Is there anywhere you can get multi-value dual gang pots similar to the ones used in the VFE Standout, Dragon, and Pinball?
C10k/C100k Custom PCB Dual-Gang 16mm
Is it the different values that are custom about these, or is it tolerance, or taper, or something else?
I hate to say it, but I would be tempted to consider such a pot to indicate a very serious design error in the circuit that supposedly needs it. I really want to be convinced otherwise.
Interesting... I'm looking to do a similar application as the VFE stuff, a variable 2pole hpf and lpf. Is there another way to go about this that you would recommend?
Are you saying just a regular A100k dual gang should work fine for most applications?
BTW, I'm also open to 9mm pots if anyone has a source for those.
one of Aeon electronics' build docs has a tutorial on how to do that based on 2 single pots. Basically you remove one resistor element of a dual pot and replace it with another from a mono pot.
Shoot him a PM or go on a scavenger hunt, I don't know which doc it was.
Quote from: m-Kresol on October 10, 2018, 05:58:55 PM
one of Aeon electronics' build docs has a tutorial on how to do that based on 2 single pots. Basically you remove one resistor element of a dual pot and replace it with another from a mono pot.
Shoot him a PM or go on a scavenger hunt, I don't know which doc it was.
It was for the Aion Chroma
They are custom ordered. You'd be looking at a minimum of 1000 to get any, I'm afraid.
Hmmm... So what's the benefit of multi-value vs using a regual dual 100k? Is there something special about Peter's design that requires it? steeper slope, less resonance... etc
This is what I did for some Vfe project just combined a C10 with a C100 dual.
Use a normal dual-gang, with resistors across the lugs of one of them to get the taper/resistance you want. Easiest way.
Here is some info regarding making HP and LP filters with more readily available dual gang pots:
http://sound.whsites.net/project155.htm
One particularly relevant part reads: "a traditional Sallen-Key 12dB/octave filter needs a dual-gang pot with different resistances. These are not available. You could have them specially made but that will be a very expensive exercise indeed. The easy way to get around the problem is to give the filter opamp (U1B) some gain."
With single pots, it's possible to open them up and replace or modify the resistant plate the wiper goes over. Is there a E reason you couldn't order two dual gang pots in the values you need, the mix and match the plates?