Improving level control for 2nd VCO

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altitude
 
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Improving level control for 2nd VCO

Post by altitude »

So currently I simply have a pot that attenuates the signal to ground which is fed from the 2nd VCO and then into the junction of Q12 and C17 however if I turn the pot all the way down, both VCO's go silent. Can anyone recommend a more elegant way to control the level of a second VCO without loading down the main VCO?

Also on a related note, the way the x0xs0p kit turns the mod off and on is by using a 3 position switch with the center position being off. This off position however is not completely silent and I can hear the saw (mix maybe?) bleeding through. This is not board or switch related since I observe this on two different kits and regardless of the switch used..

Luap
 
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Re: Improving level control for 2nd VCO

Post by Luap »

Hey Alt.. I've never noticed any bleed/crosstalk issue with my 2nd VCO kit. Do you still hear it if you disable the original VCO? (I do that by simply holding the wave switch in a central position). I don't seem to get it at all, which makes me wonder if perhaps the location of the board, or maybe your level control has something to do with it?

I often wondered why the kit doesn't have a level control as standard, perhaps little complications like this made it unpractical?

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altitude
 
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Re: Improving level control for 2nd VCO

Post by altitude »

Luap wrote:... Do you still hear it if you disable the original VCO? (I do that by simply holding the wave switch in a central position)
Yes, it is really faint (if i didnt mention that)
I don't seem to get it at all, which makes me wonder if perhaps the location of the board, or maybe your level control has something to do with it?
it still does it with the level out of the equation
I often wondered why the kit doesn't have a level control as standard, perhaps little complications like this made it unpractical?
Not sure. both of the kits I have do it. One i sourced myself the other came from x0xsh0p. I have a solution for the level so i'll report back later tonight..

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isak
 
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Re: Improving level control for 2nd VCO

Post by isak »

Hi Alt.
This off position however is not completely silent and I can hear the saw (mix maybe?) bleeding through.
its strange..i bought 2 X 2VCO units from Sub and they are OK, no bleeds what so ever.

looking foreword to see what is your results about the bleeding test you doing.

cheers,
Isak E.

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altitude
 
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Re: Improving level control for 2nd VCO

Post by altitude »

I'm probably splitting hairs about this since I do all my audio testing on cans and usually at full volume. When I disconnect the main VCO, the bleed is actually lower in volume than the envelope firing; with the main VCO on, I cannot hear it at all.

The correct wiring for a level control pot is as follows, I use a linear 1 meg:

0- GND

0- VCO OUT (from VCO #2 PCB)

0- VCF IN (Q12/C17)

Apparently this is how they gang pots on guitars (AH to the rescue) so when you turn one all the way down, it does not short out the other.

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