Author Topic: Dual gang pots  (Read 178 times)

Aentons

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Dual gang pots
« on: October 10, 2018, 09:21:53 AM »
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?

EBK

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Re: Dual gang pots
« Reply #1 on: October 10, 2018, 09:35:34 AM »
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.
« Last Edit: October 10, 2018, 09:40:13 AM by EBK »
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Aentons

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Re: Dual gang pots
« Reply #2 on: October 10, 2018, 09:44:48 AM »
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.
« Last Edit: October 10, 2018, 11:05:04 AM by Aentons »

m-Kresol

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Re: Dual gang pots
« Reply #3 on: October 10, 2018, 11:58:55 AM »
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.
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dan.schumaker

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Re: Dual gang pots
« Reply #4 on: October 10, 2018, 12:23:40 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

madbean

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Re: Dual gang pots
« Reply #5 on: October 10, 2018, 12:27:17 PM »
They are custom ordered. You'd be looking at a minimum of 1000 to get any, I'm afraid.
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Aentons

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Re: Dual gang pots
« Reply #6 on: October 10, 2018, 12:32:57 PM »
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

jduma

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Re: Dual gang pots
« Reply #7 on: October 10, 2018, 08:00:27 PM »
This is what I did for some Vfe project just combined a C10 with a C100 dual.

alanp

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Re: Dual gang pots
« Reply #8 on: October 10, 2018, 10:11:47 PM »
Use a normal dual-gang, with resistors across the lugs of one of them to get the taper/resistance you want. Easiest way.
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EBK

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Re: Dual gang pots
« Reply #9 on: October 11, 2018, 02:03:20 PM »
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."
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Aleph Null

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Re: Dual gang pots
« Reply #10 on: October 11, 2018, 06:51:27 PM »
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?