MOTM

In a message dated 5/14/99 7:33:19 PM, tentochi@... writes:

>Not quite sure I understand the ground wire test.

I believe there exists equipment where audio ground isn't connected to the 
PSU ground so you would need to connect a wire across to both electrical 
grounds of the different synths. I use banana jacks and can attest to the 
need to make sure that you have a common ground between different systems, 
and to the fact that (when not done) the systems will behave very weirdly! 
But this is probably not the problem.

>Are there some simple tests I can do to more or less isolate the VCA? 
>The

If you have a second audio source (preferably MOTM to help isolate the 
problem) you can use your VCO in the subaudio range to control your VCA. 
Try this simple patch:
1) Noise (MOTM 100 -- or use a signal from a second VCO MOTM 300 if you have 
one) out to VCA IN.
2) VCO (MOTM 300) SINE OUT to VCA CV input.
Adjust VCO to a low frequency setting below the audio range.
3) Monitor the VCA output.

You should hear the amplitude of your signal source change at the rate 
determined by the sine wave of the VCO.

>Ring Mod portion seems to be OK.

The pot I recently mentioned frying, was the CV MOD pot on my 110 -- the VCA 
would work properly at low CV input levels, but cut out just a little above 
it. As I said, it took a while to figure out where the problem lay.

>BTW, I have not touched to pots yet on my VCO.  I would believe this would
>
>make a difference, right?

I don't understand this bit.

Happy hunting!
John B.