Luxman SQ 202 amplifier

General: 

This amplifier produced in the early 1970’s. This amp is inside quite similar to the SQ 505 and 507.

 

Photos:

 

Special futures:

 

Schematic:

      right-click on the pictures to download them and show them in better quality.  

 

 

Owners manual

           

Modifications:

 

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.

 

Sound:

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.

© Hans Hilberink - PE1MMK ® & Glenn Stewart - Last update: 12-04-2010.