Vintage Synth Repair

Im working an a Korg Delta with ADSR problems.

It seems that only the Sustain is working , both for the filter and VCA.
Any ideas before I start poking around ?

Thanks
Arnar

Hi Arnar,

Check IC4 (4007 cmos) or the +15volts to it via R66.

This IC seems ADR related on the schematic. Sustain seems seperate from the rest via the D+ power feed.

I'm no expert but I'd check IC4 first. Do you have the schematics?

Cheers,
TOM



--- In vintagesynthrepair@yahoogroups.com, "plat@..." <plat@...> wrote:

>
> Im working an a Korg Delta with ADSR problems.
> 
> It seems that only the Sustain is working , both for the filter and VCA.
> Any ideas before I start poking around ?
> 
> Thanks
> Arnar
>