Yamaha CS80

On 5/21/2013 3:34 AM, pyjamagroove wrote:
> Hello,
> This is my first post here so - Hello everybody! My name is Tobias and last weekend I fulfilled my long time dream of getting (and actually playing for the first time) a Yamaha cs80. Unfortunately initial deep tests revealed two flaws of my machine - I have no aftertouch on middle G key and no sawtooth wave on voice1 card (channel 1). There are noise and square so I don't think it's a VCO or VCF or VCA chip. On the other cards at all channels everything seems to work fine. Anybody have an idea what it might be? Thanks in advance!
>

   Educated guess here is the analog switch to select the ramp waveform 
has failed.  It is called "FET6" on the M board.  The vintage part 
number is 2SK30, but just about any N-channel JFET will work here.  
2N3819, BF245, J112, etc.  Just observe the pin order.

Crow
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