LUXMAN vintage audio
Luxman SQ 202 amplifier & WL 212 tuner
This high quality amplifier produced in the early 1970’s. This amp is inside quite similar to the SQ 507x.
Output: 70watts RMS 8 ohm both Channels driven 80watts RMS 8 Ohm Single Channel driven 100 Watts 4 Ohm Single Channel driven.
THD: Below 0.04% 8 Ohm 1 k Hz Below 0.05% 4 Ohm 1 Khz
Intermodulation Distortion: below 0.05% 8 Ohm 70Hz:7k hz= 4:1
Power band width: 5~50khz (within -3db) Frequency response: 10~60khz ( within -1db)
Input sensitivity: 700mv (8Ohm, 50watt) with level control
Input impedance: about 100k Ohms
Residual noise : About 1 mv
Damping Factor: 35 at 8 Ohms, 70 at 16 Ohms
Transistors: 2SD 218 (2) 2SA 649 (2) 2SC959 (6) 2SA 606 (2) 2SC 1000 (43) XA 495C (4)
Diodes: Uo 5 (4) IS1850 (3) DS38B (4)
Rated output voltage Pre-Out : 700mV, Tape out : 110mV
Maximum output Voltage: aprox 5 V
Output Impedance: Pre Out 100ohm; Tape out 100ohm
Frequency response: 20~70KHz within -1db THD below 0.05 Aux 1 kHz
Input sensitivity: Pre out 700mv; Main 50Watt 8 Ohms, Phono-1, Phono-2; 2mV. Aux 1,2,3 110mV. Mic mix 2.5 mV
Input Impedance: Phono- 1 50K Ohms Phono -2 selectable 30K, 50K, 100k ohms. Aux 1,2,3. 100k ohms
Max input Voltage: Phono-1, Phono-2 180 mV Aux-1,3. 5V Aux-2 adjustable level over 5 V
Hum and noise: (s/n ratio) pre out 700mV
Phono-1, Phono-2. 66db, Aux-1,2,3. 80db, Mic mix with Aux-1 66db Weighted ( ihf “A” curve)
Phono-1, Phono-2 81db. Aux-1,2,3. 90 db. Mic mix with Aux-1. 75db
Noise voltage VS input: Phono-1,Phono-2 -120db/V, Aux-1,2,3 -110 db/V, Mix(mix with Aux-1-118db/V Residual Noise: 25uV
Crosstalk: Phono 66db Aux 71db.
Filters: all 12 db/Octave, High Cut 5KHz, 9KHz. Low Cut 30Hz, 80Hz
Loudness control: 50Hz +8.5db with attenuator on +7.5db Attenuator: -18db
right-click on the pictures to download them and show them in better quality.
click here to download the service manual of the Luxman SQ202
You can update the main power supply the common way: replace the 4 diodes for 8 into
2 bridges to separate power supply in two equal sections after the transformer, for each
channel one section and take 4 new capacitors of approx 6800 uF, 2 for each section,
ie. for each channel. Also check all caps in the power sections for the pre-amp.
You can replace all capacitors in the signal path and replace them for HQ polypropylene caps.
You can replace some resistors in the phono stage signal path, for metal film R's to get a quiet phono stage.
Also you can replace the transistors for more modern low noise transistors in the phono stage.
You can replace the final stage power transistors for better quality transistors with higher Ft.
You can replace the drivers of the power amp with BD139/140 and put little cooling heatsinks on them.
These series of "High Quality" audio components soon got legendary of their outstanding quality and excelent sound performance.
Special thanks to Glenn Stewart from Australia and Helmut Geiselbrechtinger from Germany.
© Hans Hilberink - PE1MMK ® & Glenn Stewart & Helmut Geiselbrechtinger - Last update: 30-05-2013.