'C' potentiometer ??

[Adamo]

Is there such a thing as a '1kC' pot ? It's listed on a mbp schematic that I'm building. I've seen A's and B's but never C's.

[Groovenut]

Yes, the C is a reverse audio taper pot. Like the audio taper but in reverse. You should be able to find them in most outlets.

[knutolai]

You will also see it labeled as reverse logarithmic some places.

[Adamo]

Thanks very much!

[electrosonic]

I get my 1kC pots at small bear.

Andrew.

[davent]

You could simply wire a regular audio taper pot backwards if you can't find a 'c' taper. Now works backwards but it puts the flatter slope of the taper where you need it for finer control of change.

[KMG]

You can simply make dual "C" pot from dual "A" pot by swapping carbon track plates. Because dual "A" pot contain "A" and "C" carbon track plates.
http://www.gyraf.dk/gy_pd/calreq/magnus_j/rebuilding_pot.htm

[R.G.]

Read "The Secret Life of Pots" at geofex.com.

You can simply make dual "C" pot from dual "A" pot by swapping carbon track plates. Because dual "A" pot contain "A" and "C" carbon track plates.

I'm confused. Do you mean that all dual A taper pots have one A and one C taper resistive wafer (which is what the USA uses for what you call "carbon track plates"; BTW, I find carbon track plates a better description!).

I can see how some pot might have a top-side A taper and a bottom-side C taper that could be swapped around, but I've never seen that kind of face-to-face construction in a dual-A taper pot. All the ones I have seen have two identical A sections wiped from the same relative side. What brand did you find this in?

[KMG]

I've never seen that kind of face-to-face construction in a dual-A taper pot... What brand did you find this in?

For example
http://alphapotentiometers.net/html/16mm_rot_pot.html

[aion]

You can simply make dual "C" pot from dual "A" pot by swapping carbon track plates. Because dual "A" pot contain "A" and "C" carbon track plates.

I'm confused. Do you mean that all dual A taper pots have one A and one C taper resistive wafer (which is what the USA uses for what you call "carbon track plates"; BTW, I find carbon track plates a better description!).

I can see how some pot might have a top-side A taper and a bottom-side C taper that could be swapped around, but I've never seen that kind of face-to-face construction in a dual-A taper pot. All the ones I have seen have two identical A sections wiped from the same relative side. What brand did you find this in?

Alpha pots do this (see this documentation, pg 3)—it's a handy trick if you need to make a dual pot with different tapers, like the Boss SP-1 with the dual 10kA/10kC. But the "gotcha" is that the top wafer is inverted. So if you have aims to turn a dual 10kA into a 10kA/C for the SP-1, you don't do it by taking a wafer out of a C-taper single pot—you have to use an A-taper single pot as a donor. When the wafer is swapped into a dual pot, the "A" taper becomes a "C" taper. (The top wafer of a dual 10kA pot is actually a "C" taper from a manufacturing standpoint.)

[R.G.]

Ah. OK. I have seen the Alphas, just never took one apart. Makes sense now.

The duals I have taken apart are made from identical A taper wafers.

Good to know. Thanks!

[tubegeek]

This is very interesting - it means those dual pots could be used as a source for C taper wafers whenever those are hard to come by - thanks!

[aion]

This is very interesting - it means those dual pots could be used as a source for C taper wafers whenever those are hard to come by - thanks!

Yep, but the catch is, you can't disassemble an Alpha single pot without destroying it since the shaft is stamped into place during manufacturing. The duals can be fully disassembled, but the singles can't. So you can get the "C" wafer from a dual "A", but... you can't put it on anything

[tubegeek]

Oh.