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

FULLY SERVICED / RESTORED W/ WARRANTY*
VINTAGE STEREO RECEIVERS
SERVICED / RESTORED CLASSICS 


Vintage Stereo Receivers & Used Stereo Receivers for sale that have been Refurbished. Brands / models of Classic / Vintage Stereo Receivers, 'Old-School' / 2-Channel stereo receivers, and Quadraphonic / Quad AM/FM receivers (sometimes referred to as "Radios" and / or "Tuners") such as Kenwood KR, MCS, Pioneer SX / Pioneer SX-1980 for sale, Sansui G, Sony STR, Yamaha CR and Stereo / home audio receivers from the 1960's, 1970's & 1980's.


 

(*UNLESS OTHERWISE LISTED)
 

SERVICED / REFURBISHED / RESTORED
CLASSIC STEREO RECEIVERS. . .  
 

 

SORRY, AS OF 6/22/2021, TUESDAY AFTERNOON, JUST SOLD OUT OF THE ENTIRE BATCH OF 'RECENTLY RESTORED UNITS' :-( 
WILL KEEP LOOKING FOR MORE TO RESTORE.
    

NEW LISTING 6/17/2021
(Click on above thumbnails to enlarge photos) 
CheckMarkSmall_web.jpg (792 bytes) warranty
RESTORED / REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE AND HUGE KENWOOD
STEREO RECEIVER
KENWOOD KR-8010
BIG POWER!
Circa 1978-81
#...1379
MIJ

SOLD 6/19/2021
SHIPPING TO MANUEL IN CALIFORNIA

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

ü
 Everything was cleaned inside and out including all contacts, switches and controls (including the typically 'no-access', 'push' switches).

ü All (7X) dial / meter lamps / bulbs replaced for trouble-free service

ü FM Function and FM Stereo indicator replaced for trouble-free service (#25-995)

ü All question-able and common 'stress point' solder joints re-flowed

ü Bias current adjusted to the correct 40mVDC (had drifted to 20!)

ü Tuner has it's original Sanyo LA1231 and LA1240 IC chips

ü NO 'Black Leg' transistors anywhere inside this one...YEA!!!

ü We also aligned the tuner 'front-end' for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. VERY GOOD TUNER! FM reception incredible, PUNCHY, with GREAT SEPARATION and IMPECCABLY CLEAN!!!

ü Tuner 'Station Indicator / pointer' aligned internally at tuning cap for position accuracy as well

ü Entire unit cleaned / detailed cosmetically inside and out. Receiver looks FABULOUS and NEAR NEW!

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! All functions test fine.

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

You will not be disappointed. Total restoration time investment ~
11 hours.  

ü On our test bench, the internal amplifiers of this Kenwood KR-8010 receiver, #...1379 produced 36 Volts per channel @ 8 Ohms with 1Khz input for 162 Watts and 26+ Volts per channel @ 4 Ohms with 1Khz input for 169 Watts via discrete, TO-3, metal cased outputs (2x NEC 2x 2SB600 & 2x 2SD555).
ü AC Idle current at 500mA
ü DC offset measures to <25mVDC L/R
ü Bias adjusted to correct spec of 40mVDC.
ü Floor noise @ >-60dBm AC either channel.
   ____________________________


Big and Beautiful, Kenwood KR-8010 (aka; KR-8110) receiver. Classic looking, heavy, brushed-aluminum silver face panel with matching knobs / control caps. Bevel cut dial window really finishes off the elegant look of this series. These are SERIOUS receivers and this one has been
'certified' following the refurb by Oak Tree Vintage and is in great condition!!!
 

Kenwood KR-8010 Stereo Receiver Features:
 

Tuner features:
- Weighted flywheel analog "slide-rule" tuning
- 6-Gang Tuning Capacitor  
- Dual Level FM Muting Selector
- Dual analog 'Signal Strength' and 'Tuning' VU meters
- Built-In, Multi-Directional AM 'Stick / Bar' antenna 

Pre-Amp / 'Control Amplifier' features:
- A, B, A+B, & Off speaker selector
- Three-Band EQ w/ Bass, Mid and Super-Treble controls (may eliminate the need for an external EQ on your speakers since it has a 'Mid' control)
- Tone Defeat for purest signal path
- Super quality de-tented Tone and Volume controls
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- 'Scratch-Filter / Hi filter for reducing tape hiss / electronic hiss & noise and record static
- 100Hz Low Filter built-in to reduce turntable and speaker rumble

Kenwood KR-8010 Inputs:
- Dual Phono / turntable input with Built-In Phono Pre-Amp (with original 'shorting plugs' included to insure noise-free, un-used input)
- Dual tape monitors with Tape monitor 'B' also featuring a DIN input as well as the standard RCA I/O's
(Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / i-gadget / 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)
- AUX Input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)
- 1/4", stereo headphone jack

- Triple AC 'Convenience' outlets (1x switched / 2x un-switched) with a total capacity of 400 Watts

Other / Build-Quality:
- Pre-out / Main-in loop (allows feed to an additional / larger power amp, or to 'direct feed' the power-amp in the receiver with another pre-amp or audio mixer)
- Easy 'Serviceable' internal design including solvent access to potentiometers

- Multiple "Protection" systems included; Short Circuit Protection for Speaker outputs, Overload Protection for Speaker outputs if receiver / amplifier is driven beyond it's design parameters, DC Surge Protection,   Main Line fuse protection, and thermal protection

- Voltage regulator heatsinks properly 'bolted' down and not left to free-float on the regulator legs

- Huge, Vertical heatsinks for efficient cooling

 
Original Kenwood KR-8010 Specifications (specs):

"The Kenwood KR-8010 has a continuous power output of 125 Watts per channel min @ 8 Ohms, from 20 hertz to 20,000 hertz with no more than 0.03% THD
 
POWER / PRE AMP SPECIFICATIONS:
Output:
130WPC @ 8 Ohms / 1k & 135WPC @ 4 Ohms / 1kHz
Dynamic Power Output: 360WPC @ 4 Ohms
THD:
0.03% @ rated output but typically <0.02% @ half power and @ 8 Ohms
Freq Response of power amp section:
5-100kHz & power bandwidth of 5-70kHz
IMD utilizing AUX:
same as THD ratings
Hum / Noise Ratio:
120
dB!!! (w/ shorted inputs)
Damping factor: >35 @ 20Hz-20kHz & 8 Ohms
Power Amp Input Level for full output: 1V & 40k Ohms
Tone Control ranges:
Bass:
+/-12dB @ 50Hz
Mid: +/-12dB @ 800Hz
Treble: +/-12dB @ 15kHz
(this is one of the few I see that doesn't center the 'Treble' all the way up at 20k. MUCH more usable centered at 15k!!!)
Subsonic / Hum / Rumble Filter: -10dB / 18KHz, 6dB/octave
Hi-Cut / Scratch Filter: -10dB / 5KHz, 6dB/octave
Loudness Contour w/ vol @ -30dB: +10dB at 100 Hz
Pre-Amp Input Sensitivity at all inputs except phono & mic:
150mV @ 50k Ohms
Pre-Amp Input Sensitivity for mic: 2.0mV @ 50k Ohms
Max Pre-amp
Level Input: 250mV
Pre-amp
Output: 1V / 1k Ohms
Tape Output:
150mV @ 1kHz 300 Ohms via RCA jacks
Pre-Amp S/N @ 'Tape' & 'AUX': 105dB w/ 150mV input


TUNER SPECS FOR FM:
Tuning Range:
88-108mHz
Freq Response:
20-15kHz (limited by FCC regulations)
S/N @ 65dBf:
 >80dB Mono &  >72dB Stereo

Useable Mono RF Sensitivity for 50dB quieting: 14.1dBf / 2.8 μV
Useable Stereo RF Sensitivity for 50dB quieting: 36.3dBf / 36 μV
Useable Sensitivity (IHF):
9.8dBf (1.7μV)
Capture Ratio:
1.0dB
THD @ 65 dBf, Mono:
0.1%
THD @ 65 dBf, , Stereo: 
0.15%
IF Response Ratio
>90dB
Spurious Response Ratio
>105dB

Image
Rejection Ratio>85dB
FM Alternate Channel Selectivity: 
85dB
AM supression
60dB
Stereo Separation:
~30dB @ 100Hz,
>45dB @ 1kHz & ~30dB @ 15kHz

TUNER SPECS FOR AM:
Tuning Range: 520-1650kHz
Useable Sensitivity (IHF): 250μV/m
Image Response Ratio:
50dB
Signal to Noise Ratio:
50dB
Selectivity:
35dB

PHONO SECTION SPECS:
Freq Response:
RIAA Standard curve +/-0.2dB
S/N:
>84dB, ref w/ 2.5mV input weighted & >90dB, ref w/ 5mV input weighted

Input Sensitivity / Impedance Phono 1&2:
2.5mV @ 50kΩ (what most cartridges typically are going to be)
Overload limit:
250mV RMS @ 1kHz
to not exceed the rated THD of 0.03%

VERY well built


Kenwood receiver, with great features and LOADS OF POWER!

Again, we have completely gone through this Kenwood KR-8010 Stereo Receiver, as stated above and '
certified' it's ready to go!
This is the first Kenwood KR-8010 we've had since one back in 2003!
Cosmetically, other than some scuffs on the tuning knob , the unit is in LIKE NEW condition. Looks like it was unboxed yesterday. Works great and sounds HUGE! Very 'musical' (warm) sounding pre-amp and power amp.
Includes an 'e' copy / pdf download of the Kenwood KR-8010 owners / users / instruction manual. Measures 20.25" wide x 17" deep x 7" high and weighs a
HEAVY 45 lbs unpacked. Includes our standard 90 day limited warranty!
KENWOOD KR-8010 STEREO RECEIVER
Cond. 8.5+

SOLD 6/19/2021
SHIPPING TO MANUEL IN CALIFORNIA

(C) 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 6/8/2021
(click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED
VINTAGE MARANTZ STEREO RECEIVER
MARANTZ 2252
 #...0183
 Circa 1977-78
 Classic 'Blue Face'
 MIJ

SOLD 6/14/2021
SHIPPING TO SCOTT IN MINNESOTA


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

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts. Extensive cleaning of unit internally.

ü Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Previously replaced, and INCORRECT Power switch replaced as well as 'clamping' capacitor as one leg was not letting DC surge protection relay close

ü Power supply circuit adjusted to correct 35VDC output and checked for 'ripple' w/ O-Scope

ü Ungrounded, 2-Prong AC cord replaced with Grounded, heavy-duty, 3-Prong power cord prior to arriving to us

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

ü Internal Power supply circuit adjusted to correct output and checked for 'ripple' w/ O-Scope

ü DC Offset adjusted on both R&L to 0mV+/-0.4mV!

ü Bias adjusted to correct 8mVDC

ü Phono pre-amp originally not working. The tech discovered a burned foil and bad resistor at position R429. Also found transistors; Q405 & Q406 shorted E to B. He replaced ALL 6 transistors in the phono PCB, as well as bad resistors and a couple of electrolytic caps.  


ü We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years.

ü Tuner string checked for any fraying then re-tensioned on Gyro-Wheel to increase traction & relieve flywheel binding and re-centered pointer to correct dial position (after proper tuner, front-end alignment).

ü All dial, "Stereo Indicator", "Dial pointer" & meter lamps 'proactively' replaced (7x Dial & Meter 8V/200mA, 1x Stereo Indicator lamp #25-160 / 8V/35mA and 1x Pointer lamp #25-140 / 8V/70mA)

ü We also checked the heat sink compound which should be good for decades.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

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 72 hours into a 4 Ohm load.

ü Full Cosmetic detail inside and out

Cosmetically the unit is in overall fabulous shape. There's just three or four minor scuffs near the midrange control (see photos above). The balance of the face, knobs and case look good!

On our test bench, this particular Marantz 2252, #...0183 amplifiers each produced 22+ Volts per channel for 60 Watts per channel @ 8 Ω via discrete output & 20+ Volts per channel for 100 Watts per channel @ 8Ω via discrete, "MARANTZ" branded (originals) TO3 Metal Cased outputs (2x 2SA753 & 2x 2SC1343)
AC Idle current at 400mA, DC offset output adjusted to 0mVDC either channel. YES, YOU READ THAT CORRECTLY! "ZERO" mVDC. Bias correctly adjusted to 8mVDC across emitters. Floor noise measured at >-60dBm w/ AUX shorted.)
   ___________________________

   
Classic 'Blue Face' Marantz, 2252 stereo receiver. Elegant looking Face is milled from a solid plank of Aluminum with matching milled aluminum controls. This unit looks great!

Marantz 2252 Features include:

  

- Marantz exclusive "Gyro-Touch" weighted flywheel analog 'Slide Rule' tuning w/ ''PLL' (Phase Locked Loop) circuitry
- A-B, A+B or Off speaker selector
- Separate 'LEFT AND RIGHT' Bass, Mid and Treble utilizing high quality 'Alps' brand pots
- Tone centers selectable for either 100 Hz to 250Hz and 1kHz to 4kHz
- 'Pre-Out' / 'Main-In' loop
 - Built-in Hi filter for reducing 19kHz pilot tone and 38kHz Harmonic in FM broadcasts & Tape hiss.
  - FM muting, separate from FM stereo selector and has adjustable level (on rear panel)
 - Stereo / Mono mode selector for Pre-Amp section or FM tuner (depending on function selected)
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound
 - Phono / turntable  input
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)
- Real 'Tape Monitor Loop' and second 'Tape Input'
  (Tape Monitors can be used with Video / CD / DVD / VCR / DAT / MP3 / iPod® / 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)
- Analog VU 'Tuning' & 'Signal Strength' meter

- Fully shielded tuning capacitor
- Built-In AM 'Stick' antenna
- Antenna attenuator
- 'Quadradial' RCA tuner output (not of much use today)
- 1/4" Stereo Headphone Jack
 - Internally located protection fuse bank
- Separated L & R output heat sink sections featuring large, vertically finned heat sinks
 - Dual AC convenience outlets on rear panel with 1 switched and 1 un-switched for a total capacity of 300 Watts of accessories

  
 Marantz 2252 Stereo Receiver Original Specs:
   "The Marantz 2252 has a continuous power output of 52 Watts per channel @ 8 from 20 hertz to 20,000 hertz with no more than 0.1% THD (measured utilizing AUX input)"
Comparable 'Music' power = 135 Watts
  
POWER / PRE AMP SPECIFICATIONS:
THD:
<0.1% @ 8Ω @ full rated power
Freq Response of power amp section;
 @ full rated power 20-20kHz
Dynamic Range; 96dB
IMD utilizing AUX;
0.1% @
Damping factor: >45 @ 8Ω full bandwidth (FYI; almost twice the damping factor of one of it's 'little brothers' the 2220)
 Input Sensitivity: 180mV for output of 52 Watts @ 8 Ohms
Main Power-Amp in: 1.5V for output of 52 Watts @ 8 Ohms
Input Impedance AUX or Tape: 85k Ohms
S/N AUX:
88dB (3dB more than the 2250)
Pre-Amp
Out Levels; ref. 180mV @ AUX input = 1.5V
ref. 500
mV @ AUX input = 4.2V
Record Out Levels; 180mV
Bass Control;  ±10dB @ 100hz
Mid Control;  ±7.5dB @ 700hz
Treble Control;  ±10dB @ 10khz
Low Filter; 100Hz @ 6dB Oct
High Filter;  7kHz @ 6dB Oct
"Loudness" Contour;  +9dB @ 50hz, +8dB @ 10khz (w/ volume set at -30dB)
 
TUNER SPECS FOR FM:
Freq Response:
30-15kHz (limited by the FCC)
Useable Mono RF Sensitivity for 50dB quieting: 17.3dBf / 4.0 μV
Useable Stereo RF Sensitivity for 50dB quieting: 37.2dBf / 40 μV
Capture Ratio: 1.5dB @ 45dBf
THD w/ 100% modulation @ 1000Hz, Mono: 0.15%
THD w/ 100% modulation @ 1000Hz, Stereo:  0.3%
Spurious Response Rejection: 90dB
Image
Response Rejection: 70dB
I.F. Rejection: 95dB
Alternated Channel Selectivity: 70dB
AM Suppression: w/ 1000
μV = 50dB
19kHz Subcarrier Rejection: 60dB

TUNER SPECS FOR AM;
S/N;
 >49db
Useable Sensitivity; 20μV / m with external antenna
Alternate Channel Selectivity; 46dB
I.F. Rejection; 40dB
Image Response Rejection; 45dB

 
 PHONO SECTION SPECS:

Freq Response:
20-20kHz (typical RIAA is limited to 30Hz to 15kHz)
Input Sensitivity:
1.8 mV @ 47kΩ
Dynamic Range: 96dB!!!
S/N Phono: 7
6dB!!! (typical would be about 68dB and a dB more than the 2250)

Overload:
100mV @ 1kHz
 
 
Again, as stated before, we have completely gone through this Marantz 2252 Stereo Receiver cleaning and testing all and it gets our full
certification. Brushed aluminum face and all original, milled knobs in fabulous shape. After restoration, receiver looks, performs and sounds great! This is a VERY 'Musical' sounding tuner/pre/power-amp. Very 'full, warm and phat'. Great 'low-end' depth at any volume. Tone controls have a lot of influence. Overall a pleasing unit to listen to in all aspects. Measures 17.25" wide x 14.4" deep x 5.5" high and weighs 31 lbs unpacked. Includes our standard 90 day limited warranty!
MARANTZ 2252 STEREO RECEIVER
Cond. 8.5
++
SOLD 6/14/2021
SHIPPING TO SCOTT IN MINNESOTA

(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 6/8/2021
(Click on above thumbnails to enlarge photos) 
CheckMarkSmall_web.jpg (792 bytes) warranty
RESTORED / REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE
CONCEPT STEREO RECEIVER
CONCEPT 5.5 (BY PACIFIC STEREO)
Circa 1978-83
#...7128
MIJ
SOLD 6/21/2021
SHIPPING TO DEAN IN
NEVADA

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

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

ü As we were reassembling the face and knobs, we discovered that the Tuning flywheel was 'stiffining' up (means that it probably have about a dozen revolutions until it would have been completely frozen) so it was removed, bushing was cleaned and re-lubed

ü Fresh, new heat-sink compound applied to output transistors.

ü All dial / meter lamps / bulbs replaced for trouble-free service (4x blue tinted dial)

ü Stereo indicator replaced for trouble-free service (#25-160)

ü Electrolytic power supply filter capacitors replaced with new and upgraded from 10,000 to 12,000uf (originals were working fine, but now it's good for many more years)   

ü All Electrolytic capacitors in the power supply board and both amplifier driver boards (approx 25-30) replaced with new caps (originals were working fine, but now it's good for many more years)

ü All question-able and common 'stress point' solder joints re-flowed

ü All 4 power transistors removed, tested for leakage and fresh, new heat-sink compound applied as well as to pre-drivers

ü Bias current adjusted

ü Tuner has it's original Sanyo LA1230 and LA3550 IC chips

ü NO 'Black Leg' transistors anywhere inside this one...YEA!!!

ü We also aligned the tuner 'front-end' for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. VERY GOOD TUNER! FM reception incredible, PUNCHY, with GREAT SEPARATION and IMPECCABLY CLEAN!!!

ü Tuner 'Station Indicator / pointer' aligned internally at tuning cap for position accuracy as well

ü All push switch LED's working perfectly

ü Entire unit cleaned / detailed cosmetically inside and out. Receiver looks FABULOUS and NEAR NEW!

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! All functions test fine.

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

You will not be disappointed. Total restoration time investment ~
17 hours.  

ü On our test bench, the internal amplifiers of this Concept receiver, #...7128 produced 23 Volts per channel @ 8 Ohms with 1Khz input for 66 Watts and 23.5 Volts per channel @ 4 Ohms with 1Khz input for 138 Watts via discrete, TO-3, metal cased outputs (2x NEC 2SB541 & 2x 2SD388).
ü AC Idle current at 350mA,
ü Bias adjusted to correct spec.
ü Floor noise @ >-60dBm AC either channel.
   ____________________________


Concept was one of four 'house brands' of the huge, West Coast audio chain known as Pacific Stereo. Concepts are highly valued and sought after, and built one of the most sought after of receivers, the HUGE Concept 16.5. This is from that series and is built equally well. For those of you who can appreciate the following, I'll run down the list of impressive features (mostly internal aspects of the unit); 1st; Completely separated / compartmentalized circuits on discrete boards, 2nd; plenty of room to work around different circuit boards, 3rd; components labeled on circuit boards, 4th; quality, industry standard parts populating the boards, 5th; ALPS, full size potentiometers,
  6th; neatly 'loomed' wiring harness, 7th; huge, vertically finned heat-sink, 8th; snubbing caps on each leg of the bridge rectifier, 9th; socketed, TO-3, metal cased outputs, 10th; Point to Point wired I/O components, 11th; fully shielded tuning capacitor, 12th; "In House" and Purpose designed power transformer (not just 'off the shelf')   . Very heavy, high quality build w/ the best parts. I can tell by looking at the internals of Concepts, that they took all the best aspects of most of the other manufacturers of the time, and combined them into one unit. Believe me I've had enough over the past few decades to know that. Shucks, I've had over 120 Pioneer receivers alone!
"The Concept 5.5's power amplifier uses direct-coupled, fully-complementary driver and output stages, with rugged output transistors to increases reliability. These transistors are mounted on extruded aluminum heat sinks for maximum heat dissipation, another measure promoting long transistor life. Two differential gain stages provide the lowest possible distortion at any power level...A slew rate of approx 15V/uSec assures excellent square wave response, even at 10kHz. This slew rate exceeds the minimum required by a 4 to 1 margin...An active protection circuit senses excessive current in the output stages and then disconnects the speakers. This circuit protects the output transistors, and also prevents DC from reaching your speakers and damaging them...Industrial grade speaker switches...Complete internal layout has been carefully designed to reduce hum and minimize any chance for oscillations to develop...Plug-in circuit boards are used to facilitate service..."

Beautiful receiver. Classic looking brushed-aluminum silver face panel with matching knobs / control caps. All encased in a walnut grain, vinyl wrapped, cabinet. These are SERIOUS receivers and this one has been
'certified' following the refurb by Oak Tree Vintage and is in great condition!!!
 

Concept 5.5 Stereo Receiver Features:
 

Tuner features:
- Weighted flywheel analog "slide-rule" tuning
- 'Dual-gate Mos-Fet' circuitry
- 7-Gang Tuning Capacitor    
- Fully Shielded tuner 'Front End'
- FM Muting Selector (separate from the 'Stereo' selector)
- Dual analog 'Signal Strength' and 'Tuning' VU meters
- FM Detector / 4-channel RCA output
- Built-In AM 'Stick / Bar' antenna 

Pre-Amp / 'Control Amplifier' features:
- A, B, C, A+B, A+C, B+C & Off speaker selector (max 2 pair at a time, just with most all receivers / amplifiers to maintain a 4 Ohm minimum)
- Quad-Band EQ w/ Sub-Bass, Bass, Treble and Super-Treble controls
- Tone Defeat for purest signal path
- Super quality de-tented Tone and Volume controls
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- Stereo / Mono selector (for entire pre-amp section, not just FM tuner)
- 'Scratch-Filter / Hi filter for reducing tape hiss / electronic hiss & noise and record static

Concept 5.5 Inputs:
- Phono / turntable input with Built-In Phono Pre-Amp
- Dual tape monitors with Tape monitor 'B' also featuring a DIN input as well as the standard RCA I/O's
(Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / i-gadget / 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)
- AUX (Instead of 1 'Tape Monitor' and 1 "AUX", this unit simply gives you two full-fledged "Tape Monitors", which is essentially an "AUX" with an 'output' as well)
- Dual 1/4", stereo headphone jacks

Other:
- Pre-out / Main-in loop (allows feed to an additional / larger power amp, or to 'direct feed' the power-amp in the receiver with another pre-amp or audio mixer)
- Easy 'Serviceable' internal design
- Multiple "Protection" systems included; Short Circuit Protection for Speaker outputs, Overload Protection for Speaker outputs if receiver / amplifier is driven beyond it's design parameters, DC Surge Protection, Main Line fuse protection.
- Externally located, mains protection fuse
- Dual AC 'Convenience' outlets (1x switched / 1x un-switched) with a total capacity of 200 Watts

- 'Clamping capacitors' on each leg of the bridge rectifier


- Neatly loomed internal wiring throughout
 
Original Concept 5.5 Specifications (specs):

"The Concept 5.5 has a continuous power output of 55 Watts per channel min @ 8 Ohms, from 20 hertz to 20,000 hertz with no more than 0.3% THD and a typical THD @ full power of <0.1% (measured utilizing AUX input)"
 
POWER / PRE AMP SPECIFICATIONS:
THD:
0.3% @ 55 Wpc but typically <0.1% nearly full power and @ 8 Ohms
Freq Response of power amp section:
@ full rated power 20-20kHz
IMD utilizing AUX: 0.1% @ 50Hz

Hum / Noise Ratio:
90dB weighted (4dB better than the "Concept 6.5")
Rise time for 1V p-p:
1.6μsec
Damping factor: >150 @ 20Hz
Power Amp Input Impedance:
20k Ohms
Tone Control ranges:
Bass:
+/-6dB @ 50Hz in 2dB steps
Mid-Bass: +/-10dB @ 100Hz in 1dB steps (this would be the "Bass" control on most gear)
Mid-Treble: +/-10dB @ 10kHz in 1dB steps
(this would be the "Treble" control on most gear)
Treble: +/-6dB @ 20kHz
in 2dB steps
Hi-Cut / Scratch Filter: -10dB  7.5KHz, 6dB/octave
Loudness Contour w/ vol @ -30dB: +8dB at 100 Hz, +4dB at 10KHz
Pre-Amp Input Sensitivity at all inputs except phono:
160mV (a bit more of a buffer than almost everyone else (typical is 150mV) which would reduce the chance of 'over-drive' from sources)
Pre-amp
Output: 950mV
Tape Output:
750mV @ 1kHz, referenced to 100% FM modulation or 10mV of phono
Pre-Amp S/N @ 'Tape' & 'AUX': 85dB
Crosstalk @ 1kHz:
-60dB


TUNER SPECS FOR FM:
Tuning Range:
87.5-109mHz
Freq Response:
30-15kHz (limited by FCC regulations)
S/N:
 >72dB Mono @ 65dBf
Useable Sensitivity (IHF):
9.3dBf (1.6μV)
Capture Ratio:
1.0dB
THD @ 65 dBf, Mono:
0.1%
THD @ 65 dBf, , Stereo: 
0.15%
IF Response Ratio
>95dB
Spurious Response Ratio
>88dB

Image
Response Ratio>90dB
FM Alternate Channel Selectivity: 
85dB
Stereo Separation:
~40dB @ 100Hz, >46dB @ 1kHz & ~38dB @ 10kHz

TUNER SPECS FOR AM:
Tuning Range: 520-1650kHz
Useable Sensitivity (IHF): 175μV/m
Image Response Ratio:
50dB
Signal to Noise Ratio:
40dB

PHONO SECTION SPECS:
Freq Response:
30-15kHz +/-0.2dB to RIAA curve
S/N:
>75dB, ref w/ 10mV input weighted

Input Sensitivity / Impedance Phono:
1.9mV @ 50kΩ
Overload limit:
120mV RMS @ 1kHz


This is one of the BEST BUILT pieces of vintage electronics we've had the pleasure to work on. I can't say enough about it. Concept has now become one of my TOP favorite brands (it was before, this one just drove the point home).
Again, we have completely gone through this Concept 5.5 Stereo Receiver, as stated above and '
certified' it's ready to go!
This is the first Concept 5.5 we've had in almost 24 years of having the website.
Cosmetically the unit is in LIKE NEW condition. Looks like it was unboxed yesterday. You'd have to look pretty close to find any cosmetic issues (I didn't find any). Unit looks near new, works great and sounds HUGE! Very 'musical' (warm) sounding pre-amp and power amp.
Includes an 'e' copy / pdf download of the Concept 5.5 owners / users / instruction manual. Measures 20.25" wide x 17" deep x 7" high and weighs a
HEAVY 52 lbs unpacked. Includes our standard 90 day limited warranty!
CONCEPT 5.5 STEREO RECEIVER
Cond. 8.5++++

SOLD 6/21/2021
SHIPPING TO DEAN IN
NEVADA

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

 

 

 

    

NEW LISTING 6/14/2021
(Click on above thumbnails to enlarge photos) 
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED / WARRANTED
PRE-APPRECIATED CARVER STEREO RECEIVER
CARVER "HR-752 RECEIVER"
BIG POWER @ 144 Watts!
"MAGNETIC FIELD
" POWER AMP
with Carver's 'Sonic Holography
' built-in
#...6010
Circa 1989-91

M.I.J.
SOLD 6/22/2021
SHIPPING TO MARDEN IN
OKLAHOMA

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

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

ü Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Controls were 'flooded' w/ 'De-OxId' and are quiet 


ü Bias adjusted to correct 3mVDC

ü DC offset adjusted to LOW levels on either amplifier.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

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 72 hours into a 4 Ohm load.

All inputs tested and both side produces clean and even sine waves into static 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine. Following restoration procedures, the unit was ran 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.

 
ü On our test bench, the internal amplifiers of this Carver HR-752 receiver, #...1639 produced 30.5 Volts per channel @ 8 Ohms with 1Khz input for 116 Watts and 24 Volts per channel @ 4 Ohms with 1Khz input for 144 Watts via discrete, output transistors (2x Toshiba 2SA1302 & 2x 2SC3281 {Same as Carver MXR-6250}).


ü Floor noise measured @ >-60dBm AC either channel.

 

According to the Orion Blue Book, this was one of the last of the classic, Carver receivers. Modernized by digital tuning and fluorescent display. This is a 'POWER HOUSE' and can power medium to large systems. LOADED with inputs as well as listed below. These are very well built units employing Carver's Unique Magnetic Field Amplifier design. Inside features a double shielded power transformer to reduce noise and ALPS brand pots, switches and contacts throughout. Multiple, very high quality, 5% tolerance resistors throughout...
(note: Essentially the same receiver as the Carver HR-722, but with more power and the addition of 'Pre-Amp OUT / Power-Amp IN' jacks and a "B-Spkr Ambiance Circuit". Otherwise both receiver have same features and specs)

Real, discrete output transistors, mounted on super efficient, vertically finned, thin-walled heat-sink....

Speaker outputs are protected by internal automatically resetting relays and output section is thermal protected. Has matching Rack Handles intact. Looks fabulous!!!
(Authors note; "This receiver is one of the best 'feeling' and most "musical sounding" receivers I've used in a long time. The Sonic Holography seems better on this than what comes on my Carver C-1 Pre-Amp"

Carver HR-752 Features include:


- Digital tuning with up to 20 AM & FM presets
- Circuit Boards populated with 'REAL' components (NOT anemic SMD components)
- True, Discrete Amplifier Outputs (NOT STK chips / Darlington packs)
- Sonic Holography Built-In (this was one of Bob Carvers, 'Signature' patents and were expensive when purchase separately. I sold them when new in the 1980's)
- Auto / Manual tuning modes
- Preset Scan plays 5 second samples of each station preset
- A, B, A+B and 'Off' speaker selector
- "B Speaker Ambience" (HR-752 Only) lets you use the "B" set terminals to provide 'rear channel ambience' which is a matrix surround sound effect by combining the L&R to create a 'reverb' type effect
- Fluorescent and LED displays for digital station readouts, Tuning signal strength, Tuning, Station Presets
- 'Subtle' "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
 - Separate Bass, Mid and Treble controls (ie; 3-band EQ)
- Dual TRUE tape monitors (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / i-gadget / 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 'Dubbing' capability
- Video-1 input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
- Video-2 / Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
- CD Direct (bypasses all the tone and Sonic Holography circuitry providing the purest audio signal path) (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
-  Phono / Turntable input with Built-In Phono Pre-Amp
- ¼" stereo headphone jack
- 4 AC convenience outlets (2x switched
200W /  2x un-switched 300W)

Other / Build-Quality:

- Voltage regulators ALL have proper heatsinks 


- Super-Thin, Vertical heatsink vanes for efficient cooling


Carver HR-752 Original Specs:

POWER / PRE AMP SPECIFICATIONS:
THD;
0.05% @ full rated power
Cont rated Power: 2x 100 Watts @ 8 Ohms / 20-20kHz
Hum and Noise; >90dB on AUX / Tape
Input Sensitivity AUX / Tape; ~150mV @ 47
Record Out Levels; ~150mV
Bass Control; ±8dB @ 100hz
Midrange Control; ±6dB @ 1khz
Treble Control; ±7dB @ 10khz
"Loudness" Contour;  approx; +6dB @ 100hz, +3dB @ 10khz (w/ volume set at -40dB)
Pre-
Gain; 16dB
Pre-
Amp Output Imp; 470 Ohms

TUNER SPECS FOR FM:
Tuning Range;
~88-108MHz
Freq Response;
6Hz-15kHz (limited by FCC)
S/N @ 85 dBf; > 78db Stereo
50dB Quieting Sensitivity; (2.8 μV)
Capture Ratio; <3.0dB!!!
THD @ 65dBf Mono @ 1kHz; 0.15%
Stereo Separation; >46dB @ 1kHz
AM Suppression; 62dB

TUNER SPECS FOR AM:
Useable Sensitivity IHF;
500 uV/m with ferrite stick antenna
Image Rejection; >46dB
I.F. Rejection; >65dB
Selectivity; >50dB
THD; <1.2%

PHONO SECTION SPECS:
Freq Response;
20-20kHz RIAA Standard Curve +/- 0.2dB

S/N on MM;
>78dB
Gain; 36dB
Input Sensitivity MM;
2.5 mV @ 50kΩ
Input Capacitance in PF;
150
 Overload limit;
100mV
 

This is a very elegant, versatile and great performing receiver. Again, as stated above, we have completely gone through this unit,  and it performs, sounds and looks great! Overall, this is an impressive and VERY powerful unit. Versatile and easy to use.
 Includes a pdf 'e' download copy of the Carver HR-752 owners / users manual with purchase.
Measures 19" wide x 4.75" tall x 14.5" deep and weighs 21 lbs un-packed. Includes a 90 day limited warranty.
CARVER HR-752
Cond. 8.5+

SOLD 6/22/2021
SHIPPING TO MARDEN IN
OKLAHOMA

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

 

 

 

 

 

    

      

NEW LISTING 6/8/2021
(click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE PIONEER STEREO RECEIVER
PIONEER SX-780 / SX780
WITH REAL EBONY WOOD VENEER CABINET
#...103S
Circa 1978-80
MIJ

SOLD 6/9/2021
SHIPPING TO TURNER IN GEORGIA


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

ü  We have completely gone through this unit cleaning everything including all switches, controls and contacts. Extensive cleaning of unit internally.

ü  Controls were 'flooded' w/ 'De-Ox-Id' and are quiet

ü  Tuning flywheel started to 'freeze-up' near the end of our refurb process (which is becoming more common over the past half dozen years, due to 'varnished lubes'. We disassembled it, cleaned and re-lubed it, then re-installed it. Should be good for another 30-40 years now.
 
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  Still has it's original Darlington, STK-0050 power output packs (NOT THE PROBLEMATIC CHINESE, FAKE KNOCK-OFFS that only "look" like STK-0050 power packs!)

ü  All dial & meter lamps replaced with 'blue tinted' bulbs to retain original look

ü We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. VERY GOOD TUNER! AM seems to be an 'afterthought' on many stereo receivers and component tuners. The AM is above average for a 'stereo receiver' on this Pioneer SX-780, #...241S. 

ü  All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

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 into a 4 ohm load.

ü  Consignor is also one of our main speaker consignors. He commonly re-veneers speakers prior to delivering them to us for re-sale. Prior to bringing this unit in, he veneered the originally, 'vinyl wood grain' (shelf paper) finish that comes on all SX-790's, with real, heavy figured, Ebony wood veneer. He also re-finished the rear, metal vent.

ü  All inputs tested and both side produces clean and even sine waves into static 8 & 4 ohm, 'brick wall' loads! No power supply hum of any kind. It's dead silent! All functions test fine. Following restoration procedures, the unit was ran 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. All functions test perfectly. No issues anywhere.
  
 
On our test bench, each internal amplifier of this particular unit, #...103S produced peak power of 22 Volts at 8 Ohms per channel for 60 Watts / channel and 18 Volts at 4 Ohms per channel for 81 Watts / channel via Darlington / STK-0050 type, output power packs. (DC offset output adjusted to: <12mV on each side. AC draw at idle 0.30A)
  ____________________________
  
The Pioneer SX-780 model has been touted to be the "Most Sold" receiver in consumer electronics history by any manufacturer. 780's are from the 'well traveled', Classic SX-x80 series. Very nice medium-sized receiver with lots of solid power and plenty of features and the typical "killer tuner" from Pioneer. Has that great milled aluminum look with matching knobs. The only cosmetic exception to the front of the unit is a small nick on the lower edge of the face plate. On the rear there's an area that has some finish wear (see photos above). Overall, this receiver looks good, performs perfectly and SOUNDS GREAT!
  
Pioneer SX-780 Features include:
- Weighted flywheel, slide rule analog tuning
- A, B, A+B & speaker Off speaker selector
- Separate Bass and Treble
- Super quality, de-tented tone control pots by Alps brand
- Dual back-lit analog VU Power Level meters
- Analog VU tuning meter
- 15 Hz Low Filter built-in to reduce turn-table and speaker rumble
- 2-position De-emphasis at 25 & 75 m-sec
-FM muting (separate from 'Stereo / Mono' selector
- Dual tape monitors with Tape 1 to Tape 2 dubbing, and Tape 2 having both RCA and DIN 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® / 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)
- Stereo / Mono mode selector (separate from FM Mute function)
 - "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- Phono / Turntable input
- AUX Input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)

- 2 AC outlets (1 switched 1 un-switched) for a total AC current capacity of 400 Watts worth of accessories
  
Pioneer SX-780 Original Specs:
"The SX-780 has a continuous power output of 45 Watts per channel min. @ 8 Ohms from 20 hertz to 20,000 hertz with no more than 0.050% THD, or 45 Watts per channel at 4 Ohms from 20 hertz to 20,000 hertz with no more than 0.080% total harmonic distortion (measured utilizing AUX input)"
 
POWER / PRE AMP SPECIFICATIONS:
 THD;
0.050% @ full rated power
Freq Response of power amp section;
 @ full rated power 20-20kHz
Potential frequency response of power amp section @ 1w; 5-80,000Hz ±0dB
THD utilizing AUX;
0.050% @ full rated power / 20-20kHz
0.030% @ full rated power / 20-20kHz
Damping factor; 30 @ 8Ω full bandwidth
Rated Power; 45 wpc @ 8 Ohms @ 20-20kHz
Hum and Noise;  95dB @ AUX / Tape
76dB @ Phono
Input Sensitivity AUX / Tape; 150mV @ 50kΩ
Tape Output level;  150mV
Bass Control;  +8 dB / -7dB @ 100Hz
Treble Control;  +7 dB / -6dB @ 10kHz
 Low Filter;-6dB /Oct @ 15Hz
"Loudness" Contour;  +6dB @ 100Hz, +3dB @ 10kHz (w/ volume set at -40dB)
 
TUNER SPECS FOR FM;
Freq Response;
30-15kHz
S/N; > 72db Stereo
S/N; > 80db Mono
Useable Mono Sensitivity; 10.3 dBf
Mono Sensitivity; 1.8 μV
Capture Ratio; 1.0dB
De-Emphasis; 25/75 μs
THD Mono;  0.07%
THD Stereo;  0.15%
FM Selectivity; 75dB
Spurious Response Ratio; 65dB
IF Response Ratio; 90dB
AM Suppression Ratio; 50dB
FM separation;  45dB @ 1kHz / 35dB @ 30-15kHz
 
TUNER SPECS FOR AM;
S/N;
 > 50db
Useable Sensitivity; 300μV / m with ferrite stick antenna or 15μV / m with external antenna
Selectivity; 26dB
IF Response Ratio; 40dB
Image Response Ratio; 40dB
 
PHONO SECTION SPECS;
Freq Response;
20-20kHz

S/N;
82 dB, ref w/ 10mV input
Input Sensitivity;
2.5 mV @ 50kΩ
Overload limit;
200 mV
 
This receiver features a very nice design feature in that the output devices are mounted on the bottom side of the heat sinks for less dust build-up which will allow them to run much cooler for a longer life and tighter sound. All internal control pots and switches are super quality ALPS brand. The best brand Pioneer could have picked. Performs wonderfully, looks fabulous and sounds GREAT!!! Pioneer SX-780's are just a great, all-around receiver. Just the right features for most folks, a good, healthy amount of power, wonderful FM and AM tuner, Good 'pre-amp' section, Great feel, etc... Probably why this was the 'most sold' receiver ever. If you're looking for one of these series you won't be disappointed in this one. Includes a pdf 'e' download copy of the Pioneer SX-780 owners / users manual with purchase. Measures 19" wide x 15" deep x 6" high and weighs 25 lbs unpacked. Includes our standard 90 day limited warranty!
PIONEER SX-780 STEREO RECEIVER
COND. 8.5++


SOLD 6/9/2021
SHIPPING TO TURNER IN GEORGIA

(Cons.)
M.R.
 

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


 

 

 

Did you know?
While the company 'Pioneer' was officially established in 1961, the founder was actually developing speakers as early as 1937. In 1962 Pioneer marketed the worlds first 'separate component' stereo system for the home, and in 1975, the worlds first 'component system' for the car. In 1984 they introduced the first CD player for the automotive use (and I was selling it then). Pioneer had many other 'firsts' and continue to be a major 'player' in consumer, professional and industrial electronics.

 

SOME RECEIVERS WE'RE CURRENTLY WORKING ON AS OF 6/22/2021:

NAD 7100
(Just in. Awaiting place on the bench for initial inspections / evaluation)
NIKKO NR-1219
(Didn't make it through initial bench check for multiple, terminal issues)

 

 

 




So, why do the older / 'vintage' receivers and amplifiers sound so much better (for music) than the much more modern and fancier, 'surround sound - '5.1', '7.1', '9 3/4.1' or '8.BR549' A/V receivers? (Part 2)

Cont from Part 1 of; “So, why do the older / 'vintage' receivers and amplifiers sound so much better (for music) than the much more modern and fancier, 'surround sound - 5.1', '7.1',
'9 3/4.1' or '8.BR549' A/V receivers?” (excerpts ‘paraphrased’ from …
So, just as importantly as the ‘technical aspects’ mentioned in “Part 1”, it’s ALL ABOUT THE MONEY, and we consumers want things as ‘cheaply as possible’, right…? Yes, we do, otherwise the market place wouldn’t be flooded with ‘cheeeeeeeeeeeeeeeeeeese’ from China (and from any of the other sources that can ‘make it as cheaply as possible). You say, “hold on a just gohl-darn minuite”, it’s the manufacturers fault, they’re the ones making things so ‘CHEAP’. NO, it’s not their fault. They are simply following consumer demands (who vote with their dollars, by continually spending as little as possible over the past generation++) and have no choice (at least in ‘mainstream goods’) but to produce and supply goods for as little ‘end user cost’ as possible,…”The Race to the Bottom”. Sure, we consumers give ‘lip service’ to terms like “high quality” and “good service”, but in the end, as a whole, we go for the cheapest options (one of the reasons service companies ‘outsource’ customer service to India, is that they can’t afford to pay ‘domestic labor rates’. Why not? Because we consumers want our phone / cable / insurance or whatever as ‘cheaply as possible, and we aren’t willing to pay for any better). Hey, I’ve been guilty of it a few times myself, but have learned the hard way (fortunately fairly early on)  to try and avoid that method of acquiring items and / or choosing service providers.
So, historically stereo manufacturers had to be concerned, primarily with ‘paying themselves’ in the end, when they designed / built / produced something. When mfgs start out to design an item for market, they are usually ‘backing into it’ from a projected retail / end user price point (that was not necessarily as applicable ‘back in the day’, which is how we ended up with ‘monster receivers’ such as the Marantz 2500 & 2600, Pioneer SX-1980, Sansui G-22,000 and G-33,000, Yamaha CR-3020 and a couple of others that escape me). There are many costs associated with bringing an item / model to market and getting it to the point where it can actually be purchased by an end user / consumer. These costs are similar no matter what the item, ie; stereo gear, clothes, tools, food, services, raw materials, or any item or ‘widget’. Some ‘added cost’ items have generally remained a constant as a percentage of the overall final price of an item, over the years, such as ‘raw materials’, payroll, capitol investments, packaging, transportation / shipping etc. However, in recent years, especially where ‘stereo receivers’ are concerned, manufacturers have been adding more and more features. Most of these “features” have little to do with improving the ‘REAL’ sound quality of the unit, and more to do with compatibility with extraneous aspects. We play DVD’s thru them that are encoded with ‘Dolby’, ‘THX’, ‘dbx’, 'DVD', ‘Lucas Sound’, ‘Blu-Ray’, etc. and inputs that mention things like “iPhone”, “Android”, “iPod”, “Apple”, etc. All of those things are ‘licensed’ from their respective trademark owners. Not to mention all of those manufacturers are constantly making changes (they tend to like to call them ‘upgrades’) to their products, which means that any mfg utilizing or including that ‘3rd party’ product as a feature in their product must now employ their engineers to modify their designs to ‘play well with others’. Those licenses cost money, and those costs take away from money that could be available to invest in the ‘sonic quality’ of the stereo unit.
Sonic quality is a sum of many parts, but a few are ‘discrete’ output transistors, instead of ‘chip’ outputs. ‘Metal-Cased / TO-3’ output transistors, instead of simply ‘epoxy-cased’ transistors. Larger power transformers, and larger storage capacitors to both make sure you have the available current to do the output transformers justice, and the ‘storage capacity’ to make sure you have enough power in reserve to produce deep, rich bass notes. Other aspects that add overall quality to a unit are the caliber of the switches, controls, contacts, semiconductors and components, shielding around sensitive circuits, internal wiring quality and connector / connections quality etc. Is the unit designed with ‘full size’ potentiometers, secured to the chassis with metal ‘shaft nuts’, or is it designed utilizing very ‘small body’ (read, “anemic”) potentiometers, with their control shafts simply protruding thru a hole in the front and secured only by their solder joints (which means that every time you touch / manipulate a control, you are ‘flexing / stressing’ the solder joints and circuit board). The same goes for the I/O jacks on the back panel. Throughout the unit, most
modern (most of what has been built in the past 25-30 or so years) electronics are built utilizing ‘SMD’ technology (look it up). While ‘SMD’ tech facilitates automated assembly processes (read, “robots”), keeps weight down (means lower handling and shipping costs), utilizes smaller individual components (again, ‘cheaper’ parts), SMD doesn’t generally lend to the improvement of ‘sonic qualities’. In-fact, it is probably THE BIGGEST CONTRIBUTOR to degraded, ‘analog’ audio quality. It’s great for things like calculators, computers, smart phones, appliances, automotive control devices etc (unless any of those units are expected to sound good). However, better ‘audio quality’ requires ‘better current’ (Amperes / Amps). Better current is generally best handled by traditional, ‘full size’ electronic components (the stuff designed, starting from about the 1920 thru the 1960’s, and generally peaking in designs released about 1977-79...at least as far as consumer hi-fi goes). Components such as ‘real transistors’ (or tubes if you’re so inclined), full size, electrolytic capacitors (bigger is generally better for storage, and that’s one of the main jobs of capacitors), ‘full size’ resistors to handle all that current without ‘melting down’ or going ‘up in smoke’, etc. The main reason that modern gear is able to attempt to accomplish the same tasks (and more) than vintage gear is that they convert the signal from analog to digital on the front end, and only at the ‘last minute’ convert it back to analog at the back end. That comes back to the generation plus old arguments of analog vs digital.
And the beat goes on…


 

 

 

 

Jerry Gahagan, of Oak Tree Enterprises, LLC standing in front of one of a few 'batches' of speakers put together for an 'upper Mid-West' Micro-Brew chain.

 


Did you know?

MCS was marketed in the US, by JCPenney's in the 1970's and '80's and has generally proved to be solidly designed and built gear in the long run (not so much gear past early 1980's). Most MCS (Modular Component Systems) equipment was built by either Matsushita (parent company of Panasonic (founded 1918) and Technics (introduced 1965) or NEC (established 1898-99, originally known as Nippon Electric Company). Both VERY well respected, electronics industry giants. Most of the MCS stereo receivers and amplifiers prove to be fine performers once 'Certified' by a qualified technician. There are a few 'exceptions' and when we encounter one, they don't even make it to the bench, but then, most brands, including Pioneer, Marantz, Sansui, Kenwood, Sony & Yamaha made a handful of 'exceptionally cheaply designed and built' models that we won't bother to refurbish / restore. When I sold either Technics or Panasonic gear new, I knew there was a VERY low chance of that unit coming back with an issue, over many of the other brands I might have had at my disposal. Needless to say, I am a fan of most gear built by Technics / Panasonic and have seen enough of it to know that if I had to place a 'blind-bet' on an 'as-found' unit either being in 'functioning condition' or being close to it, gear built by Matsushita (NEC as well) will be a 'safe bet'.

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


 

 

 


A COUPLE OF 'AS-IS' RECEIVERS.
NORMALLY WE DON'T OFFER UP 'AS-IS' UNITS, BUT WE HAVE LIMITED TECH TIME, AND AS THESE ARE A COUPLE OF FAIRLY 'HIGH PROFILE' / SOUGHT-AFTER RECEIVERS...
 

    

      NEW LISTING 7/23/19
(Click on above thumbnails to enlarge photos)
VINTAGE FISHER STEREO RECEIVER
THE CLASSIC FISHER 450-T
W/ "AUTOSCAN ELECTRONIC TUNING"

Circa 1969
#...3328
MADE IN USA

for sale

AS-IS - One channel not producing as much "Bass / Fullness of tone" as the other channel.

ü Our technician has gone through this unit to a point

ü Most Dial, Meter, Stereo Indicator lamps work currently (one dial lamp out)

ü Noisy pots / controls cleaned to facilitate service

ü Electrolytic power supply filter capacitors tested for leakage

ü A number of electrolytic capacitors changed in the 'audio path', but that made no difference in the tone (no, we didn't do all of them)

ü All 4 power transistors removed, tested for leakage (we actually switched sides to see if that made a difference in tone)

ü DC offset adjusted to low levels.

ü We also aligned the tuner 'front-end' for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. VERY GOOD TUNER! AM reception WAY above average, FM reception incredible, PUNCHY, with GREAT SEPARATION and IMPECCABLY CLEAN!!!

ü Entire unit cleaned cosmetically inside and out (but not detailed). Receiver looks good

ü One channel not producing as much "Bass / Fullness of tone" as the other channel. On the scope, there's noise on the left channel at around 300Hz, which is likely related to the lack of bass.?...

ü Missing one rubber foot (we didn't pursue due to diminished tone)

ü As a 'side note', ALL the original, brushed, anodized, aluminum 'Knob Brites' intact!

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! All functions test fine.

ü Following basic bench check procedures, the unit was run continuously at medium volume, as all our amplifiers / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours and into a 4 Ohm Load!

ü On our test bench, the internal amplifiers of this Fisher 450T receiver, #...3328 produced 21 Volts per channel @ 8 Ohms with 1Khz input for 55 Watts and 15 Volts per channel @ 4 Ohms with 1Khz input for 56 Watts via discrete, TO-3, metal cased, Motorola outputs (2x Motorola 1060 & 2x 2060).
ü AC Idle current at 220 mA
ü Bias adjusted to correct speck
ü DC offset output adjusted down to <10 mV DC either channel.
ü Floor noise @ < 0.1mVAC either channel.
   ____________________________


This is a very sought after model, but unfortunately it is lacking 'low end' response on one side. We pursued it for a few hours, but had 'bigger fish to fry' and we just don't have the tech resources to pursue it further (You can actually get both channels to sound similar by increasing the bass on one, and decreasing the bass on the other (it has separate L & R Tone controls) ) .
The 'Auto-Scan' function does work.

This is the first Fisher 450T we've had in almost 24 years of having the website. We've had it here a few years, but just now decided to sell it with one channel lacking as much bass as the other.
Cosmetically the unit is in overall great condition for being ~45 years old. Again, we really have only done a cursory cosmetic service. Unit looks good works great and sounds great! Includes an 'e' copy / pdf download of the original Fisher 450 owners / users / instruction manual. Measures 15.5" wide x 14.25" deep x 4.5" high and weighs
25 lbs unpacked.
Fisher 450t STEREO RECEIVER
Cosm Cond. 8+
$499. As-Is
(CONS. R.R.)

(Any additional service / restoration work may be undertaken at any time and will be reflected in an adjustment in price.)

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

 

 

 



Did you know?
A SUPER LOW DISTORTION RATING COULD LIKELY BE A BAD THING!...
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 .

  

 


 



So, why do the older / 'vintage' receivers and amplifiers sound so much better (for music) than the much more modern and fancier, 'surround sound - '5.1', '7.1', '9 3/4.1' or '8.BR549' A/V receivers? (PART 1)


 
 Mostly due to Amplifier design and 'Amplification Classes' - All sound is a sinusoidal waveform. It has alternating peaks and valleys. The center point of each wave is the zero, or switching point that separates the positive (top) from the negative (bottom) portion of each wave. When a amplifier operates in 'Class A' , the output tubes or transistors amplify the entire waveform without splitting it into positive and negative halves. In 'Class AB', (used in the majority of classic receiver / amplifier designs), the signal is split into two halves, positive and negative, and each half is sent to a tube or transistor circuit for amplification. Both sides work in tandem, and the two halves are recombined at the output section to reconstruct the whole signal. This technique increases the amount of power that can be applied, but increases distortion.
In many 'modern' A/V and subwoofer amps, 'Class-D' is the dominant design method. Class D operation is essentially a rapidly switching power amplifier. Here the output devices are rapidly switched on and off at least twice for each cycle. Theoretically, since the output devices are either completely on or completely off they do not dissipate any power (heat), greatly increasing efficiency and lowering manufacturing cost thru lesser parts and lighter freight weight. Not musically the best sounding design for listening to standard, 2-channel music (Radio, Vinyl, CD'S, DAT, Tape (not 'crappy' compressed, MP3 formatted files), but popular for 'A/V-Surround-Sound' systems for reproducing 'movie sound tracks' (not too difficult to do from a 'sonic quality standpoint') where slightly elevated levels of distortion are tolerated and for subwoofer use where maximum power is necessary, and slightly elevated levels of distortion are also easily tolerated...Cont in Part 2 (also on this page)

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 .

  

- - -

 

 



Did you know?

What is the difference between a ‘Tuner’ and a ‘Receiver'?

A ‘Tuner’ is the component or aspect of an audio system that receives or ‘Tunes-In’ Radio Stations.
A 2-channel, stereo ‘Receiver’ is really 3 units in one!
It’s a ‘Tuner’ for receiving radio stations. It’s a ‘Pre-Amp / Control-Amp’ for source / input selection & tone / audio signal modification (with likely the phono 'pre-amp / head-amp' built-in). Lastly it’s a ‘Power Amplifier’ to energize your speakers. It's essentially the 'heart' of most audio / stereo systems.
Some manufacturers would silk-screen 'Tuner-Amplifier' on the front of their receivers, but that was / is simply 'marketing' to make it sound as if it's something more complicated. It's still a 'receiver'. Just FYI.

 

 

What is a 'Receiver' and how is it different than a 'Tuner' or an 'Amp'?
The term 'Receiver' refers to a combined unit consisting of at least 3 aspects incorporated into one. The 3 basic units are the AM/FM 'Tuner' or radio, a 'Pre-Amplifier' / 'Control-Amp' and a 'Power-Amplifier' all combined in one 'box'. Originally the general consensus was that 'receivers' did not perform as well as 'separates' and were sonically inferior. While this may have been the case early on, as in the

 

late 1950's to early '60's, technology improved quickly and by the mid-late 60's the arguments for separates over receivers for most 'mid-level' consumer Hi-Fi applications were generally without merit. For 95% of home-audio listeners, a receiver will be more than ample.

 




 

Click here for our Restoration Procedures



 
- -  

 

Jerry Gahagan of OakTreeVintage
Taken in portion of Speaker Audition Room
Vintage Home Audio Speakers from the late 1960's into the 1980's

 

 

-
SOLD ITEMS BELOW

 



 

 
 


CLICK HERE TO SEE OUR ARCHIVE OF
 SOLD RECEIVERS.
 

WE WILL LIKELY GET MORE OF THEM AGAIN!!!

   

          NEW LISTING 10/30/20
(click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
RESTORED / REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE REALISTIC STEREO RECEIVER
 REALISTIC  STA-2000 / STA2000
"BIG POWER OUTPUT!"
200W+/Channel

Orig Cat #31-2075
#...3278
CIRCA 1978
SOLD 1/25/2021
SHIPPING TO BILL IN MASSACHUSETTS


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

ü Amp has been cleaned inside and out. All internal control pots and switches are super quality.

ü All 6 Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Replaced electrolytic capacitors (13 in all) on power supply board

ü DC offset adjusted to VERY LOW levels on either amplifier (check results below).

ü Bias set to spec @ 17.5mVDC across emitter resistors. Nice, even sine waves to both rails up to 26.5VAC.

ü All Dial / Meter  / function / stereo indicator lamps (eleven in all) replaced for trouble free service.

ü We also aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. The tuner works exceptionally well in our warehouse. Picks up both AM and FM bands way above average!!!

ü All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! All functions test fine. 

ü Plexi, Dial window removed and had scuffs / scratches removed

ü Entire unit cosmetically detailed in and out

ü Real, Walnut wood veneer side panels had fresh coat of Lemon oil and look fine.
      
 
While this unit was originally rated at 75 Wpc, on our test bench, this particular unit, #...3278's amplifiers produced 26.5 Volts per channel at 8 Ohms for 87 Watts per channel & 30 Volts at 4 Ohms for 225 Watts per channel via discrete, TO-3, metal-cased output devices. (NEC 2SB539A & 2SD287A) DC adjusted down to <3mV L&R. AC idle current draw .3A. Floor noise measured at <-60dBm.
    ____________________________
    
Up to 1978, this was the pinnacle of Realistic's offerings. The STA-2000. This one also features an exceptional tuner.

The Realistic STA-2000 is internally built with all the attention to detail and quality you hope to get in a 'vintage, Japanese-built' stereo amp. The, TO-3, Metal Cased output transistors are mounted in a large, heat-sink array, vertically oriented with ventilation located directly above and below. To back up the power output transistors is a HUGE power supply transformer,


(taken prior to bench work, thus the 'dust')

with giant 63V / 15,000 uF Filter capacitors. Also, the capacitors are NOT mounted to a circuit board, but are 'clamped' to the metal chassis and then connected via "point-to-point" wiring. All of the rotary potentiometers are quality, 'FULL SIZE' and are NOT mounted to a circuit board, but fastened to the metal chassis and then connected via "point-to-point" wiring (means that when you put pressure on a knob, you're not directly 'flexing / fatiguing' solder joints on the 'main circuit board' {YES, that happens and is commonly an issue with most gear}). High heat resistors 'stand proud' of the circuit boards, to keep avoid 'heat damage'. Speaker connector terminals are mounted separately (not to the 'main board'), are anchored completely to the rear chassis metal, with their own cb that is 'point-to-point' wired to the main circuit board. The RCA I/O jacks are mounted similarly. The benefit of that is that every time you connect / disconnect a Tape deck, Turntable, CD, DVD, MP-3 player, DAT, iPhone / Android or any other device to the unit, you aren't 'flexing / fatiguing' solder joints on the 'main circuit board'. 7-Gang tuning capacitor, has full shielding to reduce RFI with adjustment markings.
Of course, like most 'good' audio, it's circuit boards are built / populated with 'old school, discrete and 'full size' parts (capacitors, diodes, resistors and transistors) with NO, 'Low Wattage / Low current', 'SMD' components.

All the pots, controls and construction quality in general is way above average! It's built like a "brick $h17 house"
 
Realistic STA-2000 Features include:

- Discrete output transistors, featuring Metal Cased, TO-3 devices (best, most expensive way to build an amp)
- 7-Gang Tuning capacitor

- Weighted flywheel analog "slide-rule" tuning with huge and heavy tuning knob and wide scale window
- Classic brushed Aluminum face panel
- Main & Remote speaker selectors
- Oversized volume control featuring high quality de-tented pot
- Separate Bass and Treble controls utilizing high quality de-tented pots that are also Left and Right independent
 - Pre-Amp / Power Amp loop
- FM Muting (separate from Stereo / Mono selector)
- Mono selector (for the entire pre-amp section, not just the tuner and separate from FM muting selector)
 - "Loudness" function to boost Bass in relationship to other frequencies at lower volume levels for a much fuller sound (careful using this as it's approx a 6dB boost!!!)
- Hi / MPX filter for reducing the 19kHz pilot tone and 38kHz harmonic in FM broadcasts
- Phono / Turntable input w/ built-in phono pre-amp
- -20dB Audio Muting
-  Dual AUX Inputs ((may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®, external mixing board, etc.)
)
- Dual Tape monitors with Bi-Directional Dubbing capability ("Tape-1" features both RCA and DIN 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® / i-gadget / 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)
Dubbing can be used with CDR (CD recorders) units)
-  Dual back-lit, analog VU power meters
- Overload, Thermal and DC short protection built-in
- Analog 'Tuning' Meter for both AM and FM
- Front mounted 1/4" stereo headphone jack
- Speaker outputs via typical / standard "bare wire" push clips and redundant RCA type
 - Externally located main AC protection fuse as well as 5 internally located protection fuses for sub-systems
- Dual AC convenience outlets on rear panel with 1 switched and  un-switched totaling 200 Watts capacity

    
Realistic STA-2000 Original Specs:

Frequency Response: 15Hz to 20kHz ± 2dB
Signal/Noise ratio at AUX input: 75dB
Power Band Width: 20-20kHz
THD: <0.25% @ 75 Wpc
Power:
75 Watts per channel
  
PRE-AMP SECTION SPECS;
Freq Response;
20-20kHz
Bass Control Range; ± 10dB @ 100Hz
Treble Control Range; ± 10dB @ 10kHz
Loudness Compensation; + 6dB @ 100Hz
Cross Talk; 65dB
Tape Out Leval; 140mV
  
  
PHONO SECTION SPECS;
Freq Response;
20-20kHz

 S/N;
70 dB
Input Sensitivity;
2.2mV @ 50kΩ
Overload limit;
230mV
  
TUNER SPECS FOR FM;
Freq Response;
30-15kHz
S/N; > 70db Stereo
Mono Sensitivity; 1.7μV
Capture Ratio; 1.5dB
Image Rejection; 80dB
IF Rejection; 80dB

   
Again, we have completely gone through this Realistic STA-2000 Stereo Receiver, as stated above and
'certified' it's 'Ready To Go'! Real Walnut Wood veneer case in fabulous condition as is the milled aluminum face and all original knobs.
 Fabulous performer. Again this receiver looks and sounds great! It's ready to go and ready to ROCK! Receiver measures 20.5" wide x 18" deep x 7" high and weighs 52 lbs unpacked. Includes our standard 90 day limited warranty.
REALISTIC STA-2000
Condition 8.5

SOLD 1/25/2021
SHIPPING TO BILL IN MASSACHUSETTS

 (C) 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 7/23/19
(Click on above thumbnails to enlarge photos)
VINTAGE & BEAUTIFUL FISHER STEREO RECEIVER
THE CLASSIC FISHER 800-T (SAME AS 500-T EXCEPT ALSO HAS AM)
Circa 1969
#...2638
MADE IN USA

AS-IS - "AUTOSCAN" FUNCTION DOES NOT SEEM TO WORK
SOLD 1/22/2021
SHIPPING TO DAVID IN FLORIDA


ü Our technician has gone through this unit to a point

ü All Dial, Meter, Stereo Indicator and 'Beacon' lamps work currently

ü Noisy pots / controls cleaned to facilitate service

ü Electrolytic power supply filter capacitors tested for leakage

ü All question-able and common 'stress point' solder joints re-flowed

ü All 4 power transistors removed, tested for leakage

ü Bias current adjusted to correct levels.

ü DC offset adjusted to super low levels.

ü We also aligned the tuner 'front-end' for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. VERY GOOD TUNER! AM reception WAY above average, FM reception incredible, PUNCHY, with GREAT SEPARATION and IMPECCABLY CLEAN!!!

ü Tuner 'Station Indicator / pointer' should be aligned.

ü Controls and pots should be further cleaned

ü As a 'side note', ALL the original, brushed, anodized, aluminum 'Knob Brites' intact!

ü Entire unit cleaned cosmetically inside and out (but not detailed). Receiver looks good

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! All functions test fine.

ü Following basic bench check procedures, the unit was run continuously at medium volume, as all our amplifiers / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours and into a 4 Ohm Load!

ü On our test bench, the internal amplifiers of this Fisher 800T receiver, #...2638 produced 21 Volts per channel @ 8 Ohms with 1Khz input for 55 Watts and 14 Volts per channel @ 4 Ohms with 1Khz input for 49 Watts via discrete, TO-3, metal cased, Motorola outputs (2x Motorola TR1038-5 & 2x TR1039-5).
ü AC Idle current at 300mA
ü Bias adjusted to correct spec
ü DC offset output adjusted down to 1.5mV DC either channel.
ü Floor noise @ < 2.4mVAC either channel.
   ____________________________


This is a very sought after model, we just don't have the tech resources to pursue the 'Auto-Scan' function, thus didn't invest more time into it on much of it's other aspects as well (however, even if it was working, it's a fairly 'useless' feature (we have a 450T that it does work on. Also, there are Youtube videos that demonstrate it's limited effectiveness even when functioning correctly).
This is the first Fisher 800T we've had in almost 24 years of having the website. We've had it here a few years, but just now decided to sell it with the 'Auto-Scan' not appearing to work correctly.
Cosmetically the unit is in overall great condition for being ~45 years old. Again, we really have only done a cursory cosmetic service. Unit looks good works great and sounds great! Includes an 'e' copy / pdf download of the original Fisher 500T (again, same unit without AM) owners / users / instruction manual, and brochure. Measures 17.5" wide x 14" deep x 6" high and weighs a
HEAVY 35
lbs unpacked.
Fisher 800T STEREO RECEIVER
Cosm Cond. 8+
As-Is
(CONS. R.R.)
SOLD 1/22/2021
SHIPPING TO DAVID IN FLORIDA


(Any additional service / restoration work may be undertaken at any time and will be reflected in an adjustment in price.)

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

 

 

 
    

         NEW LISTING 10/30/20
(click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
RESTORED / REFURBISHED / FULLY SERVICED / WARRANTED
PRE-APPRECIATED CARVER STEREO RECEIVER
CLASSIC CARVER "THE RECEIVER" / MXR-6250
BIG POWER @ 125 Watts!

with Carver's "MAGNETIC FIELD
" POWER AMP
#...2460

Circa 198
9-90
M.I.J.
SOLD 1/12/2021
SHIPPING TO TIM IN ARIZONA


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

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

ü Mains selector correct @ 120V AC

ü Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

ü Corrected tuner settings for North American frequencies, thus clearing up tuner 'hum / noise' and allowing it to register 'correct' frequencies.

ü DC offset adjusted to LOW levels on either amplifier.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

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 72 hours into a 4 Ohm load.

All inputs tested and both side produces clean and even sine waves into static 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine. Following restoration procedures, the unit was ran 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.

 
ü On our test bench, the internal amplifiers of this Carver MXR-6250 receiver, #...2460 produced 38 Volts per channel @ 8 Ohms with 1Khz input for 180 Watts and 30 Volts per channel @ 4 Ohms with 1Khz input for 225 Watts via discrete,output transistors (2x Toshiba 2SA1302 & 2x 2SC3281).

ü Bias adjusted to correct spec

ü DC offset output adjusted and measured down to < 10 mV DC either channel.

ü Floor noise measured @ >-60dBm AC either channel.
 

According to the Orion Blue Book, this is
the last of the classic, Carver receivers. Modernized by digital tuning and fluorescent display. This is a 'POWER HOUSE' and can power medium to large systems. LOADED with inputs as well as listed below. These are very well built units employing Carver's Unique Magnetic Field Amplifier design. Inside features a double shielded power transformer to reduce noise and ALPS brand pots, switches and contacts throughout. Multiple, very high quality, 5% tolerance resistors throughout...



Real, discrete output transistors, mounted on super efficient, vertically finned, thin-walled heat-sink....



Speaker outputs are protected by internal automatically resetting relays and output section is thermal protected.
Last of the units in Carver's 'Classic Pewter' finish before they switched to 'black'. Has matching Rack Handles intact. Looks fabulous!!!

Carver MXR-6250
Features include:
 

- Digital tuning with 6 AM & FM presets
- Circuit Boards populated with 'REAL' components (NOT anemic SMD components)
- True, Discrete Amplifier Outputs (NOT STK chips / Darlington packs)

- Sonic Holography Built-In (this was one of Bob Carvers, 'Signature' patents and were expensive when purchase separately. I sold them when new in the 1980's)

- Auto / Manual tuning modes
- A, B, A+B and 'Off' speaker selector
- Fluorescent and LED displays for digital station readouts, Tuning signal strength, Tuning, Station Presets and dual Power / Watt output meters
- 'Stereo / Mono' selector on Pre-amp

- 'Subtle' "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.

 - Separate Bass, Mid and Treble controls (ie; 3-band EQ)
- FM Multi-Path Noise Filter

- Dual TRUE tape monitors (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / i-gadget / 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 'Dubbing' capability

- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
- Additional, Dual "AUDIO" inputs (called "VIDEO") (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
- Actual Video Input, VCR-2 I/O for 'video' signal, and TV / VIDEO output

-  Phono / Turntable input with Built-In Phono Pre-Amp
- ¼" stereo headphone jack

- 4 AC convenience outlets (2x switched 350W /  2x un-switched 350W)

Carver MXR-6250 Original Specs:

POWER / PRE AMP SPECIFICATIONS:
THD;
0.05% @ full rated power
Cont rated Power: 2x 125 Watts @ 8 Ohms / 20-20kHz

Hum and Noise; >90dB on AUX / Tape
Input Sensitivity AUX / Tape; ~150mV @ 50kΩ
Record Out Levels; ~150mV
Bass Control; ±8dB @ 100hz
Midrange Control; ±6dB @ 1khz
Treble Control; ±8dB @ 10khz
"Loudness" Contour;  approx; +6dB @ 100hz, +3dB @ 10khz (w/ volume set at -40dB)


TUNER SPECS FOR FM:
Tuning Range;
~88-108MHz
Freq Response;
6Hz-15kHz (limited by FCC)
S/N @ 85 dBf; > 78db Stereo
50dB Quieting Sensitivity;
Mono...18.3dBf (4.0 μV)
Stereo...17dBf (4.5
μV)
Capture Ratio; <1.5dB
Alternate Channel Selectivity @ 98mHz (±400kHz); >72dB
IF Rejection; >85dB
Image Rejection; >42dB
THD @ 65dBf Mono @ 1kHz0.2%
THD @ 65dBf Stereo @ 1kHz0.1%
Stereo Separation; >46dB
@ 1kHz
AM Suppression; 62dB


TUNER SPECS FOR AM:
Useable Sensitivity IHF;
500 uV/m with ferrite stick antenna
Image Rejection; >65dB
IF Rejection; >60dB
Selectivity; >20dB
THD; <0.4%


PHONO SECTION SPECS:
Freq Response;
20-20kHz RIAA Standard Curve +/- 0.2dB

S/N on MM;
>90dB
Input Sensitivity MM;
2.5 mV @ 50kΩ
Input Capacitance in PF;
150
 Overload limit; 100mV
 

This is a very elegant, versatile and great performing receiver. Again, as stated above, we have completely gone through this unit,  and it performs, sounds and looks great! Overall, this is an impressive and VERY powerful unit. Versatile and easy to use. Last of Carver's, 'Pewter' Receivers before they switched to 'Black' anodized.
Measures 19" wide x 5.5" tall x 18.2" deep and weighs 30 lbs un-packe
d. Includes a 90 day limited warranty.

CARVER "THE RECEIVER" MXR-6250
Cond. 8.5+

SOLD 1/12/2021
SHIPPING TO TIM IN ARIZONA

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

 
 

 

         

NEW LISTING 1/14/2021

  (Click on above thumbnails to enlarge photos) 
CheckMarkSmall_web.jpg (792 bytes) warranty
RESTORED / REFURBISHED / FULLY SERVICED & WARRANTED
VINTAGE STEREO RECEIVER
YAMAHA CR-220 / CR220 STEREO RECEIVER 
#...1669
circa 1977-'79
MIJ!

SOLD 3/10/2021
SHIPPING TO STEVE IN INDIANNA


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

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts. Extensive cleaning of unit internally.

ü Internal fuses checked for continuity and correct values.

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

ü Tuner string checked for any fraying then re-tensioned to increase traction & relieve flywheel binding

ü We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years and re-centered pointer to correct dial position.

ü Both dial indicator & meter lamps have been recently replaced.

ü We also checked the heat sink compound which should be good for another 30 years.

ü Amplifier section had output bias adjusted to service manual spec levels of on both amplifiers (33mVDC ±3mV).

ü NOW both amplifiers have 'even' clipping on 'plus' and 'minus' rails.

ü DC offset adjusted to LOW levels on all four amplifiers (less than 7mVDC).

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.
Total restoration time investment 5 hours.

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 72 hours into a 4 Ohm load.
 
ü On our test bench, this particular Yamaha CR-220, #...1669, amplifiers each produced 12+ Volts per channel for 18 Watts per channel @ 8Ω via discrete output & 10+ Volts per channel for 25 Watts per channel @ 4Ω via discrete transistors; 2x 2SA771 & 2x 2SK1986.
ü AC draw at idle .22A.
ü DC <7mV either channel.
ü Floor noise measured at >-60dBm / 0.1mVAC
 ___________________________

   
From the original "CR-X20" series that produced ALL the classic receivers from Yamaha! This is from the series that was capped by the most sought after Yamaha receivers (just the other end) the TOPL CR-3020. This is the entry into that line, the Yamaha CR-220. Same Beautiful brushed solid aluminum front panel with analog, slide rule tuning dial, just less (much less) power. All original, Milled, Aluminum Yamaha knobs intact and in near new condition. This is the first one of this model we've had in 24+ years of having the website. Great receiver for 'small-medium', office, project studio or bedroom system.

Yamaha CR-220 Features:
   

- Discrete output transistors
- Weighted flywheel analog AM/FM slide-rule tuning with lighted dial pointer
- Separate Bass & Treble EQ with super quality de-tented controls
- Features Yamaha's own "Variable Loudness Contour" control utilizing high quality de-tented potentiometer 
- Analog 'd'Arsonval' meter for FM tuning and AM signal strength
- FM Muting / Mono selector
- Stereo / Mono selector for entire pre-amp section (separate from FM selector)
- LED Stereo indicators
- Speaker selector for A - B, A+B, or Off
- 'True' Tape Monitor ("True" 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® / i-gadget / 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) Most Yamaha receivers did not offer "true" Tape Monitors (not just a "Tape Input" on a selector). In fact, I don't remember any that did other than this one.
- Phono input with built-in Pre-Amp
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS®  etc.)
- 1/4" Stereo Headphone Jack
- Rear located, full barrier strip for external antenna connections
- Dual AC convenience outlets on rear panel with 1 switched and 1 un-switched for a total capacity of 400 Watts of accessories

  
Original Yamaha CR-220 Specifications:

POWER SPECIFICATIONS:

Power Output;
The Yamaha CR-220 has a continuous RMS power output of 15 Watts per channel min. @ 8 Ohms from 20 hertz to 20,000 hertz with no more than 0.25% THD (measured utilizing AUX input)
THD; 0.25% @ 15W, 20-20kHz
Signal / Noise; 96dB
Potential power bandwidth power amp section; 10-40,000Hz
Damping factor; 40 @ 8Ω / 1kHz

PRE AMP SPECIFICATIONS:
Signal / Noise; >96dB @ AUX / Tape
Input Sensitivity AUX / Tape; 120mV @ 47
Record Out Terminals (RCA); 120mV @ 1
Bass Control; ±14dB / -10dB @ 20Hz
Bass Control Turnover; 350Hz
Treble Control; ±12dB / -10dB @ 20kHz
Treble Control Turnover; 3.5kHz
Loudness Control; Variable
 
TUNER SPECS FOR FM;
Tuning Range;
88-108MHz
Freq Response;
50-10kHz ±0.5dB
30-15kHz ±1dB
Useable Mono Sensitivity / Quieting Characteristics (for 50 dB S/N); 4μV / 17.3dBf
Useable Stereo Sensitivity / Quieting Characteristics (for 50 dB S/N); 50μV / 38.3Bf
S/N @ 65dBf; > 70dB Mono or 65dB Stereo
Capture Ratio @ 65dBf; 1.5dB
THD Mono @ 1kHz; 0.2%
THD Stereo @ 1kHz; 0.3%
Alt Channel Selectivity; 60dB @ 400kHz
Spurious Noise Ratio; 75dB
Image Response Ratio; 50dB
IF Response Ratio; 75dB
AM Suppression ratio; 52dB
Useable Mono Sensitivity / Quieting Characteristics (for 50 dB S/N); 4μV / 17.3dBf
Useable Stereo Sensitivity / Quieting Characteristics (for 50 dB S/N); 50μV / 38.3Bf
Muting Threshold; 5μV / 19.2dBf
Stereo Separation @ 1Hz; 40dB

TUNER SPECS FOR AM;
Tuning Range;
525-1605kHz
S/N @ 80dB / m; >50dB
Useable Sensitivity (IHF Bar Antenna); 18uV/mV
Selectivity; 20dB @ 1kHz
THD; 0.6% @ 80dB / m
Image Response Ratio; 40dB @ 1kHz
Spurious Rejection; 40dB @ 1kHz
 
PHONO SECTION SPECS;
Freq Response;
RIAA deviation; ±0.5dB
S/N MM; >90dB, (for 10mV output / Shorted inputs)
Input Sensitivity MM; 2mV @ 47kΩ
THD MM to Rec Out; 0.05% for 120mV output
Overload limit MM; 110mV @ 1k

 
Again, we have completely gone through this Yamaha CR-220 Stereo Receiver, as stated above and, it's
'certified' and 'Ready To Go'!
Cosmetically, the only issue worth mentioning is that someone scratched in their id info on the rear panel (see photos above). The brushed Aluminum face and knobs are in LIKE NEW condition. The unit looks fabulous, works and sounds great! Includes a pdf, 'e' copy, download of the Yamaha CR-220 owners / users / instruction manual. Receiver measures 17.2" wide x 12.85" deep x 5.75" high and weighs a heavy,
17 lbs unpacked. Includes our standard 90 day limited warranty.
YAMAHA CR-220 STEREO RECEIVER
Cond. 8.5+

SOLD 3/10/2021
SHIPPING TO STEVE IN INDIANNA

 

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

 

 

 

         

        NEW LISTING 10/30/20
(click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
RESTORED / REFURBISHED / FULLY SERVICED

VINTAGE TECHNICS STEREO RECEIVER
TECHNICS SA-5560
"BIG POWER OUTPUT!"
100W+/Channel

 #....B090
Circa 1976-80
MIJ
SOLD 4/14/21
SHIPPING TO KEVIN IN CALIFORNIA


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

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts. Extensive cleaning of unit internally.

ü Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Speaker protection fuses replaced with higher quality units

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

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 We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years.

ü All dial, indicator & meter lamps 'proactively' replaced w/ modified #DE3021 x3

ü We also checked the heat sink compound which should be good for decades.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

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 72 hours into a 4 Ohm load.

On our test bench, this particular Technics SA-5560, #...B090 amplifiers each produced 29 Volts per channel for 105 Watts per channel @ 8 Ω via discrete output & 25 Volts per channel for 156 Watts per channel @ 4Ω via discrete, TO3 Metal Cased outputs (2 each 2SA747A and 2SC1116A)
AC Idle current at 500mA, DC offset output adjusted to <20 mVDC either channel. Bias correctly adjusted to 12mVDC across emitters. Floor noise measured at >-60dBm w/ AUX shorted.)
   ___________________________

   
Impressive & huge Technics SA-5560 Silver-face receiver. It's not only loaded with features, but it's a 'POWER HOUSE'!

This receiver's amplifier was designed and built around probably the MOST PROVEN output transistor complement in 'Classic Hi-Fi History', generally consisting of two each; "2SA747A" and "2SC1116A", TO3, Metal cased outputs. This unit is in with some impressive 'company' as these are the same outputs used in such famous and classic receivers / amplifiers as; Kenwood KR-8050, Kenwood KR-9400, Kenwood KR-10000 III, Kenwood KR-Nine G, Kenwood Eleven-III, Onkyo TX-4500-II, Pioneer  QX-949 / 949A, Pioneer SX-838, Pioneer SX-1010, Sansui 5000X, Sansui 8080, / 8080DB, Sansui 9090 / 9090DB, Sansui AU-710, Sansui AU-717, Sansui AU-11000, Sansui BA-5000, Sansui G-701 / G-7000, Sony STR-7065, Technics SA-5570, Technics SE-9600, Yamaha B-1, Yamaha CR-1000 to name a few!!!

The Technics SA-5560 is internally built with all the attention to detail and quality you hope to get in a 'vintage, Japanese-built' stereo amp. Besides just 'having' the above mentioned output transistors, they're mounted in a MASSIVE, heat-sink array, vertically oriented with ventilation located directly above and below. To back up the power output transistors is a HUGE power supply transformer,


(taken prior to bench work, thus the 'dust')

with giant 63V / 15,000 uF Filter capacitors. All of the rotary potentiometers are quality, 'FULL SIZE'. High heat resistors 'stand proud' of the circuit boards, to keep avoid 'heat damage'. Speaker connector terminals are mounted separately (not to the 'main board'), are anchored completely to the rear chassis metal, with their own cb that is 'point-to-point' wired to the main circuit board. The RCA I/O jacks are mounted similarly. The benefit of that is that every time you connect / disconnect a Tape deck, Turntable, CD, DVD, MP-3 player, DAT, iPhone / Android or any other device to the unit, you aren't 'flexing / fatiguing' solder joints on the 'main circuit board'.
Of course, like most 'good' audio, it's circuit boards are built / populated with 'old school, discrete and 'full size' parts (capacitors, diodes, resistors and transistors) with NO, 'Low Wattage / Low current', 'SMD' components.

Cosmetically the unit is in overall nice shape. There's just a couple of minor scuffs / smudges above the dial window (see photos above). The balance of the face, knobs and case look near new!

Technics SA-5560 Features include:
    

- Weighted flywheel, analog, 'Slide-Rule' tuning
- "Main", "Remote", or "Main+Remote", or "OFF" speaker positions
- Quality, De-Tented Bass and Treble control potentiometers

- Volume control with super quality de-tented pot
- Loudness control for increasing 'rock-n-roll smile' tone curve at lower volumes
- Built-in Hi (Scratch) and Sub filters for reducing 19kHz pilot tone in FM broadcasts, Tape Hiss, AM hiss and the Sub filter for reducing turntable rumble and feedback.
- "Hi-Blend" for FM ('blends' L&R down to a certain frequency. Useful when you have a 'distant' / weak channel the seems 'noisy' or 'flits' between Stereo / Mono)

- FM muting (separate from Stereo / Mono selector)
- Stereo / Mono ("MODE") selector (separate from FM muting selector)
- Aux inputs (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
- Two 'True' Tape Monitors (either One or Two at once)
  (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® / i-gadget / 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)

- Phono / Turntable inputs with built-in phono pre-amp
- Front mounted 1/4" stereo headphone jack

- Dual Analog /
'd'Arsonval' meters for tuning and signal strength
- 'DC Surge' speaker protection relay for ON/OFF sequence
- Externally located Speaker Output / Amplifier protection fuses
- Rear located, full barrier strip for external antenna connections
- Dual AC convenience outlets on rear panel with 1 switched and 1 un-switched for a total capacity of 300 Watts of accessories

Technics SA-5560 Original Specifications:


POWER / PRE AMP SPECIFICATIONS:
THD;
<0.1% @ full rated power @ 20Hz-20kHz. (0.05% @ Half Power)
Power bandwidth of power amp section; 10Hz-40,000Hz -3dB
 IMD utilizing AUX; <0.1% @ full rated power
Damping factor; 55 @ 8Ω full bandwidth (= 'tight bass' response)
Cont rated Power (while not exceeding 0.1% THD):

2x 90 Watts @ 4 Ohms (Both channels driven 20Hz-20,000Hz)
2x 85 Watts @ 8 Ohms (Both channels driven 20Hz-20,000Hz)
2x 108 Watts @ 4 Ohms (Both channels driven 1kHz)
2x 93 Watts @ 8 Ohms (Both channels driven 1kHz)
S/N; >95dB on AUX / Tape
Input Sensitivity AUX / Tape @ 1kHz for rated output; 150mV @ 35
Record Out Levels; 180mV
Bass Control;  ±13dB @ 50hz
Treble Control;  ±12dB @ 10khz
Low Filter; 100Hz @ 6dB Oct
High Filter;  7kHz @ 6dB Oct
"Loudness" Contour;  +9dB @ 50hz, +8dB @ 10khz (w/ volume set at -30dB)


TUNER SPECS FOR FM:
Tuning Range;
88-108MHz
Freq Response;
20-15kHz (limited to 15kHz by FCC)
S/N; > 72db Stereo w/ 1mV input
> 75db Mono w/ 1mV input
Mono Sensitivity; 1.8μV
Capture Ratio; 1.5dB
IF Rejection; >80dB @ 98MHz
Image Rejection; >53dB @ 98MHz
IF / Spurious Noise Ratio; >80dB @ 98MHz
Selectivity; >70dB
THD w/ 100% modulation Mono; 0.15%
THD w/ 100% modulation Stereo; 0.25%
Stereo Separation; >45dB @ 1kHz

TUNER SPECS FOR AM:
Tuning Range;
525-1605kHz
Useable Sensitivity; 260uV/m with ferrite stick antenna
Image Rejection; >47dB/m @ 1kHz
IF Rejection; >40dB/m @ 1kHz
Selectivity; 22dB @ 1kHz

PHONO SECTION SPECS:
Freq Response;
RIAA Standard Curve +/- 0.2dB

S/N for "IHF-A" weighting;
>78 dB!!!
Input Sensitivity Phono-1;
2.5 mV @ 47
Overload limit; 150mV

Max Power consumption;
270 Watts (not including anything powered through 'Convenience Outlets')

 

Again, as stated before, we have completely gone through this Technics SA-5560 Stereo Receiver, cleaning and testing all and it gets our full
'Certification'. Other than the above mentioned scuffs / smudges to the upper face plate, the unit is in fine cosmetic condition! Again, tons of power as we  bench tested at over 100WPC! Functions, performs and sounds great! Measures 19.75" wide x 6" tall x 16.5" deep and weighs 36 lbs unpacked. Includes our standard 90 day limited warranty.
TECHNICS SA-5560 STEREO RECEIVER
Cond. 8.5

(CONS. R.R.)
SOLD 4/14/21
SHIPPING TO KEVIN 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 11/5/16

  (Click on above thumbnails to enlarge photos)
CheckMarkSmall_web.jpg (792 bytes) warranty
RESTORED / REFURBISHED / FULLY SERVICED
VINTAGE
PIONEER STEREO RECEIVER
PIONEER SX-1980 RECEIVER
PIONEER'S FLAGSHIP
THE 'BIGGEST' 'BADDEST' RECEIVER TO EVER COME OUT OF THE PIONEER FACTORY
HUGE POWER AND SIZE!
340+ Watts PER CHANNEL!!!
"NOT FOR THE 'FAINT OF POCKET-BOOK'
"
#...0723
Circa 1978-79
MIJ

SOLD
SHIPPED TO MONTANA


ü Our technician has completely gone through and 'Certified' this unit. Everything was cleaned inside and out including all switches, controls and contacts. Extensive cleaning of unit internally.

ü Power Supply circuit board and both driver boards had all of their 'electrolytic capacitors' replaced (a note on this; prior to replacing the capacitors, we 'dialed the unit in perfectly' for DC offset, Bias and clean output sine waves to beyond rated power. After replacing all the Electrolytics on the power supply circuit board and the amplifier driver boards, the unit was again measured to perfect levels. The old capacitors ALL checked fine, so basically we have baggies of about 50, 35 year old capacitors that are in fine shape. Just FYI.)

      

     


ü Control potentiometers were 'flooded' w/ 'De-OxId' and are quiet (very difficult to do as 'tone' section must be painstakingly removed).

ü ALL Switches were flooded with cleaner with emphasis especially on the always at issue, switches / controls such as the 'Function' selector, 'Tape Monitors', '-20dB Muting', and 'Tone Bypass'.


ü  Internal fuses checked for correct value / function and replaced where necessary (and there were some 'in-correct' values we found).

ü  World AC Power correctly set for North American current.

ü This unit has a tuner based on the other Pioneer models, with a couple of additional circuits. The additional circuits are the 'Quartz Lock' and the 'Fine Tune', both of which are indicated by LED's near the 'Stereo' LED indicator. These two additional circuits are an issue with SX-1980's we've discovered, and escalating the unit to an outside tech firm, did not improve their function. While the unit's tuner sounds great, it will drift after being left on for a few hours. Could be 2 or could be 24, but it will drift and need a slight 'nudge' on the tuning knob to bring it back into station center. Also, the 'Fine Tune' light is on when the station is slightly 'off center', and not when it's perfectly tuned. Both our senior techs and two outside repair shops, 'senior techs' spent 8-10 hours on these two aspects, with no appreciable improvement. The 4th tech discovered that the unit could be put into a mode which defeated the additional circuits (which when left intact caused a very faint, cyclical noise), so now it functions like the tuner on the Pioneer SX-1280, 1080, 980. Sonically the tuner sounds great, pulls in stations fine, has great side band rejection, and great 'Stereo' sound. Only issue is the above mentioned 'drift' after a few straight hours of running.

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

ü  Amplifier section had output bias and DC offset adjusted to spec levels

ü  We bought ALL the remaining AEL-029 dial bulbs from Pioneer a few years ago. These are the original, official 'Stanley 8V' with blue tinting. We purchased a couple dozen and are probably worth their weight in gold. We have not used them on any of our Pioneer restoration, and have been using a fine substitution. We were saving them for a Pioneer SX-1980 to come along. Well, this unit got them. All four dial lamps and meter lamps replaced with ORIGINAL PIONEER AEL-029's. The balance of the light bulbs, including ALL indicator lamps, the dial pointer lamp, Speaker indictors, 'Stereo' indicator, input / function indicators were replaced with new.

ü All 4
power supply filter capacitors independently tested.

ü All inputs tested and both sides produce clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads!

-VERY GOOD FM TUNER!
- FM reception as well great and IMPECCABLY CLEAN!!! All inputs tested and both sides produce clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine. 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 into a 4 Ohm load. Cosmetically, the top, horizontal edge of the face plate has some light / shallow striations running it's length, there's a scuff on the volume knob, and at some point in it's past, the Walnut, wood 'half bonnet' was re-veneered in a lighter shade of walnut (see photos above). Again, overall this is a fabulous receiver. You won't be disappointed. Total restoration time investment between two senior techs ~38 hours.  

ü  On our test bench, the internal amplifiers of this receiver #...0723 produced 45 Volts per channel @ 8 Ohms with 1KHz input for 253 Watts and 37.4 Volts per channel @ 4 Ohms with 1KHz input for 349 Watts via discrete outputs with 1 kHz input.
 AC Idle current @ .7A,
DC balance adjusted to 0 ±3mVDC and DC offset output adjusted to <~30mVDC either channel. Floor noise measured 0mVAC / >60dB either channel.
   ____________________________


The Pioneer SX-1980 Stereo Receiver. This is the first one of these we've had in 19 years. Even as a Pioneer dealer, back in the day, the stores I worked at didn't carry this model as it was generally TOO EXPENSIVE for the market (equaling about 10% of the average persons yearly take-home pay).
Classic looking brushed-aluminum silver face and encased in a real wood Walnut veneer cabinet with solid Walnut wood corner caps. This is the most SERIOUS receiver Pioneer ever marketed and as listed above, this one has been 'certified' following the refurb by Oak Tree Vintage and is in incredible condition!!! 
An interesting note on this one is that the consignor picked it up from a member of the Denver based, 1970's band, 'Sugar Loaf'
(famous for hit's such as "Green Eyed Lady" and "Don't Call Us, We'll Call You"). It was speculated to have been the amp in their practice space.

Pioneer SX-1980 Features:
 

Tuner features:
- Weighted flywheel analog "slide-rule" tuning
- FM Muting Selector (separate from the 'Stereo' selector)
- Dual analog 'Signal Strength' and 'Tuning' VU meters
- FM Multi-Path Detector (handy when installing antenna for best positioning)
- Dual position FM De-emphasis selectable for 25 or 75 msec 

Pre-Amp / 'Control Amplifier' / Power Amp features:
- Direct Coupled (DC) Power Amp architecture
- A or B or C, or A+B or A+C, or Off speaker selector
- Defeat-able 4-control / 2-band EQ. (Bass controls centered at 50 or 100 Hz and Treble @ 10k or 20kHz)
- Super quality de-tented Tone and Volume controls
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- Stereo / Mono selector (for entire pre-amp section, not just FM tuner)
- Hi filter for reducing tape hiss / electronic hiss & noise and record static
- Built-in 'Low' Filter to eliminate excess rumble from sources such as turntables
- Pre-Amp Out / Power-Amp Input / Loop
- Dual analog 'Power' VU meters
- -20dB Audio Muting for instant lowering of volume without adjusting the volume control. Great for ringing phones and cuing a record on your turntable

Inputs:
- Dual Phono / turntable inputs with Built-In Phono Pre-Amp
- Dual tape monitors with standard RCA I/O's (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / i-gadget / 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 for Tape 1 to Tape 2
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
- Microphone input (be very careful with your 'home audio' speakers when inserting a mic into any stereo receiver)
- 1/4", stereo headphone jack
- Dual Phono inputs with phono 2 doubling as the Microphone input
- 4- Position phono cartridge loading selector with settings at 100, 200, 300 or 400pf for fine tuning phono pre-amp
- 3- Position cartridge impedance selector with settings at 10k, 50k, or 100k for fine tuning phono pre-amp
to your cartridge (a must for serious vinyl players)
- 1/4" front mounted Microphone input
- -20db Audio Muting

Other:
 - Pre-out / Main-in loop
 - 3 AC outlets (1 switched / 2 un-switched) for a total capacity of 300 Watts


Original Pioneer SX-1980 Specifications:


  "The Pioneer SX-1080 has a continuous power output of 270 Watts per channel min @ 8 Ohms, from 20 hertz to 20,000 hertz with no more than 0.03% THD (measured utilizing AUX input)"
 
POWER / PRE AMP:

THD:
0.02% @ 135 Wpc @ 8 Ohms & 0.03% @ Full Rated Output @ 8 Ohms
Freq Response of power amp section:
@ full rated power 20-20kHz. @1W it's rated down to 0.006%
Potential frequency response of power amp section @ 1w:
5 Hz to 100 KHz, +0 dB, -3 dB
IMD utilizing AUX: 0.03% @ 270 Wpc 20-20kHz
0.02% @ 135 Wpc 20-20kHz
0.006% @ 1 Wpc 20-20kHz

Hum / Noise (S/N) Ratio: 120dB (10 db greater than the Pioneer SX-1080)
Damping factor:
40 @ 8Ω full bandwidth
Power Amp Input Impedance:
50k Ohms
Power Amp Input Sensitivity for Full Output:
2V (coupled with the 2V output of the pre-amp, has a lot to do with the VERY high S/N listed above)
Tone Control ranges:

Sub Bass: +/-5dB @ 50Hz
Bass:
+/-10dB @ 100Hz
Treble: +/-10dB @ 10kHz
Upper Treble: +/-5dB @ 20kHz
Hi Filter: 6
KHz, 12dB/octave
(most are 6dB/ octave)
Lo / 'Sub' Filter: 15Hz, 12dB/octave (most are 6dB/ octave)
Loudness Contour: + 6dB at 100 Hz, + 3dB at 10KHz at -40dB on volume control
Pre-Amp Input Impedance: 50k Ohms
Pre-Amp Input Sensitivity at all inputs except phono & mic: 150mV
Microphone Input  Sensitivity / Impedance: 7.5mV / 50k Ohms
Input Freq Response (except Phono & Mic): 5-80kHz
Tape Output Impedance: 50kΩ
Tape Output:
150mV

Pre-Amp Output
Level & Impedance: 2V / 1k Ohms (coupled with the 2V input of the power-amp, has a lot to do with the VERY high S/N listed above and double the SX-1080)
Pre-Amp THD @ rated output: <0.01%

TUNER SPECS FOR FM:
Freq Response:
The full 30-15kHz per FCC Regulations
S/N:
 > 85 dB Mono @ 65dBf
S/N: 
> 75 dB Stereo @ 75dBf
Useable Mono RF Sensitivity dBf / μV:
8.7dBf / 1.5μV
Capture Ratio:
1.0dB
Signal for 50dB quieting, Mono dBf / μV:  
11.5dBf / 2.2μV
Signal for 50dB quieting, Stereo dBf / μV:  36dBf / 34μV
De-Emphasis: selectable 25 or 75 μ-sec
THD w/ 100% modulation @ 100Hz, Mono: 
0.05%
THD w/ 100% modulation @ 1kHz, Stereo: 
0.07%
THD w/ 100% modulation @ 6kHz, Mono:  0.02%
IF Response Ratio: 
120dB
(20db greater than the Pioneer SX-1080)
Stereo Sub-Carrier Rejection: 
65dB

AM Carrier Rejection:
60dB
(5db greater than the Pioneer SX-1080)
Spurious Rejection:
120 dB
(30db greater than the Pioneer SX-1080)
Image Response Ratio:
120 dB
(30db greater than the Pioneer SX-1080)
FM Alternate Channel Selectivity: 
80dB
Muting Threshold dBf / μV:
19.2dBf / 5μV
Stereo Separation:
50dB @ 1kHz or 40dB @ 30-15kHz

TUNER SPECS FOR AM:

RF Sensitivity: 300uV/meter or 15uV @ binding posts
Alternate Channel Selectivity:
26dB
IF Response Rejection Ratio:
70dB
(30db greater than the Pioneer SX-1080)
Image Response Rejection Ratio:
70dB
(30db greater than the Pioneer SX-1080)
Signal to Noise Ratio:
55dB
(5db greater than the Pioneer SX-1080)

PHONO SECTION SPECS:
Freq Response:
20-20kHz ±0.2dB
S/N:
87dB, ref 'shorted' input (11dB greater than the PIoneer SX-1080!!!)
Input Sensitivity:
2.5 mV with load selectable 10k, 50k or 100kΩ
Overload limit:
300 mV @ 1kHz w/ THD of 0.03%
Cartridge Load Capacitance: 100,200,300,400pF


Huge power supply in the Pioneer SX-1980 featuring Dual independent, toroidal transformers (in one housing) for a 'TRUE DUAL POWER SUPPLY', followed by 4X 100V / 22,000μF power supply filter caps to feed the huge output transistors.
Again, we have completely gone through the Pioneer SX-1980 Stereo Receiver, as stated above and 'certified' it's ready to go!
The only 'performance' issues would be the previously mentioned tuner LED's in FM mode, and cosmetically, the scuffs on the top, horizontal face edge, the volume knob scuff and the lighter, real wood Walnut cabinet.  Unit looks great and sounds HUGE! This is truly one of the "BIGGEST BOYS" when it comes to CLASSIC STEREO RECEIVERS! Includes a pdf, 'e' copy, download of the Pioneer SX-1980 owners / users / instruction manual, Service manual and original brochure if the purchaser so desires. Measures 22.25" wide x 20" deep x 8.25" high and weighs a HEAVY 73 lbs unpacked. Includes our 90 day limited warranty!
PIONEER SX-1980 STEREO RECEIVER
 Cond. 8.5
$6,300.00
SOLD
SHIPPED TO MONTANA

(Cons.) M.R.

links to a couple of "Shoot Out" articles featuring the SX-1980;


https://www.cnet.com/news/how-can-30-year-old-receivers-sound-better-than-new-ones/

http://www.iavscanada.com/receiver-shoot-out-vintage-vs-high-tech/

(Due to the dimensions and / or weight of this receiver, Packing / Shipping will be somewhat more 'involved' than typical. A custom built box may be necessary to order. While we order custom built boxes often, this can sometimes delay shipping by 5-10 days)

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

 


 



Did you know?
Sansui was founded in 1947, just after WWII as a company manufacturing transformers (one of the most important components of any audio system). During the Sixties they morphed into what would become one of the most well respected companies in quality audio gear. I have owned and sold some incredible Sansui stereo gear from the Seventies and early Eighties. I worked at a Sansui dealer in the early part of the Eighties. Sansui remained a major force in stereo gear until about the mid Eighties, when the vast majority of audio gear started suffering from the 'how cheaply can we get it' syndrome by consumers, thus manufacturers followed suit, by building cheaper and cheaper gear.

 

 

 

Did you know?
It would be hard to name a category of 'musical instruments', 'audio equipment', 'motorized vehicles', or 'sporting equipment' that Yamaha does not have a 'hand in' with 'branded models'. Most folks do not realize this, but Yamaha is one of the oldest companies in existence, certainly when it comes to music gear and was actually established in 1887 and was incorporated on October 12, 1897! The company's origins as a musical instrument manufacturer is still reflected today in the group's logo—a trio of interlocking tuning forks. Yamaha has grown to become the world's largest manufacturer of musical instruments. I have worked for Yamaha dealers over the years, in both the 'consumer' level and 'pro-audio' / 'MI' level. Their gear was 'spec'd' more often in the military contracts we received, than any other brand. I knew when I sold a Yamaha unit, there was little chance of an 'issue after the sale'. Yamaha products are known as having about the best 'resale value' of any brand, regardless of the product class.

 

   
 

 

 


We've moved the "SOLD / ARCHIVED" items to their own page.
Click ........HERE.


 


**
"(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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