Headphone output with separate level control
- Indicator LED's for input selector
- 3 AC convenience outlets ( 2 switched 1 un-switched)

  
Kenwood C2 Original Specs:
  
 
Design type: 2 Channels, Analog operation
Frequency Response: 1-350kHz +0 / -3dB
Maximum Output Level: 1V
THD: 0.001% at full rated power
Phono MM Sensitivity: 2.5mV for 5.0V output @ 1kHz
Phono MM Maximum Input Level: 200mV
Phono MC Input Impedance: Selectable
S/N on Phono MM w/ 5mv signal: 94dB
Phono Capacitance: Selectable
High Level Sensitivity (tuner, Aux, Tape): 150mV

  
The Kenwood C2 has always been one of our favorite pre-amps under $606-$800. It's simply hard to beat for specs, features and performance. That is also evidenced by the fact that it was current in Kenwood's lineup, as their upper end pre, for almost half a decade. Again, we have completely gone through the unit cleaning all contacts, pots, switches and controls. All functions (again, with the exception of the 'Balance' control') test as original. Unit looks and sounds great! Unit measures 17.25" wide x 3" tall x 13" deep and weighs 10 lbs unpacked. Comes with original owners manual and includes our 90 day limited warranty.
KENWOOD BASIC C2
Condition 7.5 (due to balance control issue)

$359.

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)



 


 

 

 

    

               NEW LISTING 11/2018
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
SERVICED / REFURBISHED*
KENWOOD STEREO PRE- AMP
KENWOOD CONTROL AMPLIFIER "Basic C2"

#...0258
Circa 1984-90 
for sale
ü Our technician has completely gone through this unit*.

ü We have completely gone through this unit, cleaning inside and out including all contacts, switches and controls.



ü *Unit originally presented with one channel down. As we've had a number of these, we knew that it was likely the "Balance" control potentiometer. It was the issue, so the pot was 'jumpered'*. Fairly 'excusable' work around as most folks are typically leaving their 'balance' control turned to the center 100% of the time anyway.
While this is a fairly versatile pre-amp, that we 'still like', it does have a few 'difficult to service' issues and a couple of 'semi-permanent' defects. Firstly there's a fairly common issue with the 'balance' control pot. It's anemic / fragile in the first place, which makes it prone to 'breaking' in such a way that it will drop channels. We have not found a replacement. There are a couple of websites that have photo essays on doing 'micro-surgery' on them, but it's very difficult, time consuming with sketchy results. Probably the most practical way to address the issue with the balance pot is to 'jumper' across it. It can either be left in place or removed once jumpered.

The same 'fix' can be utilized on the 'Headphone' level pot, then simply use the main volume of the pre-amp to control the headphone level (like EVERY other unit does).


ü Unit All RCA I/O jack terminal solder joints re-flowed internally





ü *Unit also has an issue with the *'Hi-Filter' switch. While it has been cleaned and lubed, it will not 'lock in' so consider there's no 'Hi-Filter' on this one (yes, the circuitry still functions, but was not practical for use to source a replacement switch on this unit with the other two issues. "Hi-Filter" is also a fairly 'fringe' feature and seldom used by most folks, so we decided it was 'excusable')

ü *Unit also has the issue, common with the "Balance" control potentiometer affecting the headphone amplifier, with additional issue with the 'headphone' section, thus we have bypassed the entire headphone functions on this one.

ü All inputs tested and both side produces clean and even sine waves! Checked with O-Scope.

ü  No power supply hum of any kind. It's dead silent! 
  
____________________________
 
 
Versatile Kenwood "Basic C2" Pre-amp / control center. Would match up well with any power amp and is very "utilitarian". Loaded with "real world" features. Again, with the exception of the 'bypassed balance control', the unit works well and sounds great! Cosmetically the only issue really worth mentioning is that the top, metal cover has scratches from someone sitting a unit with no feet on it and moving it around. Also, as the 'Balance' and 'Headphone Level' are 'non-functional', we inserted hole plugs where the knobs would be (the pots are still there if anyone wants to attempt a repair in the future.)

Kenwood C2 Features include:
 
 

- Separate Bass and Treble with selectable turnover frequency
- Turnover freqs set at 200 or 400 on the bottom end and 3k or 6kHz on the top end.
- Selector for MM or MC cartridges
- 5 position phono cartridge EQ selector (this feature, combined with the MM/MC selector / head-amp alone can be worth a few hundred dollars, if you're contemplating moving up to a Moving Coil turntable cartridge. MC carts require an extra head-amp and this amplifier has one built in)
- Built-in Low and Subsonic Filters to eliminate excess rumble from sources such as turntables. These are selectable for either 58Hz, 40Hz or 18Hz @ 18dB / Oct.
- Hi "Scratch" filter set at 8Khz with a slope of 12dB / Oct. Useful for reducing the 19kHz pilot tone in FM and tape hiss / electronic hiss & noise and record static (again, NON-functional on this particular unit, #...0258)
- Output defeat
- Mono / Stereo input selector

- Phono / Turntable input with Built-In Phono Pre-Amp
- Dual Tape Monitors with bi-directional dubbing
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc. as well as for CDR)
- Dual (1 & 2) Aux inputs
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- CD Input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- Headphone output with separate level control (again, NON-functional on this particular unit, #...0258)
- Indicator LED's for input selector
- 3 AC convenience outlets ( 2 switched 1 un-switched)

  
Kenwood C2 Original Specs:
  
 
Design type: 2 Channels, Analog operation
Frequency Response: 1-350kHz +0 / -3dB
Maximum Output Level: 1V
THD: 0.001% at full rated power
Phono MM Sensitivity: 2.5mV for 5.0V output @ 1kHz
Phono MM Maximum Input Level: 200mV
Phono MC Input Impedance: Selectable
S/N on Phono MM w/ 5mv signal: 94dB
Phono Capacitance: Selectable
High Level Sensitivity (tuner, Aux, Tape): 150mV

  
The Kenwood C2 has always been one of our favorite pre-amps under $606-$800. It's simply hard to beat for specs, features and performance. That is also evidenced by the fact that it was current in Kenwood's lineup, as their upper end pre, for almost half a decade. Again, we have completely gone through the unit cleaning all contacts, pots, switches and controls. All functions (again, with the exception of the 'Balance' control') test as original. Unit looks and sounds great! Unit measures 17.25" wide x 3" tall x 13" deep and weighs 10 lbs unpacked. Comes with original owners manual and includes our 90 day limited warranty.
KENWOOD BASIC C2
Condition 7 (due to balance control, headphone amp and Hi-Filter issues)

$299.

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)



 

 


POWER AMPS:
 

      

         NEW
LISTING 6/17/19
 
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED & WARRANTED 
 VINTAGE DYNACO STEREO POWER AMPLIFIER
 DYNACO "STEREO 120" POWER AMP
#...2874
 Circa 1969-78
 MADE IN U.S.A.

for sale

 Our technician has completely gone through and 'Certified' this unit. Output transistor removed and tested independently. Multiple Electrolytic Caps replaced. The balance tested and passed. Unit bench checked / tested. Output transistors 'Beta Matched'. All functions have been tested and pass with flying colors! Both inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent!
This is one of the most 'famous' power amplifiers ever designed and sold. Originally co-designed by David Hafler (always been a favorite amp engineer of mine), they have been the 'heart' of many audio systems since the late '60's.
    

On our test bench, this particular Dynaco Stereo-120, #...2874's amplifiers produced 23 Volts at 8 Ohms per channel for 66Watts / channel and 18 Volts at 6 Ohms per channel for 81 Watts / channel via discrete, metal cased, TO-3 output transistors. (Idle AC current draw @ 0.5A.
DC less <3mVDC / Ch (under 8 Ohm load).
Floor noise measured at L& R = 2.3mVAC) 
    

 Dynaco amps have always been known for understated appearance and performance. While they were never much on looks or 'whistles and bells', they made up for that in performance. Excellent for 2-channel (stereo) audio listening or for use in an A/V system or for driving project studio monitors.
    

- 2-Channel stereo, Class A/B operation
- Standard RCA input jacks
- Oversize power supply transformer and capacitors
- 3-Way, Binding post speaker jacks
- AC / MAINS protection fuse

    
DYNACO STEREO-120 Original Specs:
Design type:
2 Channels, AB operation
Damping Factor @ 20kHz-20kHz / 8Ω: >40
Signal / Noise: >100dB @ 60 Watts
Input Sensitivity: 1.5V for 60 Watts output
Input Impedance: 100k Ohms
Channel Separation: >70dB @ 20Hz-20kHz
Rated RMS Output Stereo: 60 Watts per channel, min. RMS, @ 8Ω
IMD; <0.5% @ rated power / 8Ω
Freq response: 5Hz-100kHz @ 8Ω
Wall AC current needed:
400 Watts
  

Again, our senior tech has completely gone thru this Dynaco Stereo-120 and it gets our full
'Certification'.  Nickel / chrome plating is in great shape with none of the typical surface pitting / corrosion / rust. Perforated, top cover also rust and dent free. Unit looks, works and sounds great! Again, while not much on cosmetics or 'button features / whistles or bells' Dynaco amps are known for incredible punch, headroom, and musicality. Includes an 'e-copy' pdf download of the Dynaco Stereo 120 owners / users / instruction / assembly / service manual (which is actually an 'amazing read' and should probably be read by anyone using / owning ANY amplifier from ANY brand and ANY model! Just FYI).
Unit measures 10.5" wide x 13" deep x 4" high and weighs 20 lbs unpacked. Includes our 30 day limited warranty.
 DYNACO STEREO 120, 2-CHANNEL STEREO POWER AMP
Cond. 8.5
$449.
 (C) R.R.

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

b&k_av2500_5-multi-channel_av_amplifier_web.jpg    

  b&k_av2500_5-multi-channel_av_amplifier_collage.jpg

          NEW LISTING 8/24/12
  (Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
B&K MULTI-CHANNEL
AV2500
5-CHANNEL
AUDIO / VIDEO POWER AMPLIFIER
#...4826

Circa 19
95

  "WORLD AC POWER"
MADE IN USA

for sale
We have complete gone through this unit and bench checked / tested it. Amp has been cleaned inside and out. All input level pots cleaned for static free performance. Internals inspected, transformer secondary's tested and our technician has completely Certified this amp. All functions have been tested and pass with flying colors!
Amp designed using Huge 'Torroidal' Power Supply Transformer. Super quality all around. From the original OM, "
The high quality parts complement include state-of-the-art solid state devices, 1% metal film resistors, computer grade electrolytic power supply capacitors, and a high capacity toroidal transformer". All 5 inputs and all 5 outputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! Following restoration procedures, we burned it in, in the shop at continuous high volume for 4 hours straight and it functioned flawlessly.
   

   On our test bench, each of this particular unit's (#...4826) FIVE (5) amplifiers produced 21.2 Volts at 8 Ohms per channel for 56 Watts / channel and 17.7 Volts at 4 Ohms per channel for 78 Watts / channel (4 Ohm operation not recommended) via discrete output transistors (5x LM3886T. (Idle AC current draw @ .38A. DC offset / out <2mV each channel.
   

   Great condition, late model, 5-Channel power amp by B&K. Model B&K AV2500. VERY versatile unit. 5-inputs and 5 outputs, Stereo and Mono Line outputs, bridge-able and more. Excellent for feeding multiple rooms / speaker systems or for use in an A/V system. Lots of punch and headroom.
   Features:
   

   - 5- Channel operation
   - 5 Discrete inputs and 5 Discrete outputs
   - 'Bridge-able' into ONE big power amp
   - Built-in Protection circuit
   - LED Status indicators
   - RCA input jacks
   - Oversize torroidal power supply transformer
- Heavy duty binding posts (can use 'single' bananas, but not standard banana pair spacing)
- Gold Plated Connectors - Improve connections for better sound and minimized signal loss and degradation.
- 1% Metal Film Resistors - Low noise resistors for better sound and a greater degree of repeatability.
- High Current - Ability to reproduce demanding recordings.
- Computer Grade Capacitors - Large capacity computer grade electrolytic capacitors for extended low frequency control and improved dynamics.
- Protection from accidental shorting of output
devices and protection from thermal overload.

   - Externally located 'mains' fuse
- 5-24VDC Control input voltage and 12VDC control voltage output (comes with 'shorting' cable to enable amp function without any corresponding control voltage in.)

-
True "
WORLD AC POWER"™ allows unit to be operated on 50 or 60 Hz AC and will select voltages from 110v, 120v, 220v and 240 Volts AC input.

 

Also from the OM:  
"The most obvious function for the AV2500 series II is to take five separate
audio inputs and provide five separate amplified outputs. Your AV2500
series II has arrived set up in this configuration.

- With the inputs buffered, a line output (OUT BUS) may be taken from
either the L BUS, R BUS, or L+R BUS and sent on to another amplifier.
This allows for linking of multiple amplifiers.
- Continuing its versatility, the AV2500 series II may be used mono to
provide one, high current channel in order to drive a speaker requiring
more power.
- As a result of the AV2500 series II’s unique bus system, the input to
channels 4 and 5 may be inverted thereby allowing the possibility of
creating a single high voltage (bridged) channel from one source, through
the left bus."


Many more features, listed in the user manual, way too numerous to mention.

 Original B&K AV2500 Specifications
(2500II specs, but essentially the same amp):
 "60 Watts per channel minimum RMS, @ 8Ohms, 1k, with no more than 0.09% THD"
   Design type: 5 Channels, Class-A/B operation
Input Sensitivity: 0.77V
Input impedance: 33.2k Ohms
THD: 0.09% @ 1kHz
   Power Bandwidth: 5Hz-45kHz
Slew Rate: 14V / mSec
Damping Factor: 80 / 8 Ohms
Signal / Noise: 95dB A weighted
Dynamic Headroom: 1dB
Max Power Consumption: 450 Watts
 
    
 Again, as stated before, our technician has completely gone thru this B&K AV2500, multi-channel Power-Amp, cleaning and testing all and it gets our full 'Certification'. Overall amp in great cosmetic condition, with only minor wear to the top cover. Unit looks, works and sounds great! Includes a pdf 'e' copy of the B&K AV2500 owners / users manual. Unit measures 17" wide x 12" deep x 3.75" high and weighs 23 lbs unpacked. Includes our standard 90 day limited warranty.
B&K AV2500 MULTI-CHANNEL POWER AMPLIFIER
Cond. 8.5
$399.

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

   

    

          NEW ADDITION 1/22/19
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED & WARRANTED 
PRE-APPRECIATED KENWOOD POWER AMPLIFIER
KENWOOD KM-106 / KM106 POWER AMP (same as KM-105 with different graphics)
'Military Market' / PX UNIT

500 WATT MONSTER!!!
#...1149
Circa 1985-86
MIJ

for sale

ü  Our technician has completely gone through and 'Certified' this unit.

ü  Unit bench checked / tested.

ü  Amp has been cleaned inside and out.

ü  Face removed, meter illumination lens removed, cleaned and reattached.

ü  All new panel illumination lamps replaced with new.

ü  All functions have been tested and pass with flying colors!

Amp designed using Huge Power Supply Transformer and oversized, vertical finned heat sink for very efficient and silent, passive cooling of output devices. All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! Following restoration procedures, we burned it in, in the shop at continuous volume for 48 hours straight and it functioned flawlessly.
   

While this amp is originally rated at 125 Watts with both channels driven (250W + 250W "Peak Music Power"), on our test bench, this particular unit's (#...1149) amplifiers produced 38 Volts at 8 Ohms per channel for 180 Watts / channel and 33 Volts at 4 Ohms per channel for 272 Watts / channel via discrete output transistors (2x Sanken 2SA1215 & 2x 2SC2921. (Idle AC current draw @ .4A.
Floor noise measured at L= 00.0mVAC and R=00.0mVAC / -60dBm) 
   

Great, later model power amp by Kenwood. Model KM-106. HUGE power output! Excellent for 2-channel (stereo) audio listening or for use in an A/V system. Lots of punch and headroom.

Kenwood KM-106 Features:
   

- Old Skoool Class A/B amplifier design (NO Digital here!)
- 2- Channel stereo operation
- A or B speaker selector via high current relay
- Dual, Vertical, 7-Segment LED Power Output Meters with Dual Position Level Selector
- Built-in Protection circuit
- LED Status indicators
- Front-mounted 1/4" stereo headphone jack
- RCA input jacks
- Dual, vertical finned internal heat sink
- Oversize power supply transformer
- 3 Rear-mounted AC convenience outlets (2 switched and 1 un-switched for a total capacity of 200 Watts)

   
Kenwood KM-106 Original Specs:

 "125 Watts per channel minimum RMS, both channels driven @ 8ohms, 20-20k, with no more than 0.03% THD"
Design type:
2 Channels, AB operation
Damping Factor: >35 @ 50Hz / 8 ohms
Signal / Noise: 120dB A weighted
Rated RMS Output: 125 Watts per channel, min. RMS, @ 8Ω, both channels driven, from 20Hz to 20kHz.
Music Power 250 Watts + 250 Watts
THD:
0.03% at 'Full Rated Output'  / 8Ω w/ 20-20kHz
0.015% @ half rated power / 8Ω w/ 20-20kHz
0.002% @ half rated power / 8Ω w/ 1kHz
IMD: 0.002% @ rated power / 8Ω
Power Bandwidth: 10Hz-50kHz @ 0.03% THD @ 8Ω
Potential Frequency Response: 5Hz-200kHz
 

Again, as stated before, our technician has completely refurb'd this Kenwood KM-106, stereo Power-Amp, cleaning and testing all and it gets our full 'Certification'. Great 'all around' power amp for about any audio system. We have sold MANY of this series of Kenwood power amps over the past 2+ decades, with never a complaint. Includes an 'e-copy' pdf download of the Kenwood KM-106 owners / users / instruction manual. Unit looks, works and sounds great! Unit measures 16.5" wide x 10.5" deep x 4.75" high and weighs 18 lbs unpacked. Includes our standard 90 day limited warranty.
KENWOOD KM-106
Cond. 8.5++
$359.

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 


Did you know?
THD (Total Harmonic Distortion) – THD is a measure of the how much a given audio device may distort a signal through the inevitable introduction of added harmonics or overtones. These figures are usually given as percentages. THD figures below approximately 1% are inaudible to most people (although market promotion efficiencies have 'brain-washed' much of the 'audio-public' into weighting low THD with almost 'holy grail' importance. I remember some manufacturers touting numbers as low as <0.003% in the early Eighties).  Low THD is not always an indication of a high quality amplifier. In fact, it is / was more commonly just the opposite. Some of the 'highest end' (read REALLY expensive) and certainly best sounding units will have distortions somewhere between .1% & 1%.
Low THD is only a simple 'bi-product' of 2 aspects. The first was an inordinate and increasing amount of 'global / negative feedback' built into amplifiers primarily to suppress distortion. This practice started to occur in the late 1970's and certainly was in 'full force' past the early 1980's for most 'main stream' consumer-grade audio amplifiers. Unfortunately this also 'suppressed' tone and 'punch' (musicality) but it made the numbers look good to the 'spoon fed' consumer (kind of like overly high speaker wattage numbers, and sorry if you're in that group and, most folks were so you're not alone). Secondly manufacturers were moving away from 'discrete-transistor' output designs to more 'monolithic' 'power-pack' output designs. While these designs reduced power supply requirements, thus reducing parts costs and weight (also translates to lower prices due to savings on freight from Asia) they generally sounded anywhere from somewhat 'anemic' compared with the designs from a few years previous, to completely 'gutless' and 'un-musical'. But, hey,… they had very low distortion figures….Can anyone say 'threw the baby out with the bath water'?
Excerpts of the above text from the website of one of the best Car Audio sites and stores in the world, 'Car-Fi' www.car-fi.com .
 

 

 


 


INTEGRATED AMPS:
 

   

 


     


         NEW LISTING 5/1/19
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED /
FULLY SERVICED & WARRANTED
OLD-SCHOOL, 2-CHANNEL STEREO
VINTAGE PIONEER STEREO INTEGRATED AMPLIFIER
PIONEER SA-9100 / SA9100
#...540M
Circa 1973-75 
"WORLD AC POWER"
MIJ
SOLD 9/25/19
SHIPPING TO JEREMY IN CALIFORNIA

 
 

ü  Our technician has completely gone through and 'Certified' this unit.

ü  Everything was cleaned inside and out including all switches, controls and contacts. Cleaned and re-lubed all control shafts.

ü Internal fuses checked for correct value / function and replaced where necessary.

ü Original issues were 'early clipping' on Right channel 'Positive' peak (visible on Oscilloscope), Quite high DC at speaker outputs, the AWR-032 power supply board that had completely wrong Voltage values on one side and a 'popping' 'Tone Defeat' and 'Filter' Switch circuit boards (AWK-021 & AWS-040) (most rectified following below service).

ü Replaced 20+ electrolytic capacitors as well as some transistors and resistors

ü Solder joints reflowed on probable high heat and high stress points

ü New 8V lamps installed (#25-140)

ü Following 10-min warm-up Amplifier section had output bias and DC offset adjusted to spec levels

ü All functions tested for perfect operation.

ü Following above procedures, unit was cosmetically detailed inside and out.

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours. (Technicians note, "this is a very 'tech friendly & serviceable' amplifier design")
Total tech time
25+ hours.

   
While this unit was originally rated at 60 WPC @ 8Ohms, on our test bench, the internal amplifiers of this particular Pioneer SA-9100, Integrated Amplifier, #...1869, produced 24+ Volts per channel for 75+ Watts per channel at 8 Ω and 20+ Volts at 4 Ω for 100 Watts per channel via discrete, metal cased, TO-3 style outputs @ 1khz. (2x Toshiba 2SA679 & 2x Toshiba 2SC1079 devices)
(Idle Mains AC current draw @ 420 mA.
Bias set to spec / 25mVDC
DC offset brought from 80 & 105 mVDC to <2mVDC following power supply circuit board rebuild and driver board refurb

 Floor noise measured at L= 3mVAC and R=3mVAC)

   ____________________________
  
Powerful and Versatile, Pioneer 'Flagship' for 1973, the SA-9100 integrated amplifier. This is one of the most 'meticulous' built amps out of Japan we have seen. Incredibly well designed and built. Great amp for serious 2-channel, home-audio and "recording studio" use. "Real" TO-3 outputs and HUGE power supply!

Pioneer SA-9100 Features include:
  

- Very well built output section and serious power supply 
- Speaker selector for A or B or C, A+B, A+C or Off 
- Incredible 'Single-Ended / Push-Pull' EQ circuit that is physically 'fully shielded'
- Separate Bass and Treble with high quality, de-tented controls utilizing "fixed resistors and capacitors" at 2dB intervals, as opposed to typical carbon trace. This is a VERY expensive style of potentiometer to design into a unit. They are not prone to the "scratchiness" / dirt that most variable resistors are.
- Dual Bass controls centered at 50Hz and 100Hz
- Dual Treble controls centered at 10kHz and 20kHz
 - Tone-Defeat feature. Bypasses tone control circuitry for purest signal path
- Built-in Low / Sub-Sonic filter for cutting turntable rumble. Center selectable for either 'Subsonic' 8Hz or Low-Cut 30Hz
 - Built-in High filter for reducing 19 kHz FM pilot tones and tape hiss. Center selectable for either 8kHz or 12kHz
- Triple-Range Attenuation selector for volume pot to allow 'finer' adjustment
-Rear located controls for adjusting the levels between 'AUX-2', 'Phono-2' & 'Speaker-2' for 'comparative' listening tests
- Instant Audio-Muting for either-15dB or-30dB attenuation
- Dual tape monitors
(Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Tape 'Duplicate' / dubbing capability
- Dual AUX Inputs
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
 - Tuner input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Dual Phono / Turntable inputs with Built-In Phono Pre-Amp
- Phono impedance selectable for either 25, 50, or 100kΩ
- Stereo Mode switch for Stereo / Mono-Mix / Stereo-Reverse, L or R selector
- Speaker output protection circuit (not just a fuse as is typical in 'Vintage' gear)
- Front mounted 1/4" stereo headphone jack
 - Pre-Amp out / Power-Amp In RCA loop with built-in Connect / Separation switch.
- Triple AC outlets ( 1 switched, 2 un-switched) for a total capacity of 200 Watts
- True "
WORLD AC POWER"™ allows unit to be operated on 50 or 60 Hz AC and will select voltages from 110v, 120v, 220v and 240 Volts AC input.

  

Pioneer SA-9100 Original Specs:

   

Design type: 2 Channels, Integrated Pre /
 Class AB operation Power Amplifier.
"2-Stage Differential Amplifier, Direct Coupled, Pure Complementary OCL"
Rated Power output: 60 WPC min RMS @ 8 Ohms & 75 WPC min RMS  @ 4 Ohms and < 0.1% THD across 20-20kHz
(75Wpc and 100Wpc at 8 & 4 Ohms w/ 1kHz)

Damping Factor:
>70 @ 20-20kHz into 8Ω
THD & IMD; 0.1% at full rated power into 8Ω w/ 20-20kHz @ 0.04% @ 1W
Freq Response: 7Hz-80kHz at full rated power
 / Power Bandwidth = 5-40kHz
S/N:
>95dB for 'Power Amp' inputs

Input Sensitivity Power Amp: 500mV @ 50k Ohms

PRE-AMP SECTION SPECS:

Pre-Amp Output (full output): 2V @ 8 Ohms
S/N: 93dB for Tuner, Tape and AUX inputs
Input Sensitivities 'Tuner, AUX 1 and Tape' inputs: 150mV / 100KΩ
Input Sensitivities AUX 2: 150mV to 1.5V /
50kΩ or 100kΩ
Microphone: 2.0mV @ 50k Ohms
Mic input Freq Response: 10Hz-10kHz
Bass Control (main); ±10dB @ 100Hz
Bass Control (sub); ±6dB @ 50Hz
Treble Control
(main); ±10dB @ 10kHz
Treble Control (sub); ±6dB @ 20kHz
Subsonic Filter: 8Hz, 12 dB/Oct
Low
Filter: 30Hz, 12 dB/Oct
High Filter: 8kHz or 12kHz, 12 dB/Oct

Loudness Control: +10dB @ 100Hz (-40dB Vol Level)

  

 Phono Section:
Freq Response: 30Hz-15kHz w/ RIAA Equalization of ±0.3dB
S/N: >80dB w/ 5mV signal input

Phono 1 / MM Sensitivity: 2.5mV / 50
Ω
Phono 2 Sensitivity: 2.5mV-10mV / 25
Ω, 50kΩ or 100kΩ
Phono MM Maximum Input Level: 250mV RMS / 700mV P-P

 

Again, we have complete gone through and tested all functions of this unit. The only thing we weren't able to completely address, was the 'popping' on the 'Tone Defeat' and 'Filter Switches'. We improved it to a tolerable level on the 'Filter Switches'. The 'Tone Defeat' switch still pops, but as it's a switch that is typically 'set and left', we did not want to invest the additional resources to rectify, thus having to reflect it in higher final price. We felt that was the best decision.
Overall, the unit
sounds incredible. This is only the second of this model we have had in 20+ years of being on the web! This is an incredible amp and way better built and more versatile than most we've seen marketed since it's 1973 introductory date. Internally designed and built with very expensive, 5% & 1% tolerance resistors and +/- 2% tolerance capacitors throughout! That was fairly 'unheard of' at the time for most audio gear being generally reserved for TOTL models. Our 'tech' first noticed that while doing it's 'workup' and made note on the worksheet, then we read about it in the owners manual. Unit looks fabulous after detailing. Original brushed aluminum face and all original 'milled' aluminum knobs look near new. Only 'barely mentionable' cosmetic issue are some small, 'moisture' stains on the wood case top (see photos above). Real Walnut Wood veneer case just had a fresh coat of Howards Feed-n-Wax and looks great! Again, all functions test perfectly after our service work and it sounds great!
Comes with an 'e-copy', PDF download of the Pioneer SA-9100 owners / users / instruction manual and the service manual if the purchaser desires. Measures 17" wide x 13.5" deep x 5.5" tall and weighs 34 lbs unpacked.
Comes with our 90 day limited warranty.
PIONEER SA-9100 INTEGRATED STEREO AMPLIFIER
Cosmetic Cond. 8.5+

SOLD 9/25/19
SHIPPING TO JEREMY IN CALIFORNIA

(Cons. M.H.)


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
  


 

        

 


NEW ADDITION
8/16/19
 (Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED & WARRANTED
OLD-SCHOOL, 2-CHANNEL STEREO
VINTAGE KENWOOD STEREO INTEGRATED AMPLIFIER
KENWOOD
KA-501 / KA501
#...5479
  Circa 1980-84
MIJ

for sale


ü  Our technician has completely gone through and 'Certified' this unit.

ü  Everything was cleaned inside and out including all switches, controls and contacts.

ü Internal fuses checked for correct value / function and replaced where necessary (actually replaced a couple ‘incorrect’ values).

ü  Solder joints reflowed on all possible high heat and stress points

ü Amplifier section had output bias and DC offset checked to spec levels after 10 min warm-up.

ü All functions tested for perfect operation.

ü Following above procedures, unit was cosmetically detailed inside and out.

ü Power meter illumination lamps in working condition

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours.
Total tech time 6.5+ hours.


On our test bench, each internal amplifier of this particular unit, #...5479, produced peak power of 26+ Volts per channel at 8 ohms for 84+ Watts per channel and 22.5 Volts at 4 ohms for 126 Watts per channel via discrete output transistors (2x 2SA1094 & 2x 2SC2564).
DC offset set to no greater than 35 mVDC (unloaded) either channels. AC Idle current at 125 mA. Floor noise >-60dBm.
 
____________________________

Great performing, Silver Face, Integrated Amplifier, the Kenwood KA-501. Brushed aluminum milled face with all original matching brushed aluminum knobs. It's got a few 'battle scars', such as a missing power switch bat (still usable), some scuffs on the bezel around the power meters, a few scuffs / striations on a knob or two, a few tics along the top edge, and some bumps and bruises to the top, sheet metal covering, but overall, still great looking. Great amp for about any 2-channel, audio system. LOT's of punch and headroom. Check out the 'Slew Rate' and 'Damping Factor' in the specs. Very Impressive! Among the best we have seen in 'consumer' grade audio equipment and way beyond many 'Pro' audio power amps!
Big Power very musical sounding amp.

Kenwood KA-501 Features include:

 
 
- Discrete Outputs
- Large, power supply for plenty of headroom 
- Speaker selector for A or B, A+B or Off 
- Separate Bass and Treble controls, utilizing super quality de-tented pots and are 'de-featable' for purest signal path
- 'DC' switch to 'Direct Couple' signal path for purest audio
- Oversize Volume control pot utilizing super quality de-tented type
- Phono / turntable input with built-in cartridge pre-amp

- Dual Tape Monitors with dubbing
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc. as well as for CDR)
- AUX Input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tape Dubbing A->B Capability
- Tuner input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tape B features DIN as well as standard RCA I/O's
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- Built-in Low / Sub-Sonic filter for cutting turntable rumble.
- Front mounted 1/4" stereo headphone jack
- Binding Post Speaker connectors
- Oversize, Rear 'Service Bumpers'

- Triple convenience AC outlets; 2 Switched and 1 un-switched for a total capacity of 500 Watts

Kenwood KA-501 Original Specs:
 
 
Design type: 2 Channels, AB operation
Rated RMS Output: 70 Watts per channel, min. RMS, at 8 Ohms, both channels driven, from 20Hz to 20kHz.
Transient Response:
Damping Factor DC-20,000 / 8Ω:
60
Rise Time DC-20,000 / 8Ω:
1.0 μs
Slew Rate DC-20,000 / 8Ω:
110 V/μs (All Very Impressive!)
Power Bandwidth: 5Hz-40kHz @ 0.03% THD @ 8Ω
THD; 0.03% at full rated power (70W) into 8Ω w/ 20-20kHz.
Potential Frequency Response: DC Coupled 'On' = 50-300kHz +0dB / -3dB
S/N on Phono MM w/ 2.5mV signal: 86dB
Input Sensitivity Phono (MM): 2.5mV @ 50kΩ
Input Sensitivity Tuner / AUX / Tape: 150 mV @ 50kΩ
Phono MM Maximum Input Level: 240mV
Phono Frequency Response (RIAA standard Curve
± 0.3dB): 20Hz-20kHz
Tape Rec Level (Via RCA's): 200 mV @ 120Ω
Bass Control; ±10dB @ 100Hz
Treble Control; ±10dB @ 10kHz
Subsonic Filter: 18Hz, 12 dB/Oct

Loudness Control: +8dB @ 100Hz (-30dB Vol Level)


Great unit to provide the basis of a medium to medium large sized Hi-Fi system or 'project home studio'. Again, we have completely gone through it as stated above. With the exception of the above mentioned issues, the unit is in decent cosmetic condition. Unit functions and sounds great!
Measures 17.5" wide x 16.25" deep x 6.25" tall and weighs 24 lbs unpacked. Includes our 90 day limited warranty!
Cond. 8.5
KENWOOD KA-501
$589.
(Cons. M.H.)



(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
  


 

 

    

        NEW LISTING 5/1/19
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED & WARRANTED
VINTAGE PIONEER STEREO INTEGRATED AMPLIFIER
PIONEER SA-6500-II / SA6500-II
#...352F
Circa 1977-79
MIJ
for sale

ü  Our technician has completely gone through and 'Certified' this unit.

ü  Everything was cleaned inside and out including all switches, controls and contacts. Cleaned and re-lubed all control shafts.

ü  Internal fuses checked for correct value / function and replaced where necessary.

ü  Input function switch replaced as the original had intermittent issues

ü  Headphone circuit board repaired as one channel was in-op.

ü  Solder joints reflowed on probable high heat and high stress points

ü  New AC Power / Pilot lamp installed

ü  Amplifier section had output bias and DC offset checked to acceptable levels after 10 min warm-up.

ü  All functions tested for perfect operation.

ü  Following above procedures, unit was cosmetically detailed inside and out.

ü  All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü  Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours. (Technicians note, "this is a very 'tech friendly & serviceable' amplifier design")
Total tech time 6+ hours.

     
On our test bench the internal amplifiers of this particular unit, #...352F, produced 18+ Volts per channel at 8 Ohms for 40+ Watts per channel and 14+ Volts at 4 Ohms for 49+ Watts per channel via discrete outputs (2x NEC 2SB616A & 2x NEC 2SD586)
Idle 'Mains' current draw  0.1A.
Floor noise measured @ >-60dBm.
    
____________________________
    
Great performing and 'classic' looking Pioneer Integrated Amplifier. The Pioneer SA-6500. This is the first of this model we've had. Great unit to provide the basis of a medium to medium large sized Hi-Fi system or 'project home studio'. Following the above refurb / service work, the unit now works well and sounds great!

Pioneer SA-6500-II Features include:
   

- Discrete Amplifier Output design 
- Speaker A, B Off selector
- Separate Bass and Treble controls featuring high-quality, de-tented controls
- "Tone" switch to bypass tone controls for purest, most un-adulterated signal path
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- Dual tape deck monitors
(Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Tape Dubbing 1->2 Capability
- Phono / Turntable input with Built-In Phono Pre-Amp
- AUX Input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- 1/4" stereo headphone jack
- Spring loaded, 'Push'' speaker outputs
- Quad AC Convenience outlets (2 switched and 2 un-switched) with a total capacity of 400 Watts

    
Pioneer SA-6500-II Original Specs:
   
 
"Continuous Power Ouput is 30 Watts / Ch. min RMS, @ 8 Ohms or 30 Watts / Ch @ 4 Ohms from 20-20kHz w/ < 0.1% THD."
Design type:
2 Channel, discrete output
Damping Factor @ 1kHz / & 20-20kHz: 30
THD; 0.1% at full rated power (30W + 30W) into 8
Ω w/ 20-20kHz
Potential Frequency Response @1W: 10-40kHz +/-0dB

S/N: 93dB for Tuner, Tape and AUX inputs
Bass Control: +9dB /-8dB @ 100Hz
Treble Control: 
+8dB /-6dB dB @ 10kHz

Loudness Control: +8dB @ 100Hz & +5dB @ 10kHz (-40dB Vol Level)

Input Sensitivities: Non-Phono inputs = 150mV / 50kΩ
Non-Phono Inputs: 150mV / 50kΩ
Tape outputs: 150mV / 50kΩ

PHONO SECTION SPECS:
Freq Response:
20Hz-20kHz w/ RIAA Equalization of ±0.3dB
S/N: >72dB
Input Sensitivity: 2.5mV @ 50kΩ
Phono Overload: 200mV


From the original Pioneer SA-6500-II Brochure;
"Bass Frequencies Sweet and Clean. The many refinements in the SA-6500-II include a constant-current load construction in the 'pre-driver' stage of the power amplifier. This helps eliminate a time constant at low frequency so that sound quality remains un-muddied and sweet over the whole audible spectrum....Further the power output is enhanced with a power supply using a larger transformer and a pair of 6,800uF, Electrolytic Capacitors for excellent Voltage Regulation so that low-range dynamics never suffer power drain" (means tighter, deeper and 'thumpier' bass!)

Again, we have completely gone through the unit cleaning all contacts, pots, switches and controls as mentioned above. All functions test as original. Simple to use. Unit performs and sounds great! 
Other than a few typical, light scuffs / striations on the sheet metal bonnet, nothing really worth mentioning cosmetically. Unit looks great!
Comes with an 'e-copy', PDF download of the Pioneer SA-6500-II owners / users / instruction manual, brochure and the service manual if the purchaser desires.
Measures 15" wide x 12.25" deep x 5.5" tall and weighs 17 lbs unpacked. Comes with original owners manual and includes our 90 day limited  warranty.
Condition 8.5
PIONEER SA-6500-II
$489.
(Cons. M.H.)



(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
  


 

 

    



NEW ADDITION
8/20/19
 (Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED & WARRANTED
OLD-SCHOOL, 2-CHANNEL STEREO
VINTAGE KENWOOD STEREO INTEGRATED AMPLIFIER
KENWOOD
KA-6004 / KA6004
BIG 'DYNAMIC' POWER AND LOADS OF INPUTS!!!
#...1687
  Circa 1973-76
"WORLD AC POWER"
MIJ

for sale


ü  Our technician has completely gone through and 'Certified' this unit.

ü  Everything was cleaned inside and out including all switches, controls and contacts.

ü Internal fuses checked for correct value / function and replaced where necessary (actually replaced a couple ‘incorrect’ values).

ü Power switch was arching, so it was disassembled, and contacts burnished, re-lubed and re-assembled

ü Solder joints reflowed on Tone Control Circuit Board, and 'Filter Switch' circuit board, and the balance of all possible high heat and stress points

ü Amplifier section had output bias set to correct 40mA from existing (and erroneous) 60+mA.

ü  DC offset set to < 10mVDC either channel from existing 25+mVDC

ü All functions tested for perfect operation.

ü Following above procedures, unit was cosmetically detailed inside and out.

ü Even though all Power and Function Indicator illumination lamps were in working condition, we replaced all; 6x #25-130 and 1x #1302

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours.
Total tech time 13 hours.


On our test bench, each internal amplifier of this particular unit, #...1687, produced peak power of 20+ Volts per channel at 8 ohms for 54+ Watts per channel and 17 Volts at 4 ohms for 72 Watts per channel via discrete, metal cased, TO-3 output transistors (2x 2SA744 & 2x 2SC1402).
DC offset set to no greater than 10 mVDC (unloaded) either channels. AC Idle current at 300 mA. Floor noise >-60dBm.
 
____________________________

Great performing, Two-Tone, Silver & Bronze Face, Integrated Amplifier, the Kenwood KA-6004. Brushed aluminum milled face with all original matching brushed aluminum knobs. It's got its share of 'battle scars', most noticeably, dozens of small tics / pecks around the volume knob and a couple dozen around the left side (not sure what someone was doing to cause that), and a few other blems (see photos above). From some angles, the tics / pecks aren't too bothersome, from others, you'll see them. Original, 'Plastic' toggle bats replaced with 'Metal' handles.
Great amp for about any 2-channel, audio system. LOT's of punch and headroom. VERY MUSICAL SOUNDING!!!
Big Power with LOTS of INPUTS!

Kenwood KA-6004 Features include:

 
 
- Discrete Output Transistors
- Large, power supply for plenty of headroom 
- Speaker selector for A or B, A+B or Off 
- Separate Bass and Treble controls, utilizing NOT pots, but a 2dB, 'Wafer Attenuator' and are TRUELY 'de-featable' for purest signal path when set to 'OFF'
- Serviceable, 'Open' body switches for ease of future cleaning
- Dual Tape Monitors with Bi-Directional dubbing
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc. as well as for CDR)
- Dual AUX Inputs
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Both Tape I/O's feature DIN as well as standard RCA I/O's
- Dual Phono / turntable inputs with built-in cartridge pre-amp

- Stereo Mode switch for Stereo / Mono-Mix / Stereo-Reverse, L or R selector (very handy for trouble-shooting system and speakers

- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
Dual, Built-in Low / Sub-Sonic filters for cutting turntable rumble / hum. 40Hz and 80Hz
- Built-in High filter for @ 7 kHz. Great for reducing AM noise
 - Instant -20dB Audio-Muting / Volume attenuation

- Front mounted 1/4" stereo headphone jack
- Front mounted. L&R 1/4" 'Microphone' jacks (be careful running microphones into your 'home audio' speakers)
- Rear located 'Mains' protection fuse

 - Pre-Amp out / Power-Amp In RCA loop with built-in Normal / Separate switch (no need for jumpers).

- Quad convenience AC outlets; 3 Switched and 1 un-switched for a total capacity of 300 Watts

- True "
WORLD AC POWER"™ allows unit to be operated on 50 or 60 Hz AC and will select voltages from 110v, 120v, 220v and 240 Volts AC input.

Kenwood KA-6004 Original Specs:
 
 
Design type: 2 Channels, AB operation
Dynamic Power: 220 Watts / Channel @ 4 Ohms
Rated RMS Output: 40 Watts per channel, min. RMS, at 8 Ohms, both channels driven, from 20Hz to 20kHz.
Damping Factor DC-20,000 / 8Ω:
32

Power Bandwidth: 10Hz-40kHz
THD; 0.5% at full rated power (40 W) into 8Ω w/ 20-20kHz.
S/N on Phono MM w/ 2.5mV signal: 68dB
S/N on Tuner / AUX / Tape w/ 110mV signal: 75dB
Input Sensitivity Phono (MM): 2.5mV @ 50kΩ
Input Sensitivity Microphone: 3mV @ 50kΩ
Input Sensitivity Tuner / AUX / Tape: 200 mV @ 100
Input Sensitivity Main Amp: 1V @ 50kΩ
Tape Rec Level (Via RCA's): 200 mV
Tape Rec Level (Via DIN): 40 mV
Bass Control; ±10dB @ 100Hz (2dB 'Step Switch Attenuator)
Treble Control; ±10dB @ 10kHz (2dB 'Step Switch Attenuator)
Subsonic Filter: 40Hz, 12 dB/Oct

Low Filter: 80Hz, 12 dB/Oct
High Filter: 7kHz, 6 dB/Oct

Loudness Control: +8dB @ 100Hz & +3dB & 10kHz (-30dB Vol Level)


Great unit to provide the basis of a medium to medium large sized Hi-Fi system or 'project home studio'. Again, we have completely gone through it as stated above. Again, it's got a few 'battle scars', but that doesn't impede it's performance. Unit functions and sounds great!
Measures 17.2" wide x 11.75" deep x 6.1" tall and weighs 26 lbs unpacked. Includes our 90 day limited warranty!
Cond. 7.5 (due to tics / pecks / blems)
KENWOOD KA-6004
$449.


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
  


 

 

    

         NEW LISTING 3/21/19
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE TECHNICS STEREO INTEGRATED AMPLIFIER
TECHNICS SU-7300 / SU7300
#...B051

MIJ
Circa 1976-78 

for sale

ü  Our technician has completely gone through and 'Certified' this unit.

ü  Everything was cleaned inside and out including all switches, controls and contacts. Cleaned and re-lubed all control shafts.

ü Internal fuses checked for correct value / function and replaced where necessary (actually replaced a couple ‘incorrect’ values).

ü  Solder joints reflowed on all possible high heat and stress points

ü  Amplifier section had output bias and DC offset checked to spec levels after 10 min warm-up.

ü  All functions tested for perfect operation.

ü  Following above procedures, unit was cosmetically detailed inside and out.

ü  Power meter illumination lamps replaced with new, fresh bulbs (even though originals were working, old lamps commonly don’t survive SHIPPED)

ü  All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü  Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours. (Technicians note, "this is a fairly 'tech friendly & serviceable' amplifier design")
Total tech time 5+ hours.


On our test bench, each internal amplifier of this particular unit, #...B051, produced peak power of 20.5 Volts per channel at 8 ohms for 55+ Watts per channel and 17 Volts at 4 ohms for 76 Watts per channel via discrete output transistors.
DC offset set to no greater than 10 mVDC both channels. AC Idle current at 270mA. Floor noise >-60dBm.
 
____________________________
 

This Brushed Aluminum Face Technics SU-7300 Stereo Integrated Amplifier looks and sounds great! Great amp for 2-channel stereo systems up to medium-large and "recording studio" use. "Real" output transistors and substantial power supply! Just a great 'all-around utility' amplifier for probably more than 80% of the audio systems out there.
 
Technics SU-7300 Features include:
 

- Real Class A/B amplifier architecture
- Large (2.5 inch wide), dual analog VU power meters w/ ‘Dual’ ranges
- A or B speaker select
- Super quality de-tented volume control
- Separate Bass and Treble with high quality de-tented controls
- Dual tape deck monitors with 'Tape-2' having a DIN as well as RCA I/O's. (Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Bi-Directional Tape Dubbing capability
- Phono / Turntable input w/ built-in Phono Pre-Amp

- Tuner input (can also be used for ( Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® etc. inputs)
- Loudness function to increase ‘fullness’ of sound at lower volume levels by accentuating the Lower and Upper frequencies relative to the mid range.
- Meter range select (x1 or x0.1)
- Built-in High filter for reducing 19 kHz FM pilot tones and tape hiss and AM noise

- Front mounted
¼" stereo headphone jack
- Back panel features full RCA patch bay for all inputs. Binding post speaker connectors for A&B and Dual AC convenience outlets 1 Switched and 1 un-switched AC outlets for a maximum load of 250 watts of external gear.

 
Technics SU-7300 Specifications:
 
 
Output: Continuous 41 Watts per channel, min. RMS, at 8 Ohms & 48 Watts per channel, min. RMS, at 4 Ohms, both channels driven, from 20Hz to 20kHz.
Design type: 2 Channels, Integrated Pre /
 Class A/B operation Power Amplifier
Damping Factor: >40@ 20-20kHz into 8Ω
THD and IMD: 0.08% at full rated power into 8Ω w/ 20-20kHz & 0.04% @ half power
Freq Response of Pre-amp: 7Hz-80kHz
S/N: 97dB for Tuner, Tape and AUX inputs
Bass Control:  ±12dB @ 50Hz
Treble Control: ±12dB @ 20kHz
High Filter:  -6dB / oct @ 8kHz
Loudness Control: +8dB @ 100Hz (-30dB Vol Level)
Input Sensitivities: Non-Phono inputs = 150mV / 47kΩ
Tape outputs: 150mV

PHONO SECTION SPECS:
Freq Response:
RIAA standard w/ RIAA Equalization of ±0.3dB
S/N: >78Db
Residual hum and noise: 0.6mV
Input Sensitivity: 2.5mV @ 47kΩ
Phono Overload: 150mV



Again as stated earlier, the Amp has had our standard FULL SERVICE inside and out including cleaning all control pots and contacts, replacing any necessary parts, and completely tested. All functions have been tested and pass with flying colors! New meter lamps installed for trouble-free service. Face and knobs are in excellent condition. Unit looks and sounds great! Measures 17½" wide x 14" deep x 5½" tall and weighs 20 lbs unpacked. Includes our 90-day limited warranty!
TECHNICS SU-7300
 Cond. 8.5
 
$429.

(Cons. M.H.)


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

 

       

NEW ADDITION 5/21/18
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED
VINTAGE
FISHER INTEGRATED POWER AMPLIFIER
FISHER CA-271 (CA-1271)
FISHER "STUDIO STANDARD"
STEREO INTEGRATED AMPLIFIER

#...8505
Circa late 1980's
MIJ
for sale


ü  Our technician has completely gone through and 'Certified' this unit.

ü  Following both internal and external visual inspection, the entire unit was cleaned out including all contacts, switches and controls. Switches now clean sounding and performing fine.

ü Silicone heat sink compound inspected for ‘suppleness’

ü Output section bias / DC offset adjusted to factory spec.

ü Solder joints reflowed on all possible high heat and stress points

ü 'Meter' illumination bulbs replaced with new, and balance of indicators checked

ü All functions tested for perfect operation.

ü All inputs and functions tested.

ü Both amplifier sides produce clean and even sine waves! No power supply hum of any kind. It's dead silent!

ü Following electronic refurbishing, the entire unit was cosmetically detailed

ü Following restoration procedures, the unit was ran continuously at medium volume, as all our amplifier / receivers are, into a 4 Ohm load with "Loudness" on and both Tone Controls at 10 for 48 hours.

On our test bench, each internal amplifier of this particular unit, #...8451, produced peak power of 34
Volts @ 8Ω per channel for 144 Watts / channel and 28 Volts @ 4Ω per channel 196 Watts / channel via 4 discrete, Toshiba output devices at 1khz. (2x 2SA-1095 & 2X 2SC2565). AC Idle current at .5A.  DC offset adjusted to <.5mV!!! L&R.  Floor noise <0.1mVAC.
____________________________

We've had three of these, and got over 'being surprised' by their performance. This Fisher CA-271, Integrated Amplifier was a 'sleeper' when we originally acquired it. We thought they were too 'recent' to bother with, but then we did our preliminary tests and quickly changed our opinion. Once our tech got finished with it, we were thoroughly surprised and impressed. They always have a lot of punch and headroom (check our bench test results above against it's original specs) and are VERY MUSICAL sounding. Large internal power supply, relative to most amps in it's range. Unit looks good with minor, typical wear, mostly to edges. Nothing distracting.

 
____________________________

Fisher CA-271Features include:

- 5-Band, 'Graphic' EQ with centers as follows: 63Hz, 250Hz, 1kHz, 4kHz, and 16kHz.
- Independent speaker selector switches for A, B, A+B, Off
- Phono / Turntable input with Built-In Phono Pre-Amp
- Tape-1 monitor (can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR {CD recorders} ) BUT since ‘TAPE-1’ is a ‘Tape Input’ and not a ‘Tape Monitor / Loop’ it CANNOT BE USED for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Aux / ‘Video Sound’ input
(can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®)
- Loudness for enhancing Bass and Treble response at lower volume levels
- Dual 7-Segment, LED Level Meters
- Meter Range Selector
- 2-Pin, DC power output for other Fisher components from that series that was 'proprietary'.
- Front mounted, ¼”, Stereo headphone jack

Original FISHER CA-271 Specifications:

AMP SPECIFICATIONS:

Power output: 100WPC min RMS @ 8 Ohms & no more than 0.05% THD @ 20-20kHz
THD: <0.05% @ full rated power
IHF IMD: 0.05% @ full rated power & 8 Ohms
Freq Response of power amp section: 20Hz to 20kHz w/ deviation of ±0.2dB
Damping factor: >20 @ 8Ω / 1kHz
Signal to noise ratio: 90dB (line)
Input sensitivity - Phono / All Others:
2.5mV (MM) /  150mV (all at 50kΩ)
EQ with centers as follows: 63Hz, 250Hz, 1kHz, 4kHz, and 16kHz.
Loudness Control:
+8dB @ 100Hz  and +4dB @10kHz
Max Power Consumption:
480 Watts

PHONO SECTION SPECS:
Freq Response:
20Hz-20kHz w/ RIAA deviation of ±0.2dB
S/N: >70dB
Input Sensitivity: 2.5mV @ 50kΩ
Phono Overload: 125mV


Again, we have done the previously stated refurbishment / restoration work on this unit to insure it's performance, and it gets our full 'Certification'. All functions tested for perfect operation. Performs and sounds great! This unit will also supply power to many 'proprietary Fisher' units from this series, such as Fisher Tuners and Cassette Decks.
 We can include an 'e' copy, PDF of the Fisher CA-271 / CA-1271 Service manual if the purchaser wishes. Measures
17.25" wide x 4.25" tall x 10.5" deep and weighs an impressive 20 lbs unpacked.
Includes our standard 90 day limited warranty.
 
Cond. 8.5
FISHER CA-271 INTEGRATED AMPLIFIER
$339.


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

 

 



 


 

 


SOLD ITEMS BELOW


 


TO SEE OUR ARCHIVE OF SOLD AMPS & PREAMPS CLICK HERE
 



     


               NEW LISTING 1/11/19
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE PIONEER STEREO INTEGRATED AMPLIFIER
PIONEER SA-7500 / SA7500

MIJ
Circa 1976-78

SOLD 3/17/19
SHIPPED TO STEVE IN CONNECTICUT

ü  Our technician has completely gone through and 'Certified' this unit.

ü  Everything was cleaned inside and out including all switches, controls and contacts. Cleaned and re-lubed all control shafts.

ü Internal fuses checked for correct value / function and replaced where necessary.

ü  Solder joints reflowed on all possible high heat and stress points

ü  Amplifier section had output bias and DC offset adjusted to spec levels after 10 min warm-up.

ü  All functions tested for perfect operation.

ü  Following above procedures, unit was cosmetically detailed inside and out.

ü 
Surface corrosion painstakingly removed from all RCA I/O jacks and binding post flanges

ü  All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü  Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours. (Technicians note, "this is a very 'tech friendly & serviceable' amplifier design")
Total tech time 7 hours.


On our test bench, each internal amplifier of this particular unit, #...328M, produced peak power of 21 Volts per channel at 8 ohms for 55 Watts per channel and 17 Volts at 4 ohms for 76 Watts per channel via TO3, metal cased, discrete output transistors (2x 2SB541 & 2SD388).
DC offset set to 0 mVDC both channels w/ 5.1k Ohms shorting plugs. Bias set to correct 30mVDC

AC Idle current at 200mA. Floor noise >-60dBm.
 
____________________________
 

Great performing, sounding and Versatile, Pioneer SA-7500 integrated amplifier. Great amp for 2-channel stereo systems up to medium-large and "recording studio" use. "Real" output transistors and substantial power supply! Just a great 'all-around utility' amplifier for probably more than 80% of the audio systems out there.

Pioneer SA-7500 Features:
 

- Speaker selector for A or B, A+B or Off 
- Super quality volume attenuator
- Separate Bass and Treble with high quality
de-tented potentiometers
- Tone-Defeat feature. Bypasses tone control circuitry for purest signal path
- Bass Tone control center selectable for either 200Hz or 400Hz
- Treble Tone control center selectable for either 2.5kHz or 5kHz-
 Built-in Low / Sub-Sonic filter for cutting turntable rumble / feedback
- Built-in High filter for reducing 19 kHz FM pilot tones and tape hiss and AM noise
 - Instant -20dB Audio-Muting / Volume attenuation
- Dual tape deck monitors with 'Tape-2' having a DIN as well as RCA I/O's. (Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Tape Dubbing Capability
- Dual Phono / Turntable inputs w/ built-in Phono Pre-Amp
- AUX Input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input (can also be used for ( Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® etc. inputs)

- Stereo Mode switch for Stereo / Mono-Mix / Stereo-Reverse, L or R selector (very handy for trouble-shooting system and speakers
- Front mounted 1/4" stereo headphone jack
- Rear mounted, 1/4" microphone input
- Pre-Amp out / Power-Amp In RCA loop to connect the pre-amp to a larger power or an 'additional' power amp, or to use the 'power-amp' with another system such as in a small PA system.
- Triple AC convenience outlets with 2 switched and 1 un-switched for a total capacity of 200 Watts of accessories

 
Pioneer SA-7500 Specifications:
 
 
Output: Continuous 40 Watts per channel, min. RMS, at 8 Ohms & 45 Watts per channel, min. RMS, at 4 Ohms, both channels driven, from 20Hz to 20kHz.

Design type: 2 Channels, Integrated Pre /
 Class A/B operation Power Amplifier
Damping Factor: >25@ 20-20kHz into 8Ω

THD: 0.3% at full rated power into 8
Ω w/ 20-20kHz & 0.05% @ half power (20 WPC)
Freq Response of power amp: 10Hz-80kHz
Freq Response of Pre-amp: 10Hz-50kHz

S/N: 90dB for Tuner, Tape and AUX inputs
Bass Control:  ±7dB / ±11dB @ 100Hz
Turnover selectable 200Hz / 400Hz
Treble Control:  ±7dB / ±11dB @ 10kHz
Turnover selectable 5kHz / 2.5kHz
Subsonic Filter:  -6dB / oct @ 30Hz
High Filter:  -6dB / oct @ 8kHz

Loudness Control: +8dB @ 100Hz & +4dB @ 10kHz (-40dB Vol Level)

Input Sensitivities: Non-Phono inputs = 150mV / 50kΩ
Input Sensitivity Power Amp: 1V / 50kΩ
Tape outputs: 150mV
Pre-Amp
outputs: 1V
M
icrophone Sensitivity Power Amp: 7.5mV
/ 85kΩ

PHONO SECTION SPECS:
Freq Response:
30Hz-15kHz w/ RIAA Equalization of ±0.3dB
S/N: >70dB
Input Sensitivity: 2.5mV @ 50kΩ
Phono Overload: 200mV

 
Again, we have complete gone through and tested all functions of this unit. It sounds incredible. Unit looks great with only slight, minor cosmetic issues to the face (see lower right photos above). All functions test perfectly and it sounds great! Again, great amp for medium to med-large audio systems, and where someone needs a 'solid' amount of features without 'fluff'. Comes with an 'e-copy', PDF download of the Pioneer SA-7500 owners / users / instruction manual and the service manual if the purchaser desires. Measures 16.5" wide x 13.5" deep x 5.75" tall and weighs 27 lbs unpacked.
PIONEER SA-7500
Cond. 8.5

(Cons. M.H.)
SOLD 3/17/19
SHIPPED TO STEVE IN CONNECTICUT
 


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

 

    

               NEW LISTING 12/18/18
 (Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes)  warranty
VINTAGE & FULLY SERVICED WITH WARRANTY
KENWOOD PRE-AMP / CONTROL AMPLIFIER
KENWOOD BASIC C-1

#...0534
  
Circa '84
Made in Japan

SOLD 2/28/19
SHIPPED TO MARK IN CALIFORNIA

ü Our technician has completely gone through this unit.

ü We have completely gone through this unit, cleaning inside and out including all contacts, switches and controls.

ü Unit All RCA I/O jack terminal solder joints re-flowed internally





ü Unit cosmetically detailed, but does have a few scratches on the metal case /cover

ü All functions tested for perfect operation.

ü All inputs tested fine following I/O re-flow operation

ü Both sides produce clean and even sine waves!

ü No power supply hum of any kind. It's dead silent! 
  ____________________________
  
  
Great 'utilitarian' pre-amp (in fact, while waiting 4 years for two missing knobs to show up, we've been using it here on a number of systems so I'm VERY familiar with it). GREAT sounding as well. Check out the 108dB S/N!!!
Kenwood C-1 Pre-amp / control center. 

  
Kenwood C-1 Features include:
  
- Separate Bass and Treble Controls
- Variable Loudness (Not just a push switch for On / Off)
- Dual tape monitors with A>B dubbing
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- AUX / CD
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input
(may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Phono / Turntable input with Built-In Phono Pre-Amp
- Selector for MM or MC cartridges as it has a built-in Moving Coil Head Amp (that's worth the 'price of admission' if you need it)
- Subsonic filter for reducing turntable rumble / feedback

- Loudness
- Indicator LED's for input selector
- 3 AC outlets ( 2 switched 1 un-switched) for a total capacity of 300 watts

Kenwood C1 Original Specs:
  
 
Design type: 2 Channels, Analog operation
Frequency Response (non-phono input): 1-250kHz +0 / -3dB
Maximum Output Level: 5V

THD Tuner, AUX and Tape, 20-20,000Hz: 0.004% @ 1V output
Signal / Noise Ratio: 108dB!!! @ Tuner, Aux, Tape A/B inputs
Input Sensitivity AUX / Tape @ RCA's: 150mV @ 47k Ω @ 1kHz for rated output

Output AUX / Tape @ RCA's: 150mV @ 47k Ω
Subsonic Filter: >-3dB @ 30Hz, 6 dB/Oct
Loudness Control: 0-+9dB continuously variable (-30dB Vol Level)


PHONO SECTION SPECS:
Freq Response: RIAA Standard curve
30Hz-20kHz w/ RIAA deviation of ±0.3dB
S/N: >87dB MM, >70dB MC

THD Phono MM or MC, 20-20,000Hz: 0.005% @ 1V output

Input Sensitivity (nominal) MM: 2.5mV @ 47
Input Sensitivity (nominal) MC: .25mV @ 100Ω
Phono Overload for MM: 200mV yields THD 0.005% @ 1kHz
Phono Overload for MC: 15mV yields THD 0.005% @ 1kHz

  
This is a great control pre-amplifier for if you just need a good 'utilitarian' pre-amp (but with a built-in MC Head Amp). Perfect for basic control of system. Unit looks and sounds great! Unit measures 17.25" wide x 3" tall x 13" deep and weighs 10 lbs unpacked. Includes our standard 90 day limited warranty.
KENWOOD BASIC C-1
Cond. 8.5

SOLD 2/28/19
SHIPPED TO MARK IN CALIFORNIA

 
(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)


 
 
 

    

          NEW LISTING 11/2018
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
FULLY SERVICED / BENCH TESTED
HAFLER STEREO POWER AMPLIFIER
HAFLER 9180
 #...1277
 Circa 19
91-94
SOLD 3/2/19
SHIPPED TO BRIAN IN TEXAS


ü  Our technician has completely gone through and 'Certified' this unit cleaning contacts, controls and pots.

ü  Amp has been cleaned inside and out.

ü  We replaced the AC power input jack.

ü  Internal fuses checked for correct values and function

ü  Bias and DC offset set correctly.

ü  All functions have been tested and pass with flying colors!

Amp designed using Huge Power Supply Transformer and super quality (expensive) filter caps. Externally located, vertically finned heat sink for very efficient and silent, passive cooling of output devices (all amps / receivers should be designed this way). This amplifier is in both great electronic and physical shape. Looks LIKE NEW and sounds fantastic! All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! Following restoration procedures, we burned it in, in the shop at continuous high volume for 8 hours straight and it functioned flawlessly.
Technician's note:
"this amp was final evolution of the DH-220's. VERY good build quality"
   
On our test bench, this unit's (#...1277) amplifiers produced 32+ Volts at 8 Ohms per channel for 128 Watts / channel and 28+ Volts at 4 Ohms per channel for 210 Watts / channel via discrete output transistors (DC out adjusted to less than 9mV per channel. Floor noise < 0.1mVAC. Idle AC current draw @ .86A)
   
Great "general purpose" power amp for a variety of consumer and Pro-Audio applications. Super quiet operation and build quality. We run it's little brother in our main demo system and have for years. Love it!!! Great for full range stereo speakers, Studio Monitors, stage monitors, wedge monitors or running drivers in a Bi-Amp / Tri-Amp system.
For you 'tech-savvy' types, here's an excerpt from the original manual regarding amp architecture and 'Mono-mode',
"
The input stage of the 9180 Amplifier utilizes four low-noise, High-g, JFET’s (high trans-conductance junction field-effect transistors), in a fully complimentary, symmetric configuration. This circuit configuration results in excellent front-end headroom and a simple, straightforward connection to the remainder of the circuitry. The ultra low noise characteristics of the JFET’s virtually eliminates noise “mixing” (inter-modulation) with the music signal, reducing discordant product frequencies known as “noise grain”, or “noise fuzz”.

    The input stage is cascade connected to convert the low voltage input system to the high voltage output system, and “speeds up” the front end for superior bandwidth. The cascade stage is connected to an emitter-follower and current mirror configuration that amplifies the current level about ten times, necessary to drive the biasing string and final output stage driver emitter followers.
    
The final output stage uses multiple lateral MOSFET’s (Metal Oxide Semiconductor Field Effect Transistors): four devices per channel in the 9180. These devices, unlike conventional bipolar transistors, have a negative temperature coefficient, which means that they do not exhibit “thermal runaway”. Thermal runaway is a phenomenon whereby a transistor heats up as it conducts more current, which causes it to get hotter, and conduct more current, and so on, until the device self-destructs. Since MOSFET’s are inherently self-protecting, no sonically degrading, complex circuitry is required to monitor and protect the output devices.
     Furthermore, these lateral MOSFET’s exhibit a very linear input to output transfer function. Their connection in circuits and operating characteristics are very similar to vacuum tubes, which is perhaps responsible for their widely recognized sonic trait of being very “musical” and non-fatiguing.

     Conversion to Mono Mode is accomplished by driving the negative input (feedback point) of the right channel with the output of the left channel. This causes the right channel to mirror exactly the output of the left channel, but 180 degrees out of phase. This creates twice the voltage swing to be available across the two red output binding posts. This simple method of bridging the amplifier (involving only
one resistor) eliminates the costly and sonically degrading invertors circuitry used in other amplifiers."

 

HAFLER 9180 FEATURES:

  

- Stable down to 2 Ohms!
*

- Two Channel or 'Bridged Mono' Operation
- Very Large Area dedicated to heat dissipation via, Vertically mounted, external heat sinks that cover 66% of the rear panel and almost 100% of each side.
- 'Soft Turn-On / Turn-Off' protection against "turn-on / turn-off" transients
- Thermal protection
for amplifier
- Variable Input level controls on front panel
- RCA input signal I/O's, Gold Plated
- Speaker outputs via 5-Way binding / banana posts
- Discrete output transistors
- Huge power transformer and filter capacitors 75V / 15,00
0
μF

  
 Unit looks near new, performs and sounds great!
  
HAFLER 9180 ORIGINAL SPECIFICATIONS / SPECS:
  

-Stable down to 2 Ohms!
(
*in certain circumstances ie: limited times / frequency range /
 power output. We wouldn't recommend constant 2 ohm load personally for very many amps)
Sensitivity (for 105 watts @ 8 Ohms): 1.4 VRMS

THD: 0.005% @ 1kHz, 0.025% @ 8 ohms, 20Hz - 20kHz
Power Bandwidth: 0.3Hz to 116Hz

S/N: >100dB @ 105 Watts @ 8
Ω un-weighted
Slew Rate: 50V / μsec
Damping Factor: >300 to 1k / 8
Ω & >200 to 10k / 8Ω


Input Impedance: 47k ohms unbalanced
Connectors (each channel): Input: RCA. Output: 5-way binding posts
Cooling: Convection (
Vertically mounted, external heat sinks, wrapping nearly 70% of the way around the amp.)
Amplifier Protection: Full thermal
Speaker
Protection: 'Soft Turn-On / Turn-Off'
Power Consumption: 100W @ 'quiescent' and 1200 Watts max
  

Rated Output Power (per channel):
Continuous Average Output Power Both Channels Driven:
8 ohms, 20Hz - 20kHz, 0.025% THD: 105
Watts
  
Again, we have completely gone through the unit cleaning and testing all. On our test bench, both amplifiers produce perfectly clean and symmetrical sine waves at both 8 & 4 ohm loads. Includes an 'e-copy' pdf download of the Hafler 9180 owners / users / instruction / service manual. Measures 17" wide x 12.5 deep x 4" tall and weighs 33 lbs unpacked. Includes our standard 90 day limited warranty.
HAFLER 9180
Cond. 9

SOLD 3/2/19
SHIPPED TO BRIAN IN TEXAS

 
(Cons.) R.R.
 
 
(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
 
 

 
    

NEW LISTING 1/11/19
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE SANSUI STEREO INTEGRATED AMPLIFIER
SANSUI AU-317 / AU317
#...0583

MIJ
"WORLD AC POWER"
Circa 197
8-80 

SOLD 2/28/19
SHIPPED TO MARK IN CALIFORNIA


ü Our technician has completely gone through and 'Certified' this unit.

ü Everything was cleaned inside and out including all switches, controls and contacts. Cleaned and re-lubed all control shafts.

ü Internal fuses checked for correct value / function and replaced where necessary.

ü Solder joints reflowed on all possible high heat and stress points

ü Amplifier section had output bias and DC offset adjusted to spec levels after 10 min warm-up.

ü All functions tested for perfect operation.

ü Following above procedures, unit was cosmetically detailed inside and out.

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours. (Technicians note, "this is a very 'tech friendly & serviceable' amplifier design")
Total tech time 5+ hours.

On our test bench, each internal amplifier of this particular unit, #...0583, produced peak power of 22 Volts per channel at 8 Ohms for 60 Watts per channel and 19 Volts at 4 Ohms for 90 Watts per channel via discrete, TO-3 / Metal Cased output transistors (Sanken 2x 2SA745 & 2x 2SC1403).
AC Idle current at 200mA. Bias set to correct 10.0mVDC. DC offset adjusted to a SUPER LOW 0 mVDC L&R & floor noise > -60dBm.
 
____________________________

 Very classy matte-black, Sansui AU-317 integrated amp. Huge, internal power supply and 'REAL' output transistors for lots of warmth and tone! Great, all-around amp for home or project recording studio.
Sansui AU-317 Features include:
 
- True Discrete Output, Class A/B amplifier
- Speaker selector for A or B, A+B or Off
- Super quality de-tented volume control
- Separate Bass and Treble with high quality de-tented controls
- "Tone By-pass" for the purest signal path

- Loudness control. "Loudness" functions to boost Bass in relationship to Mid frequencies at lower volume levels for a much fuller sound

- Dual tape deck monitors with 'Tape-2' having a DIN as well as RCA I/O's. (Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
 - Phono input with un-filtered input
 - Phono input with subsonic filter built-in to reduce turn-table rumble

- Tuner input (can also be used for ( Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® etc. inputs)
- Built-in High filter for reducing 19 kHz FM pilot tones and tape hiss and AM noise

- AUX Input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Front mounted 1/4" stereo headphone jack
- 1/4" front mounted mic input with Mic Mixing control to combine microphone signal with other input signals. Can you say "Instant Karaoke"?. (be careful with your 'home audio' speakers using an 'open / live' mic or any other 'un-compressed' signals)
- Pre-Amp Out / Power-Amp in loop
- Back panel features full RCA patch bay for all inputs
- Also features "spring-clip"  speaker connectors for A&B
- Triple AC convenience outlets with 2 Switched and 1 un-switched AC outlets for a maximum load of 400 watts of external gear.

- True "WORLD AC POWER"™ allows unit to be operated on 50 or 60 Hz AC and will select voltages from 110v, 120v, 220v and 240 Volts AC input.
 
Sansui AU-317 Specifications:

 
 
Output: Continuous 50 Watts per channel, min. RMS, at 8 Ohms both channels driven, from 20Hz to 20kHz.

Design type: 2 Channels, Integrated Pre /
 Class A/B operation Power Amplifier
Damping Factor: >70@ 20-20kHz into 8Ω

THD: 0.03% at full rated power into 8
Ω w/ 20-20kHz
Power Bandwidth: 20Hz-20kHz
Frequency Response at 1 Watt: DC-200,000Hz

S/N: 110dB for Tuner, Tape and AUX inputs
Bass Control: ±11dB @ 50Hz
Treble Control: ±10dB @ 15kHz
Subsonic Filter: -3dB @ 13Hz & 6dB / Oct
High Filter: -3dB @ 6dB / oct @ 7kHz

Loudness Control: +9dB @ 50Hz & +7dB @ 10kHz (-30dB Vol Level)

Input Sensitivities: Non-Phono inputs = 150mV / 47kΩ
Input Sensitivity Power Amp: 1V / 47kΩ
Tape outputs: 150mV
Pre-Amp
outputs: 1V
M
icrophone Sensitivity Power Amp:
8mV / 47kΩ

PHONO SECTION SPECS:
Freq Response:
20Hz-20kHz w/ RIAA Equalization of ±0.2dB
S/N: >77dB
Input Sensitivity: 2.5mV @ 47
Phono Overload: 200mV but still maintaining 0.008% THD


Again, as stated above, unit has been completely gone through and certified. All functions have been tested and pass with flying colors! No scuffs, scratches, dings or dents. Face and knobs are in beautiful condition. Unit looks NEW and sounds great! Measures 17" wide x 13.25" deep x 4.5" tall and weighs 23 lbs unpacked. Includes our standard 90 day
limited warranty!
SANSUI AU-317
Cond. 8.5+

SOLD 2/28/19
SHIPPED TO MARK IN CALIFORNIA



(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

      

          NEW LISTING 11/2018
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED
VINTAGE SAE
INTEGRATED STEREO AMPLIFIER
SAE TWO A7
#...3533
DUAL PHONOS, DUAL TAPE MONITORS AND EXTERNAL PROCESSOR LOOP

Circa 1976-83
M.I.J.

SOLD 3/6/19
SHIPPED TO BENJAMIN IN NEW MEXICO


ü  Our technician has completely gone through and 'Certified' this unit.

ü  Everything was cleaned inside and out including all switches, controls and contacts.  Cleaned and re-lubed all control shafts.

ü  Internal fuses checked for correct value / function and replaced where necessary.

ü  ‘Multi-Voltage’ switch replaced and correctly set for North American current. 

ü  Solder joints reflowed on all possible high heat and stress points

ü 
Defective 'meter IC' replaced

ü  Amplifier section had output bias and DC offset adjusted to spec levels after 10 min warm-up.

ü  All functions tested for perfect operation.

ü  Following above procedures, unit was cosmetically detailed inside and out.

ü  All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü  Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours.


On our test bench, each internal amplifier of this particular unit, #...3533, produced peak power of 26 Volts per channel at 8 ohms for 84 Watts per channel and 24 Volts at 4 ohms for 144 Watts per channel via discrete output transistors.
AC Idle current at 460mA. Floor noise 0.3mVAC.
 
____________________________

We don't get many SAE components in (other than my 'personal' units). This is a great amp for mid sized audio systems at 70+ Watts per channel. Great for up to 12" woofer systems. Loaded with 'usable' features as well. Looks and sounds great!


SAE TWO A7 Features Include:


- Discrete Output Transistors
- A-B-A+B-& off speaker selector
- 3-Band EQ w/ Separate Bass, Mid and Treble
- Tone Defeat selector for 'purest' signal path if desired
- Super quality de-tented Volume control pot
- Dual tape deck monitors (Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Bi-Directional Tape Dubbing Capability with Source Monitoring
- Dual Phono / Turntable inputs w/ built-in Phono Pre-Amp
- AUX Input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input (can also be used for ( Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® etc. inputs)
- Loudness control. "Loudness" functions to boost Bass in relationship to Mid frequencies at lower volume levels for a much fuller sound

- Built-in Subsonic Filter to eliminate excess rumble from sources such as turntables

- Instant -20db audio level muting
- Pre-Amp out / Power Amp input loop allows you to either inject an additional / external processor between the Pre and Power, or to connect Pre-amp to another power amp, or to connect another pre-amp to the power amp.
- Front mounted 1/4" stereo headphone jack
- One of my favorite aspects, "Easy to use" Speaker Connectors
- Quad AC convenience outlets on rear panel with 2 switched (550 Watts combined) and 2 un-switched (100 Watts) for a total capacity of 650 Watts of accessories.


Original
SAE TWO A7 Specifications:

POWER SPECIFICATIONS:

Power output: 70 WPC min RMS @ 8 Ohms & no more than 0.05% THD @ 20-20kHz
THD:
no more than 0.05% THD @ 20-20kHz at full rated power
Speaker Impedance: 4 Ohms minimum

PRE-AMP SECTION:
Signal / Noise Ratio:  95dB @ Tuner, Aux, Tape A/B inputs
Input Sensitivity AUX / Tape @ RCA's: 150mV @ 47kΩ @ 1kHz for rated output
Main Input @ AUX or TAPE: >4V
Output AUX / Tape @ RCA's: 150mV @ 47kΩ
Bass Control:  ±10dB @ 100Hz
Treble Control:  ±10dB @ 10kHz
Subsonic Filter: >3dB @ 30Hz, 6 dB/Oct
Loudness Control: +8dB @ 100Hz & 6dB @ 10kHz (-30dB Vol Level)

PHONO SECTION SPECS:
Freq Response:
RIAA Standard Curve & ±0.3dB
Signal / Noise Ratio:  74dB
Input Sensitivity: 2.5mV @ 47kΩ @ 1kHz for rated output
Max Input / Overload limit:  >150mV

Again, we have done the previously stated refurbishment / restoration work on this unit to insure its performance, and it gets our full 'Certification'. All functions tested for perfect operation. This unit is in essentially great cosmetic condition! Performs and sounds great! This is a very ‘musical’ sounding amp with lot’s of punch! Includes a pdf, 'e' copy, download of the SAE TWO A7 / A7e service manual if the purchaser desires. Measures 18.4" wide x 5.5" tall x 13.75" deep and weighs an impressive 24 lbs unpacked. Includes our standard 90 day limited warranty.
Cond. 8.5
SAE TWO A7 Integrated Amplifier

SOLD 3/6/19
SHIPPED TO BENJAMIN IN NEW MEXICO



(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

 

         

        NEW ADDITION 11/16/17
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED
VINTAGE ONKYO STEREO INTEGRATED AMPLIFIER
ONKYO A-7040
STEREO INTEGRATED AMP

#...0899
Circa 1979-81

MIJ
SOLD 12/15/18
SHIPPED TO TIM IN INDIANA

ü  Our technician has completely gone through and 'Certified' this unit.

ü  Following both internal and external visual inspection, the entire unit was cleaned out including all contacts, switches and controls. Switches now clean sounding and performing fine.

ü Silicone heat sink compound inspected for ‘suppleness’

ü Output section bias / DC offset adjusted to factory spec.

ü All functions tested for perfect operation.

ü All inputs and functions tested.

ü Both amplifier sides produce clean and even sine waves! No power supply hum of any kind. It's dead silent!

ü Following electronic refurbishing, the entire unit was cosmetically detailed

ü Following restoration procedures, the unit was ran continuously at medium volume, as all our amplifier / receivers are, into a 4 Ohm load with "Loudness" on and both Tone Controls at 10 for 48 hours.

While this amp was originally rated at 50 WPC on our test bench the internal amplifiers of this particular unit, #...0899, produced 25 Volts per channel at 8 Ohms for 78 Watts per channel and 21 Volts at 4 Ohms for 110 Watts
per channel via discrete, outputs (2x Toshiba 2SA1105 & 2x 2SC2580)
Idle current draw .75A
DC out measured following bench service at only 1.2mV!!! on either side
Very quiet with Floor noise measured at 0.0 mVAC.
   
____________________________
   
Great performing and 'classic' looking Onkyo A-7040 Integrated Amplifier. Great unit to provide the heart of a medium to mid-large sized Hi-Fi system. Unit looks, works and sounds great!
Onkyo A-7040 Features include:
  

- Discrete Output, Class A-B Amplifier design 
- Speaker A, B, A+B, Off selector
- Separate Bass and Treble controls featuring high-quality, de-tented controls
- I/O jacks and Speaker output posts feature 'Point to Point' wiring, so connections are 'stress free' on the circuit boards (all gear should be designed like this, but its 'too expensive' for most of the general public now

- Dual tape deck monitors (Tape Monitors can be used with Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Tape Dubbing Capability
- Dual Phono / Turntable inputs
- Tuner input (can also be used for ( Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® etc. inputs)
- Hi filter for reducing tape hiss / electronic hiss & noise- and record static
- Loudness control. "Loudness" functions to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound
- 1/4" stereo headphone jack
- External Speaker protection fuses
- Dual AC Convenience outlets (1 switched and 1 un-switched) with a total capacity of 200 Watts

   
Original Onkyo A-7040 Specifications:
   
Design type: 2 Channel, discrete output, Class A-B
POWER AMP SECTION:
Freq Response of power amp section:
 15Hz-50kHz
Damping factor: 45 @ 8Ω full bandwidth (means VERY TIGHT bass response)
Signal / Noise: 90dB
Cont rated Power: 2x 50 Watts @ 8 Ohms / 1kHz
THD:
0.026% @ 50Watts & 8 Ohms from 20-20kHz

PRE-AMP SECTION:
Signal / Noise:  90dB @ Tuner / Tape 'shorted'
Input Sensitivity Tuner / Tape @ RCA's: 150mV @ 50kΩ
THD: 0.026% at rated ouput
Bass Control:  ±10dB @ 100hz
Treble Control:  ±10dB @ 10khz
Hi-Filter: 6kHz & 6dB/Oct
Loudness Control: +5dB @ 100Hz & +5dB @ 10kHz(-40dB VOL)

PHONO SECTION SPECS:
Freq Response:
20-20kHz ±0.5dB
S/N: >80dB!!!, IHF-A
Input Sensitivity: 2mV @ 50kΩ
Overload limit: 170mV @ 1k w/ 0.026% THD

 

Again, as stated before, our technician has completely refurb'd this Onkyo A-7040 Stereo Integrated amplifier, cleaning and testing all and it gets our full 'Certification'. All functions test perfectly. Great integrated for just about any stereo system from med to medium large speakers. This is a fabulous amp. Sonically superb following our techs work. Very musical. Lots of solid power / punch. Unit looks good and sounds great! Can include a pdf 'e' copy of the Onkyo A-7040 Service Manual if the new owner so desires. Measures 16.5" wide x 15.7" deep x 5" tall and weighs 21 lbs unpacked. Includes our 90 day limited warranty.
Onkyo A-7040 Stereo Integrated amplifier
Condition 8.5

SOLD 12/15/18
SHIPPED TO TIM IN INDIANA

(Cons.) R.R.



We currently have the 'matching' AM/FM Tuner on our 'Stereo Tuners' page




(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

 

    

    
(above left photo of amp with 'matching' tuner.
Sold separately)

NEW LISTING 11/2018
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED
VINTAGE FISHER
INTEGRATED STEREO AMPLIFIER
FISHER "STUDIO STANDARD" CA-7000 SERIES
FROM FISHER 'SYSTEM 7000' RACK
#...5790
WITH 'MIC MIXING'

Circa 1978-79
M.I.J.
SOLD 12/19/18
SHIPPED TO KYLE IN TEXAS

ü Our technician has completely gone through and 'Certified' this unit.

ü Everything was cleaned inside and out including all switches, controls and contacts.  Cleaned and re-lubed all control shafts.

ü Internal and external fuses checked for correct value / function and replaced where necessary.

ü Solder joints reflowed on all possible high heat and stress points

ü Amplifier section had output bias and DC offset adjusted to spec levels after 10 min warm-up.

ü All functions tested for perfect operation.

ü Following above procedures, unit was cosmetically detailed inside and out.

ü  All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü  Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours.

On our test bench, each internal amplifier of this particular unit, #...5790, produced peak power of 21 Volts per channel at 8 ohms for 55 Watts per channel and 17 Volts at 4 ohms for 72 Watts per channel.
AC Idle current at 230mA. Floor noise < -60dBm.
 
____________________________

Great looking, Rack Mount, Silver-face, Fisher Studio-Standard CA-7000 integrated amplifier. This is a great amp for mid sized audio systems at 70+ Watts per channel. Great for up to 12" woofer systems. Loaded with 'usable' features as well. Looks and sounds great!


Fisher Studio-Standard CA-7000 Features Include:


- Dual VU power level meters showing both dB's and Watts
- Externally located, Vertically oriented heat sinks (keeps output 'heat' outside of the amp housing, where it belongs)

- Separate Bass, Mid and Treble featuring high-quality, De-tented pots
- Super quality de-tented Volume control pot
- Separate Tape Monitor (Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Phono / Turntable input w/ built-in Phono Pre-Amp
- AUX Input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input (can also be used for ( Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® etc. inputs)
- Loudness control. "Loudness" functions to boost Bass in relationship to Mid frequencies at lower volume levels for a much fuller sound
- Microphone input with 'Mixing Level' control (be careful with your speakers using an 'open' microphone thru them)
- Range selector for Power Meters
- Externally located amplifier protection fuses

- Front mounted 1/4" stereo headphone jack
- Rack-Mountable Fisher Studio Standard amp for Fisher racks (17.5" wide. This is not 'standard' rack width, which is 19")
- Triple AC convenience outlets on rear panel with 2 switched (100 Watts combined) and 1 un-switched (100 Watts) for a total capacity of 200 Watts of accessories.


Fisher Studio-Standard CA-7000 Specifications:

POWER SPECIFICATIONS:
Power Bandwidth: 15Hz-40kHz
Power output: 42 WPC min RMS @ 8 Ohms & no more than 0.3% THD @ 15-40kHz
THD:
no more than 0.3% THD @ 20-20kHz at full rated power and 0.03% THD @ 10 Watts output
Damping: 40 @ 8 Ohms
Speaker Impedance: 8 Ohms minimum


PRE-AMP SECTION:
Frequency Response: 120Hz-20kHz
Signal / Noise Ratio:  85dB @ Tuner, Aux, Tape A/B inputs
Input Sensitivity AUX / Tape @ RCA's: 150mV @ 35k Ω @ 1kHz for rated output
Output AUX / Tape @ RCA's: 150mV @ 47k Ω
Bass Control:  ±10dB @ 50Hz
Treble Control:  ±10dB @ 20kHz
Loudness Control: +8dB @ 100Hz & 4dB @ 10kHz (-30dB Vol Level)
Microphone Input w/ 600 Ohm mic:
2.5mV/ 6k Ohms

PHONO SECTION SPECS:
Freq Response:
RIAA Standard Curve & ±0.3dB
Signal / Noise Ratio:  75dB
Input Sensitivity: 2.5mV @ 50k Ω @ 1kHz for rated output
RIAA Deviation: RIAA Standard Curve ±0.5dB

Again, we have done the previously stated refurbishment / restoration work on this unit to insure its performance, and it gets our full 'Certification'. All functions tested for perfect operation. This unit is in essentially great cosmetic condition! The only issue worth mentioning is there's some light 'pitting' on the rack handles that is mostly noticeable when you are caring or lifting the unit by the handles. Performs and sounds great! This is a very ‘musical’ sounding amp with lot’s of punch! Includes a pdf, 'e' copy, download of the Fisher Studio-Standard CA-7000  service manual if the purchaser desires. Measures 17.75" wide x 5.5" tall x 11.5" (including rack handles) deep and weighs an impressive 24 lbs unpacked. Includes our standard 90 day limited warranty.
Cond. 8.5
Fisher Studio-Standard CA-7000 Integrated Amplifier
(Cons.) R.R.

SOLD 12/19/18
SHIPPED TO KYLE IN TEXAS



(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

 

    

NEW LISTING 11/2018
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
SERVICED / BENCH TESTED
NHT (NOW HEAR THIS) MONAURAL SUB-WOOFER
POWER AMPLIFIER
NHT SA-3
 #...1346
"WORLD AC POWER"
 Circa 1998

for sale


Our technician has completely gone through and 'Certified' this unit cleaning contacts, controls and pots.

ü  Amp has been cleaned inside and out.

ü  All inputs tested and both side produces clean and even sine waves!

 
ü  All functions have been tested and pass with flying colors!

ü  This amplifier is in both great electronic and physical shape.

ü  No power supply hum of any kind. It's dead silent!

ü  Following restoration procedures, we burned it in, in the shop at continuous high volume for 8 hours straight and it functioned flawlessly.

Looks great and sounds fantastic!
   
On our test bench, this unit's amplifiers produced 37 Volts at 8 Ohms per channel for 170+ Watts / channel and 35 Volts at 4 Ohms  per channel for 305+ Watts / channel via discrete output transistors. (DC offset measured at outputs at 1.1mVDC. Idle AC current draw @ .34A.)
   

Great "Subwoofer" power amp for a variety of consumer and Pro-Audio applications. Super quiet operation and build quality. Class-G architecture, which is great for 'lower frequencies' to get lots of power efficiently.

Externally located (gets the heat outside of the cabinet where it belongs), vertically finned heat sink for very efficient and silent, passive cooling of output devices (all amps / receivers should be designed this way).

 
NHT SA-3 FEATURES:
  

- Class-G (great for 'subwoofer' applications)
-
Built-in Frequency limiter / selectors
Hi-Pass filter selectable 65Hz, 80Hz, 100Hz, 125Hz and 150Hz
(rear panel)
Low Pass Filter continuously variable from
32Hz to 150Hz
(rear panel)
- Phase selectable for
0°, 90°, 180°, & 210° (rear panel)
- Variable Input Level control (front panel)
- Vertically mounted, external heat sinks
- Gold Plated RCA signal I/O's
- While we did test this stable to 4 Ohms, it is likely rated for a min of 6 Ohms as that what it's 'spec' rating is (no minimum rating stated on rear panel)
- Speaker outputs via 3-Way binding / banana posts
- Discrete output transistors
- True "WORLD AC POWER"™ allows unit to be operated on 50 or 60 Hz AC and will select voltages from 110v, 120v, 220v and 240 Volts AC input.


NHT SA-3 ORIGINAL SPECIFICATIONS / SPECS:


System Type: Monaural Class-G Subwoofer Amplifier
Continuous Average Output Power: 250 Watts @ 6 Ohms

THD: 0.03% @
full rated output
  
On our test bench, the amp produce perfectly clean and symmetrical sine waves at both 8 & 4 Ohm loads.
Includes an 'e-copy' pdf download of the NHT SA-2 Owners / users manual.  Measures 17" wide x 14.5 deep x 5.2" tall and weighs 24 lbs unpacked. Includes our standard 90 day limited warranty.
NHT SA-3
Cond. 8.5
ON HOLD FOR SHOP / OWNERS USE 12/21/18
 
Here's a link to an original review of it...

 
(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
 



 

 
 

    

         NEW ADDITION 3/19/18
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / SERVICED
PRE-APPRECIATED KENWOOD POWER AMPLIFIER
KENWOOD KM-206 / KM206 POWER AMP
'Military Market' / PX UNIT

600+ WATT MONSTER!!!
#...0052
Circa 1985-86
MIJ

SOLD 7/26/18
SHIPPED TO MIKE IN WASHINGTON


ü  Our technician has completely gone through and 'Certified' this unit.

ü  Unit bench checked / tested.

ü  Amp has been cleaned inside and out.

ü  Face removed, meter illumination lens removed, cleaned and reattached.

ü  All new panel illumination lamps replaced with new.

ü  All functions have been tested and pass with flying colors!

Amp designed using Huge Power Supply Transformer and oversized, vertical finned heat sink for very efficient and silent, passive cooling of output devices. All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! Following restoration procedures, we burned it in, in the shop at continuous volume for 48 hours straight and it functioned flawlessly.
   

While this amp is originally rated at 150 Watts with both channels driven (310W + 310W "Peak Music Power"), on our test bench, this particular unit's (#...0052) amplifiers produced 38 Volts at 8 Ohms per channel for 180 Watts / channel and 26 Volts at 4 Ohms per channel for 169 Watts / channel via discrete output transistors (2x Sanken 2SA1216 & 2x 2SC2922 / 2274. (Idle AC current draw @ .4A.
Floor noise measured at L= 00.0mVAC and R=00.0mVAC / -60dBm) 
   

Great, later model power amp by Kenwood. Model KM-206. HUGE power output! Excellent for 2-channel (stereo) audio listening or for use in an A/V system. Lots of punch and headroom.
Kenwood KM-206 Features:
   

- 2- Channel stereo operation
- A or B speaker selector via high current relay
- Dual, Vertical, 7-Segment LED Power Output Meters with Dual Position Level Selector
- Built-in Protection circuit
- LED Status indicators
- Front-mounted 1/4" stereo headphone jack
- RCA input jacks
- Dual, vertical finned internal heat sink
- Oversize power supply transformer
- 3 Rear-mounted AC convenience outlets (2 switched and 1 un-switched for a total capacity of 200 Watts)

   
Kenwood KM-206 Original Specs:
 "150 Watts per channel minimum RMS, both channels driven @ 8ohms, 20-20k, with no more than 0.03% THD"
Design type:
2 Channels, AB operation
Damping Factor: >35 @50Hz / 8 ohms
Signal / Noise: 120dB A weighted
Rated RMS Output: 155 Watts per channel, min. RMS, @ 8Ω, both channels driven, from 20Hz to 20kHz.
Music Power 310 Watts + 310 Watts
THD:
0.03% at 'Full Rated Output'  / 8Ω w/ 20-20kHz
0.015% @ half rated power / 8Ω w/ 20-20kHz
0.001% @ half rated power / 8Ω w/ 1kHz
IMD: 0.002% @ rated power / 8Ω
Power Bandwidth: 10Hz-50kHz @ 0.03% THD @ 8Ω
Potential Frequency Response: 5Hz-200kHz
 

Again, as stated before, our technician has completely refurb'd this Kenwood KM-206, stereo Power-Amp, cleaning and testing all and it gets our full 'Certification'. Great 'all around' power amp for about any audio system. We have sold MANY of this series of Kenwood power amps, with never a complaint. Includes an 'e-copy' pdf download of the Kenwood KM-206 owners / users / instruction manual Unit looks, works and sounds great! Unit measures 16.5" wide x 10.5" deep x 4.75" high and weighs 20 lbs unpacked. Includes our standard 90 day limited warranty.
KENWOOD KM-206
Cond. 8.5++

SOLD 7/26/18
SHIPPED TO MIKE IN WASHINGTON

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

    

NEW LISTING 11/2018
(Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
VINTAGE TECHNICS INTEGRATED STEREO AMPLIFIER
TECHNICS SU-V6X
#...
5A161
BIG POWER &

TONS OF INPUTS FOR A 'VINTAGE' UNIT

Circa 1984-86
"WORLD AC POWER"
M.I.J.
SOLD 12/24/18
SHIPPED TO STEVE IN CONNECTICUT


ü Our technician has completely gone through and 'Certified' this unit.

ü Everything was cleaned inside and out including all switches, controls and contacts.  Cleaned and re-lubed all control shafts.

ü Internal fuses checked for correct value / function and replaced where necessary.

ü ‘Multi-Voltage’ switch replaced and correctly set for North American current. 

ü Solder joints reflowed on all possible high heat and stress points

ü Amplifier section had output bias and DC offset adjusted to spec levels after 10 min warm-up.

ü All functions tested for perfect operation.

ü Following above procedures, unit was cosmetically detailed inside and out.

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent!

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours.


On our test bench, each internal amplifier of this particular unit, #...A161, produced peak power of 34 Volts per channel at 8 ohms for 144 Watts per channel and 24 Volts at 4 ohms for 144 Watts per channel via discrete output transistors (2X 2SA1301 & 2X 2SC3280).
AC Idle current at 450mA. Floor noise > -60dB.
 
____________________________

I used to sell Technics integrated amps (and most of their other gear) when this unit was current. This one appears to be designed for the Euro/Asia/Military market as the version I sold here in North America didn't have as many inputs nor the 'impedance switch' if I recall correctly. This is a great amp for mid to larger sized audio systems at 144+ Watts per channel. Great for larger woofer systems as well. Loaded with 'usable' features as well. Works and sounds great!


TECHNICS SU-V6X Features Include:

- Speaker Load Impedance selector on rear panel. This is probably the most important feature of this amp (I wish all amps had this). Allows 100% of the power to be utilized on speakers of only 8-16 Ohms, instead of 50-75% of power, which would be typical of most amps / receivers.
- Technics 'New Class A' amp architecture (reduces 'switching distortion due to output transistors staying on throughout sine-wave)

- Discrete Output Transistors

- Dual 71V / 15,000 uf power supply filter caps
- A (Main) -B (Remote) -A+B-& off speaker selector
- Separate Bass and Treble
- Tone Defeat (Straight DC) selector for 'purest' signal path if desired
- Dual tape deck monitors (Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Phono / Turntable input w/ built-in Phono Pre-Amp
- AUX Input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- Tuner input (can also be used for ( Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® etc. inputs)
- CD Input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- TV / Video 1 Input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)
- TV / Video 2 Input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRIUS® etc.)

- Graphic EQ loop allows you to either inject an additional / external processor without 'chewing up' one of the inputs
- Record Out selector with bi-directional tape dubbing controls. (Separate "Record Out" allows recording from one source while you listen to another) (‘Record Out’ also allows the use of external signal processors, such as EQ’s, to be used with ‘Tape-2’)

- Loudness control. "Loudness" functions to boost Bass in relationship to Mid frequencies at lower volume levels for a much fuller sound

- Built-in Subsonic Filter to eliminate excess rumble from sources such as turntables

- Instant -20dB audio level muting
- Front mounted 1/4" stereo headphone jack
- Triple AC convenience outlets on rear panel with 1 switched 100 Watts and 2 un-switched (100 Watts ea) for a total capacity of 300 Watts of accessories.

-
True "
WORLD AC POWER"™ allows unit to be operated on 50 or 60 Hz AC and will select voltages from 110v, 120v, 220v and 240 Volts AC input.


Original
TECHNICS SU-V6X Specifications:

POWER SPECIFICATIONS:

Rated Power output: 100 WPC min RMS @ 8 Ohms & no more than 0.003% THD and 0.007% @ 4 Ohms and across 20-20kHz
THD:
no more than 0.001% THD @ 20-20kHz at full rated power
SMPTE IMD: no more than 0.007% THD @ 8 Ohms / 20-20kHz at full rated power
Damping Factor: 80 @ 8 Ohms and 40 @ 4 Ohms (TWICE what many amps are rated at!!!
Speaker Impedance: 4 Ohms minimum

PRE-AMP SECTION:
Signal / Noise Ratio:  104dB @  "Line Level' inputs
(IHF '66 standard)
Input Sensitivity @ any 'Line Level' @ RCA's: 150mV @ 18kΩ for rated output
Output Tape Record @ RCA's: 150mV or EQ loop @ 18
Freq Response: 0.7Hz-140kHz -3dB or 20Hz-20kHz -0.2dB
Bass Control:  ±10dB @ 50Hz
Treble Control:  ±10dB @ 20kHz
Subsonic Filter: >3dB @ 30Hz, 6 dB/Oct
Loudness Control: +9dB @ 50Hz & ~6dB @ ~10kHz (-30dB Vol Level)

PHONO SECTION SPECS:
Freq Response:
RIAA Standard Curve & ±0.5dB
Signal / Noise Ratio:  88dB w/ 2.5mV input (IHF '66 standard)
Signal / Noise Ratio:  72dB w/ 250
μV input (IHF '66 standard)
Input Sensitivity MM: 2.5mV @ 47kΩ for rated output
(IHF '66 standard)
Input Sensitivity MC: 0.17mV @ 220 for rated output
(IHF '66 standard)
Max Input / Overload limit MM:  >170-210mV (Frequency dependant)
Max Input / Overload limit MC:  >12-15mV (Frequency dependant)

Again, we have done the previously stated refurbishment / restoration work on this unit to insure its performance, and it gets our full 'Certification'. All functions tested for perfect operation. This unit is in essentially good cosmetic condition. The 'worth mentioning' cosmetic issues would be that the silk screened labels on the 'Input' buttons have partially worn off, so it's a bit difficult to tell at first what buttons do which inputs. Obviously once you got acquainted with their function you would be able to 'work around' that.
Performs and sounds great! This is a very ‘musical’ sounding amp with lot’s of punch!
Includes a pdf, 'e' copy, download of the TECHNICS SU-V6X service manual if the purchaser desires. Measures 16.9" wide x 5.5" tall x 14.9" deep and weighs an impressive 25 lbs unpacked. Includes our standard 90 day limited warranty.
Cond. 8.5
TECHNICS SU-V6X Integrated Amplifier
SOLD 12/24/18
SHIPPED TO STEVE IN CONNECTICUT

(Cons.) R.R.


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

    



        NEW LISTING 3/21/18

 (Click on above thumbnails to enlarge photos)

CheckMarkSmall_web.jpg (792 bytes)  warranty
VINTAGE PIONEER STEREO INTEGRATED AMPLIFIER
PIONEER SA-7800 / SA7800
'BATTLE WORN' COSMETICALLY, BUT
TECHNICALLY, A

NON-SWITCHING, 'CLASS-A LIKE' POWER HOUSE

 #...3645S
Circa 1978-'80
MIJ

SOLD 6/12/18
SHIPPED TO MIKE IN MARYLAND


 
ü  Our technician has completely gone through and 'Certified' this unit.

ü Following ext / int visual inspection entire unit was cleaned inside and out including all contacts, switches and controls.

ü Bias adjusted to correct spec.

ü Meters calibrated per service manual.

ü Switches and controls now clean sounding and performing solidly.

 
ü All functions tested for perfect operation.

ü All inputs tested and both side produces clean and even sine waves!

ü No power supply hum of any kind. It's dead silent!

ü Following electronic refurb, entire unit was cosmetically detailed (as it 'practically' allowed).

Classic brushed aluminum face plate with the original aluminum knobs (volume knob may be a replacement).
This unit does have a few 'battle scars'. Besides the fairly typical 'finish peel', there's some 'clouding' thru the finish on the meter bezel, and some 'light spots' across the face plate that nothing seemed to effect (It's not a 'beauty contest winner' but not 'offensive', see photo collage above). Following 12+ hours of restoration procedures, the unit was ran continuously at medium volume, as all our amplifier / receivers are, into a 4 Ohm load with "Loudness" on and both Tone Controls at 10 for 48 hours.
     
On our test bench the internal amplifiers of this particular unit, #...3645S, produced 26 Volts per channel at 8 ohms for 84 Watts per channel and 23 Volts at 4 ohms for 132 Watts per channel via discrete outputs (2x 2SA1075 & 2x 2SC2525)
Idle current draw .3A.
 DC out measured at <25mV on either side.
Very quiet with Floor noise measured at <00.1mVAC.
    
____________________________
 
Very classy silver face / Blue Florescent power meter integrated amp. Will match great with Pioneer Cassette Decks and Reel to Reel decks utilizing their famous "Blue" meters. 
Barring it's cosmetic blems it's a Great amp for home or project recording studio use.

Pioneer SA-7800 Integrated Amplifier TECHNICAL Features include:

- 'Non-Switching' amp utilizes 'super linear output transistors' with 'high range switching to reduce switching noise distortion associated with many 'Class A-B' amp designs.
This essentially gives you Class-A sonics, but without all the heat of a true Class-A amp design. It however eliminates the 'switching noise' present in many "A-B" designs (spelled out in detail in the original Pioneer SA-7800 sales brochure, compliments of www.hifi-manuals.com )
- 'DC 'Flat' Amp' eliminates capacitors in the signal chain, thus reducing 'lag' in the signal prior to hitting the power amp
- Gold plated Relay contacts in speaker protection circuit designed to last a lifetime (and I can tell you that 'relay contacts' are an 'issue point' on many amps / receivers we service. If they were all 'gold plated' it would certainly save some 'headaches').
- Super thin cut heat-sink fins for more efficient cooling.
- Pure copper leads on many of the board mounted components (these are not easy to source from a manufacturing standpoint typically)

- Tone Controls with a 'true bypass' when in their '12:00 Noon' position (although there's also a 'Tone Defeat' switch).
- Separately fastened RCA I/O jacks with 'point to point' internal connections


Pioneer SA-7800 Integrated Amplifier Features and 'Creature Comforts' include:


- Produces full power into only '8 Ohms' (most amps can only produce their full power potential into 4 Ohms)
- DC surge and Short Circuit protection built-in 
- Classic Pioneer, Dual Blue Florescent power meters
- Speaker selector for A or B, A+B or Off 
- Subsonic filter with 15Hz cut-off built-in for cutting turntable rumble
- Super quality de-tented volume control
- Tone Defeat for purest tone path if so desired
- Separate Bass and Treble with high quality de-tented controls
- Loudness function (boosts EQ on Bass and Treble, while cutting mids for a fuller sound at lower volume levels)
- 'Stereo / Mono' / Reverse Stereo selector
- Dual tape deck monitors (Tape Monitors can be used with Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Bi-Directional Tape Duplication
- Phono / Turntable input w/ 'Built-in' phono pre-amp
- 'Phono Interference Filter' reduces RFI from external sources
- Tuner input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRUS® etc.)
- AUX input (may also be used for Video / CD / DVD / LD / VCR / DAT / MP3 / iPod® / iPhone® / iPod® / iTouch® / iGadget / eReader / MP3 / XM® / SIRUS®, audio mixers, computer sound-cards etc.)
- Front mounted 1/4" stereo headphone jack
- -20dB Audio Muting
- Back panel features full RCA patch bay for all inputs (each 'fastened separately' to the rear panel, and 'point to point' wired internally, instead of being soldered directly to the circuit board, which is always a 'failure point').
- "spring-clip"  speaker connectors for A&B speakers
-
2 Switched and 2 un-switched AC outlets for a maximum load of 400 Watts of external gear.

 
Pioneer SA-7800 Original Specifications:
 
 "
Continuous Power output of 65 Watts per channel, min. @ 8 Ohms from 20Hz to 20kHz @ <0.009%THD or 65 Watts per channel, min. @ 4 Ohms from 20Hz to 20kHz @ <0.009%THD." (15W more than the SA-708 @ 4 Ohms)
 
Design type: 2 Channels, Integrated Pre /
Class AB operation Power Amplifier
Power Output: Continuous power output, 10Hz-50,000Hz:
65W/Ch THD 0.02% @ 8 Ohms
85W/Ch THD 0.03% @ 8 Ohms

Damping Factor: >55 @ 20-20kHz into 8Ω (15 more than the SA-708)
  S/N: 110dB for 'non-phono' inputs (10dB more!!! than the SA-708)
IMD: 0.003% at half rated power into 8Ω w/ 20-20kHz
  Freq Response: 10Hz-50kHz at full rated power
Input Sensitivities 'non-phono' inputs for full rated output: 150mV / 50KΩ via RCA's
Output at Tape Monitors: 150mV via RCA's
Bass Control:  ±10dB @ 100Hz (SA-708 is only 7.5dB cut / boost)
Treble Control:  ±10dB @ 10kHz  (SA-708 is only 7.5dB cut / boost)
  Subsonic Filter:  -6dB / oct @ 15Hz
 Loudness:  +6dB @ 100Hz & +3dB @ 10kHz w/ vol set at -40dB
Input Freq Response range (non phono inputs): 5-100,000Hz

 
Phono Section:

Freq Response: 20Hz-20kHz RIAA EQ
S/N: 87dB
Phono THD: 0.003% @ 1kHz
Phono MM Sensitivity: 2.5mV / 50kHz
 Phono MM Maximum Input Level: 200mV RMS while still maintaining 0.003% THD @ 1kHz

 
Again, as stated before, our technician has completely refurb'd this Pioneer SA-7800 Integrated Stereo Amplifier, cleaning and testing all and it gets our full 'Certification'. Entire unit, including the original brushed aluminum, Face and knobs are in beautiful condition. Unit looks beautiful and sounds great with what the restoration tech called "Gutsy" power & punch! Just FYI, this Pioneer SA-7800 has considerably better specs than it's little brother, the SA-608 / SA-6800 and certainly it's 'alter ego' SA-708,
(check S/N, tone controls and damping factor particularly).
Comes with an 'e' copy / pdf download of the original Pioneer SA-7800 owners / users manual and brochure if purchaser so desires. Measures 16.5" wide x 14.75" deep x 6" tall and weighs 27.5 lbs unpacked. Includes our 90 day limited warranty!
Pioneer SA-7800 INTEGRATED AMP
Cond. 7.5-8 (due to cosmetic blems)

SOLD 6/12/18
SHIPPED TO MIKE IN MARYLAND

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 
 

  

   


**
"(actual as measured)" refers to original test results done by Hirsch-Houck Laboratories upon test release of product when new. Current "aged" specifications / performance may of course vary from that.

 

 

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