Traynor YGM-3 (early) - Selmer cab

[Reeltarded]

Nothing like an old tech who's being doing this for 30 plus years!
Those were his diagnostic notes...and he's Scottish so imagine "Rubbish" and "Pish" said in that brogue...

In my mind he's clad in a dark tartan and and looking mostly through one eye.

[Barks]

Nothing like an old tech who's being doing this for 30 plus years!
Those were his diagnostic notes...and he's Scottish so imagine "Rubbish" and "Pish" said in that brogue...

In my mind he's clad in a dark tartan and and looking mostly through one eye.

And not wearing pants

[Reeltarded]

Umm.. yes, wee laads dun't need n'er legg't sleefs jamb'n up aur willahs.

[Barks]

Hi All

Just back with a general query about pots.

Are there different tapers for audio pots?

A while back I bust the volume pot on the Traynor which is a 1Meg Log (audio taper) pot.
It was very predictable up to about 6 with volume increase then it would get fatter sonically as the amp progressively got more overdriven - though no louder.
The point was it was very easy to define a clean or pushed setting.
I replaced with an Alpha 1Meg log pot and the taper is completely different. Volume is at max by about 3 on the dial and the rest is more progressive overdrive. Dodgy pot I thought so I got another and it has exactly the same taper.
The original pot is on the left of the picture:

88217575_10157770620701147_7196869577404317696_o.jpg

Any help appreciated.

[pompeiisneaks]

Hi All

Just back with a general query about pots.

Are there different tapers for audio pots?

A while back I bust the volume pot on the Traynor which is a 1Meg Log (audio taper) pot.
It was very predictable up to about 6 with volume increase then it would get fatter sonically as the amp progressively got more overdriven - though no louder.
The point was it was very easy to define a clean or pushed setting.
I replaced with an Alpha 1Meg log pot and the taper is completely different. Volume is at max by about 3 on the dial and the rest is more progressive overdrive. Dodgy pot I thought so I got another and it has exactly the same taper.
The original pot is on the left of the picture:

88217575_10157770620701147_7196869577404317696_o.jpg

Any help appreciated.

I've definitely seen and heard that different manufacturers implement it differently yes. There's no 'true' log pot anyway from what I gather, it's more of a dual sloped linear. I.e. slope is slow at first, then hits a kink point and increases, to simulate log.

Also I think I've heard some of the manufacturers do that 'shift' at different points, 10% 30% etc, and you can even request they do that for you in some way.

I'm not super familiar with how you do that, but your point is completely valid. If you want exactly identical behavior it's best to try to find NOS parts that are identical. Even the same companies tend to change processes over the years and it may be quite different for theoretical identical parts.

~Phil

[Barks]

Thank Phil

[pdf64]

Alpha USA standard audio taper is 15%, whereas CTS is 10%, so you may be better with the latter. Bourns are 10% too and are reputed to have a smoother taper implementation, eg better adjustment resolution for the user.
If you need to skew the taper a lot though, may be better to track down a 5% type.
But are you sure the old pot can’t be rejuvenated with some deoxit? It’s expensive but few pots are so bad that a good cleaner can’t fix them.

[martin manning]

I've measured a lot of the audio Alpha pots at 10%.