What taper do i need?

[daz]

Whatever the typical taper that is used on the 500k pots in LPs and other gibsons these days, i find that i want the volume to drop gain faster than they do. I'd like the volume to clean up the same when on 5 as they do now on 3. What % do i want? Don't bother with equasions, i can barely add 1+1 let alone typical electronics math/theory.

[pdf64]

It seems that you need a taper with a lower % than what you've currently got in there.
10% is about the lowest, commonly available standard taper. CTS and Bourns are typically 10%, Alpha 15%.

[J M Fahey]

That.

Standard Audio/Log taper is 10%, which allows for +20dB (10X)b raise from 5 to 10.

Most useful ytaper, a given in all classic HiFiddesigns from the 40s on.

But some Guitar amp marketers wanted to impress naive buyers: "hey, it´s only on 2 and it´s already ery loud,. on 10 it will bring the roof down"

So soime started cheting (Fender cough cough) so they went to 15%

Now they are already at 30% which is ridculous and some (including HRDs and similar) straight use linear volume controls, which are 50% ... unusable and lots of people complain.

https://www.banzaimusic.com/fender-p...0a-1m-log.html

"Volume control for Twin 65 reissue" .... a scam if you ask me.

CTS offered various tapers on demand:







This is the faked audio pot adding a load resistor from wiper to ground

[pdf64]

It's worth noting that adding a load resistor to bring the effective taper % down isn't a good option for a guitar volume pot, as when set to full volume, the load resistor will hobble the pickup's treble resonance (ie a big effect on tone).

[Helmholtz]

Also a treble bleed circuit counteracts a rapid volume decrease.

[daz]

Also a treble bleed circuit counteracts a rapid volume decrease.

I know, ad i do use a TB cap. But its absolutely mandatory for me. And no, 50s wiring won't do plus i don't even have tone controls hooked up. So i supposed theres no way to accomplish what i want. thanks anyways all....

[Helmholtz]

For some a volume pedal after a buffer or buffered pedal is a better solution.

[Tom Phillips]

...I supposed there's no way to accomplish what i want. thanks anyways all....

There is a way. You can replace the volume pot with a pot of the same resistance value but with a different taper as discussed above.

[daz]

There is a way. You can replace the volume pot with a pot of the same resistance value but with a different taper as discussed above.

Thats what i asked, but from responses so far it appears a CTS which is what the pot is are 10% so it appears there's nowhere to go from there.

[pdf64]

Thats what i asked, but from responses so far it appears a CTS which is what the pot is are 10% so it appears there's nowhere to go from there.

Standard CTS audio taper is 10%, but provided you meet their minimum batch quantity, CTS etc will make whatever taper is requested. And we don't know what Gibson requested.

My '78 Pro Deluxe had 250k linear, whereas my R8 has 300k 10% audio.

[Greg Robinson]

First I'd make sure to check what you actually have. Gibson have been known to use LINEAR taper pots for volume controls at certain points throughout their history, which could certainly result in your experience.
Before we can make proper recommendations, we need to be sure what you've actually got now.

[daz]

First I'd make sure to check what you actually have. Gibson have been known to use LINEAR taper pots for volume controls at certain points throughout their history, which could certainly result in your experience.
Before we can make proper recommendations, we need to be sure what you've actually got now.

Did that long ago. Measures almost exactly 500k and is definitely audio.

[Greg Robinson]

But what taper audio?

[Tom Phillips]

It's very worthwhile to measure the actual pot taper.

I made a jig to assist in measuring actual pot taper using a salvaged about 3" dial plate and a long pointer knob. The plate was pre-printed the full 360 degrees around. It made it easy to evaluate the taper of a batch of pots from several manufacturers sorting through both current and old stock parts. The motivation was to assist in finding tapers that I could select when a client wanted to change out a pot that that wasn't performing to their liking.

It was surprising to discover how different the various pots, which were all considered audio taper, performed. Having actual measurements made it easier to choose candidates without mounting each one in the customer's amp. The data also uncovered BS marketing and supplier mistakes.

Edit: I dug out my stash of pots for which I have actual measured taper data. There are 13 pots in the stash. All except one include "Aud" or "Audio" along with the value marking. The actual measured tapers range from 7% to 36% with clusters around 10%, 15%, and 30%. It would be interesting to know the original specified taper and tolerance but that data is not decipherable to me based on the other markings on the pot body. It is likely that most of them were custom large quantity production orders and the client could therefore specify any reasonable taper value.