Archive of the former Yahoo!Groups mailing list: Yamaha CS80
Subject: fun CS-80 repair - noisy voice card
From: "David" <david@...>
Date: 2013-02-17
Just got done fixing a CS-80 with a noisy voice card. The owner noticed a lot of hiss on Channel I, even when not playing any notes. Had to disconnect each card's output wire to pin it down to voice 3. Then started tracing and swapping. Turned out to be the generic NPN output transistor on the board. Conveniently, there are 5 other of the same type on the board, including 4 used in the octave switching. Swapped with one of those - where the noise doesn't cause any audible effect and it's all good!
Back to the freeways and another CS-80 (and a billion other projects) waiting at home! Can't complain too much since it's sunny and in the high 70s with a nice breeze :)