Greetings,
I've been listening to a handful of Sansui amps from the 1970s in as is condition, for the most part i've been lucky they were fully functional and at most just needed some contact cleaner.
I'd like to get a little more hands on and get them to operate as they did when they were new. I'll begin hopefully a long journey of restorations with my AU6900 that powers on and operates great until you turn tone controls on.
Symptoms are static noise, and noticeable irregular movement of the LF drivers of the test speakers without playing any source material. Turn on tone defeat and it's back to performing normally.
So i've got together a tidy working space, and have started with dissembling the amp to access the tone board and the filter board.
These are boards F2606 (tone) and F2607 (filter). I naturally thought the problematic part would be on one of these two boards based on what i've found so far. But in any case i'd like to move through the whole amp one board at a time.
Tone board F2606:
Filter board F2607:
A list of parts i've listed from F2606 from what i recognize.
Capacitors
C01 - 0.47uF 50v
C02 - 0.47uF 50v
C11 - 2.2uF 50v
C10 - 22uF 25v
C09 - 22uF 25v
C12 - 2.2uF 50v
C15 - 10uF 25v
C13 - 100uF 6.3v
C16 - 10uF 25v
C14 - 100uF 6.3v
Transistors
TR02 - C1313 S65G
TR04 - C1313 S65G
TR08 - C1313 S65G
TR06 - A726 S56G
TR03 - C1313 S65G
TR01 - C1313 S65G
TR07 - C1313 S65G
TR05 - A726 S56G
TR10 - C1313 S65G
TR09 - C1313 S65G
Orange dish parts - not sure what these are, rated 0.022uF labeled 'KCK', there are 3 of these, and numerous smaller unmarked ones?
Green parts - again not sure what they are or if they're replaced or left alone?
So this is what i have so far, i still need to get a list of parts off board F2607, i'm hoping to have any opinions on the fault as well as recommendations on what i should be replacing and with what.
Many thanks!