Yamaha CS80

--- In yamahacs80@yahoogroups.com, rj krohn <r_j_d_2.phila@...> wrote:
> TP1 -.66V;0V at trigger -.66V; .87V at trigger

Well, that's the cutoff voltage to the filters, so there is the problem. 

--- In yamahacs80@yahoogroups.com, "kent_spong" <kent_spong@...> wrote:
> Just a guess here but try swapping out the VCF EG's VCA (151)

Yeah - I think that's the most likely. You can swap the suspect 151
(IC1) with IC3, which controls the sine-wave level. Luckily, assuming
it fixes it, the CS80 has about a billion of these chips, along with
the other CS and SK synths and many Electone organs from the era, so
it shouldn't be too hard to find a replacement.

Make sure you put it in the right way!

 David