Best potentiometer brand - Alpha, CTS or PEC?

[novosibir]

I've never had an Alpha that took solder well on the case. Are you sanding them?

This is a MUST, otherwise they don't take solder on their backs.

Larry

[BrianH]

In my experience, the Alphas definitely need some sanding.

[Structo]

PEC pots are good quality but if they ever get a little scratchy, you can't use DeOxit because the pot is sealed.
But then again, high quality pots rarely get scratchy in the first place.

[mwm523]

I'm using Alphas in all my amps and Marshall rebuilds since 1995 - and these were many, but not only one prob yet!
I've used CTS in most of my Fender rebuilds, but some people claimed after a while, that the pots are turning too strong and seem to stick in its position, if it wasn't used over a longer time.
And I've built only one DINO with PEC's as an exception by customer's advice, but couldn't get the same warmth out of this amps as opposed to DINO's supplied with Alpha's...
... and the reason is quite simple! The Alpha's do have a taper of CC, the PEC's of conductive plastic.

Moreover I didn't like the turning feel of the PEC's, what was nearly like there's a grinding paper inside between the wiper and the taper - far not as smooth as the Alpha's. And I don't like the positions of the solder lugs on the PEC's, don't like the too long bushing and the too long shaft.

Larry

Hi Larry, the PEC pots George has in the MetroAmp store are carbon, not conductive plastic.

http://metroamp.com/store/index.php?mai ... cts_id=341" onclick="window.open(this.href);return false;

[novosibir]

Hi Larry, the PEC pots George has in the MetroAmp store are carbon, not conductive plastic.

http://metroamp.com/store/index.php?mai ... cts_id=341" onclick="window.open(this.href);return false;

Ah-ha! Interesting, thanks!

But what stays is the too long bushing and the too long shaft - and as soon as you cut the shaft, they start to run grindy.

Larry

[jbzoso2002]

You dont need to solder the grounds there anyway's.

Germino dosent ground the back of the pots,
and on the printed circuit board amps, no ground
on the back of pots.

All my amp builds (ok only 4) ive never soldered the
back of the pots and the amps are just fine.

I did that cause I ruined some pots in a guitar by
over heating them back in the 90's.

Jimmy

[demonufo]

Hi Larry, the PEC pots George has in the MetroAmp store are carbon, not conductive plastic.

http://metroamp.com/store/index.php?mai ... cts_id=341" onclick="window.open(this.href);return false;

Ah-ha! Interesting, thanks!

But what stays is the too long bushing and the too long shaft - and as soon as you cut the shaft, they start to run grindy.

Larry

Too long a bushing isn't much of an issue. Simply get a lockwasher and another nut, and space it out from the back of the chassis, so as only the correct amount sticks through the front of the panel. As for the shaft, well I don't mind being able to see a little bit of gap behind it, at least I know it's not rubbing the panel.

[mwm523]

Hi Larry, the PEC pots George has in the MetroAmp store are carbon, not conductive plastic.

http://metroamp.com/store/index.php?mai ... cts_id=341" onclick="window.open(this.href);return false;

Ah-ha! Interesting, thanks!

But what stays is the too long bushing and the too long shaft - and as soon as you cut the shaft, they start to run grindy.

Larry

Too long a bushing isn't much of an issue. Simply get a lockwasher and another nut, and space it out from the back of the chassis, so as only the correct amount sticks through the front of the panel. As for the shaft, well I don't mind being able to see a little bit of gap behind it, at least I know it's not rubbing the panel.

Right, I don't cut the shafts either. I use an extra nut on the inside of the chassis, which gives me just enough thread on the outside to tighten it securely. The length of the shafts makes the knob stick out just a little bit, but it's really not bad at all. See below:

[demonufo]

Right, I don't cut the shafts either. I use an extra nut on the inside of the chassis, which gives me just enough thread on the outside to tighten it securely. The length of the shafts makes the knob stick out just a little bit, but it's really not bad at all. See below:

Mondo tidy build there too, Mike!

[LJay942]

Right, I don't cut the shafts either. I use an extra nut on the inside of the chassis, which gives me just enough thread on the outside to tighten it securely. The length of the shafts makes the knob stick out just a little bit, but it's really not bad at all. See below:

Everytime I see that build I weep.

Fantastic job.

[Doug H]

what's with those output caps? they look fatter than the 22s on the board but aren't a .1 either...

[novosibir]

what's with those output caps? they look fatter than the 22s on the board but aren't a .1 either...

You probably meant .022's ?

The ones in doubt are .047's

Larry

[V8]

Alpha are carbon composition and PEC are hot molded carbon

Found this, lists the various material used in pots
http://www2.eem.com/Potentiometers_Trim ... trols.aspx" onclick="window.open(this.href);return false;

[novosibir]

Alpha are carbon composition and PEC are hot molded carbon

What explains the difference soundwise, what i.e. I've noticed here:

And I've built only one DINO with PEC's as an exception by customer's advice, but couldn't get the same warmth out of this amps as opposed to DINO's supplied with Alpha's...
... and the reason is quite simple! The Alpha's do have a taper of CC, the PEC's of conductive plastic.

... but was wrong so far, that I thought, the PEC's are conductive plastic.
But now it seems to be proofed, that also hot molded carbon isn't the same soundwise as CC

Larry

[V8]

But now it seems to be proofed, that also hot molded carbon isn't the same soundwise as CC

Yeah the composition isn't the same & you guys can hear it. At some point I'll have swap out the PEC & drop in the Alf's in my JTM clone.