REDUCED $600
The Sansui AU-9500 is an integrated amplifier from the mid 70s. I think, after replacing all the electrolytic capacitors and a few other components, it can compete with much of the modern audio amplifiers and if you like the black anodized faceplate and solid aluminum machined knobs there is nothing like it.
This is what I did:
1/ Replaced all the electrolytic capacitors with modern equivalents. The only exception being
the electrolytic caps in the signal path. These have been replaced with film types.
2/ Replaced power supply filter capacitors.
3/ Replaced 5B4 rectifiers with modern 6A bridge rectifiers.
4/ Replaced signal path ceramic capacitors with C0G types.
5/ Replaced the 2SA726 transistors with KSA992 and 2SC1313 with KSC1845.
6/ Replaced output speaker relay with new Omron relay
7/ Replaced variable potentiometers for bias and DC-offset adjustment.
8/ Replaced speaker A spring terminals with 3 way binding posts so it is possible to use bare
wire, small spade connectors or banana plugs.
The amp worked well and sounded good. Then Valery posted a Driver board and OPS of a Sansui BA-3000 he had modified to achieve lower distortion and promote soft clipping. Article here Revisiting some "old" ideas from 1970's - IPS, OPS
I put the driver board onto the 9500 Sansui “plug in” board and installed output transistors as in his design except 2 pairs instead of 3. Output power increased by 20W to 108W per channel. A few more changes were made but basically I was able to duplicate Valery’s circuit in the 9500. No major surgery in case I had to put it back, but no need, it sounds great. More modern but still with that Sansui character, what ever that is. Maybe it comes form the looks.🙂
$675.00 REDUCED $600
It will take a 22” x 24” x 10” box and will weigh about 58 lbs.
The Sansui AU-9500 is an integrated amplifier from the mid 70s. I think, after replacing all the electrolytic capacitors and a few other components, it can compete with much of the modern audio amplifiers and if you like the black anodized faceplate and solid aluminum machined knobs there is nothing like it.
This is what I did:
1/ Replaced all the electrolytic capacitors with modern equivalents. The only exception being
the electrolytic caps in the signal path. These have been replaced with film types.
2/ Replaced power supply filter capacitors.
3/ Replaced 5B4 rectifiers with modern 6A bridge rectifiers.
4/ Replaced signal path ceramic capacitors with C0G types.
5/ Replaced the 2SA726 transistors with KSA992 and 2SC1313 with KSC1845.
6/ Replaced output speaker relay with new Omron relay
7/ Replaced variable potentiometers for bias and DC-offset adjustment.
8/ Replaced speaker A spring terminals with 3 way binding posts so it is possible to use bare
wire, small spade connectors or banana plugs.
The amp worked well and sounded good. Then Valery posted a Driver board and OPS of a Sansui BA-3000 he had modified to achieve lower distortion and promote soft clipping. Article here Revisiting some "old" ideas from 1970's - IPS, OPS
I put the driver board onto the 9500 Sansui “plug in” board and installed output transistors as in his design except 2 pairs instead of 3. Output power increased by 20W to 108W per channel. A few more changes were made but basically I was able to duplicate Valery’s circuit in the 9500. No major surgery in case I had to put it back, but no need, it sounds great. More modern but still with that Sansui character, what ever that is. Maybe it comes form the looks.🙂
$675.00 REDUCED $600
It will take a 22” x 24” x 10” box and will weigh about 58 lbs.
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