What a difference a pot makes

[FiddlinJim]

A little tip about volume pots...

I built my 5E3 with Alpha pots (1M Audio) and had pretty extreme volume sensitivity around 2-3, which is pretty normal. My bright channel pot went a little wonky (dead spots), so I decided to try out the Allesandro 2-Watt pots and the results really surprised me. The audio taper seems much more usable for this circuit for me. $15 is a lot of money for a pot, but it sure made my deluxe more usable for me.

I've also done and reversed a volume/tone type mod (great mod, but less of a tweed deluxe), done and reversed a Paul C mod (took away some of the midrange roar... I might re-do this mod some day). I did change the preamp coupling caps from .1 to .02 and that seems to have brightened 'er up a bit.

[Enzo]

$15 is a lot.

All "audio" tapers are not the same. Look up the curves on your new pot versus the Alpha. Cost of a pot is not an indicator of its taper. It is not at all rare to find two different audio tapers in the same Fender amp. The pots you buy from Mouser will all be the same as each other, but you can also buy pots from Fender or Peavey or Marshall in other tapers. Tapers that might be more desirable in your circuit. You will have to find them in circuits to identify them, but they are there.

Also, you can hang resistors in parallel with all or part of your existing pot to alter its taper, or even start with a linear. Go over to RG's Geofex site and look up the secret life of pots under tech tips

[FiddlinJim]

Points certainly well taken Enzo. I'll look up "the secret life of pots" and try to learn something (I'm always up for that). It does so happen that the taper them there Canadians put in this pot fits my circuit nicely, so I'll keep it at that. Next time, perhaps I'll do a little more research and save a few bucks.

[Bruce / Mission Amps]

Points certainly well taken Enzo. I'll look up "the secret life of pots" and try to learn something (I'm always up for that). It does so happen that the taper them there Canadians put in this pot fits my circuit nicely, so I'll keep it at that. Next time, perhaps I'll do a little more research and save a few bucks.

YIKES!! $15 each?

I'd be very interested in you doing this...
With the pot disconnected from anything, turn the pot exactly half way up and measure the DC resistance from each outside leg to the center wiper leg... and tell us what the taper is.
EX:
1000K pot,
wiper to the normally grounded side, 100K and wiper to audio high side 900K.
I'd call that ratio a 10% audio taper.

However, I find "audio taper" pots from less then 10% to as much as 30%... yet they are all sold as audio or log taper pots.

[FiddlinJim]

Bruce, I would, but I just installed both of the pots I have this weekend. I might convince myself to open it back up and disconnect for the test... It won't be for a couple of days, though.

Yeah, $15 is a lot, I know. Sort of an impulse item. "Add to cart" was yelling at me to do so. At least I didn't spend $40 on the guitar pots they have...

Can you comment on the pots that you're preferring in the 5E3 these days? I think I saw a posting from you about CTS pots from Mojo. Are they the brass solid-shaft CTS ones?

[soundmasterg]

In my experience, its getting hard to find good quality audio taper pots these days. Everything seems to make the volume come on too quick, or go down too fast, and tone pots on a guitar don't do anything until you get to 3. I've tried CTS, Alpha, Webervst among others.

Greg

[Enzo]

It is all about the taper. If you don;t like the taper, the highest quality pot in the world won't perform any better. That is why I suggest looking into something like a 30% taper pot from a Fender model versus a 10% one or vice versa.

[fyl]

I decided to try out the Allesandro 2-Watt pots

They are standard PEC RV4 pots rebranded by Alessandro.

http://www.precisionelectronics.com/

PEC pots are available for $9 or so apiece (with substantial quantity discounts) from a number of distributors - check for instance Digi-Key.

[Bruce / Mission Amps]

Bruce, I would, but I just installed both of the pots I have this weekend. I might convince myself to open it back up and disconnect for the test... It won't be for a couple of days, though.

Yeah, $15 is a lot, I know. Sort of an impulse item. "Add to cart" was yelling at me to do so. At least I didn't spend $40 on the guitar pots they have...

Can you comment on the pots that you're preferring in the 5E3 these days? I think I saw a posting from you about CTS pots from Mojo. Are they the brass solid-shaft CTS ones?

Yes, the brass bushing, solid shaft pots... I think they are pretty good and not very much money...but I am not sure the taper is 100% correct.
With respect to all those Fender style, tweed volume tone control type amps, I struggle with it just like everyone else.
MOJO has also contracted Mouser to build some 1M audio, solid shaft with a brass bushing, made in Taiwan pots too. Those are not too bad and very low cost.