# Best Pot Makers?



## keeperofthegood (Apr 30, 2008)

Hey oh

I was wondering who as I have some pots that are 50 years old and solid still and others that are a year old and now crud? And, in audio is there a tone difference with wire wound vs carbon?

Link me some recommendations 

1meg, 500k, 250k, and 100k, dual pots as well as singles are what I am interested in. Wattage under 1 watt I think should do, but I have to look into a tone balance system that I encountered this week that uses what looks like 2 or 3 watt wire wound trimmers too.


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## Jim DaddyO (Mar 20, 2009)

I hear the stuff coming out of BC is good! lol.


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## keeperofthegood (Apr 30, 2008)

Jim DaddyO said:


> I hear the stuff coming out of BC is good! lol.












Good one


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## Sneaky (Feb 14, 2006)

CTS (Chicago Telephone) seem to be the standard for decent quality pots these days (and for the last 50-60 years).

Some interesting stuff here...

http://zeus.lunarpages.com/~jimshi2/potcodes/potcodes.ht


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## parkhead (Aug 14, 2009)

pec /clarostat

made in canada 2 watt pots 

at $12 to $15 a pot they must be grown in BC 

p


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## Wild Bill (May 3, 2006)

keeperofthegood said:


> Hey oh
> 
> I was wondering who as I have some pots that are 50 years old and solid still and others that are a year old and now crud? And, in audio is there a tone difference with wire wound vs carbon?
> 
> ...


We don't have the choices of manufacturers that we used to, Keeper! Sometimes you take what you can get!

Almost all pots these days are made offshore. Alpha is a common brand. If you look at many CTS pots you might have a hard time telling the difference and might suspect they are just Alphas rebranded.

PEC make excellent pots to the specs of the Golden Years. They are made in Scarborough, Ontario. To my knowledge, they are the only ones left making the mil spec RV4 style. The problem is cost and also finding audio tapers!

Most pots come in one of two tapers, linear and audio. There are some fancy exceptions but that's not important right now. Linear means that if you crank the pot 25% of the way up you get 25% of the resistance and it will track the same all the way up to 100%.

This is fine for a motor control and in some circuits but no good for a volume control. The human ear doesn't track like that. As you advance the volume you need a greater and greater change to sound like a smooth increase. If you measure an audio taper pot you might find that at 50% rotation you are still only at maybe 25-30% of the resistance. Most of the change will come in the last half of the rotation.

You can find linear taper pots anywhere but audio pots are sold in far less volume so often at electronics stores that still sell in small volumes you just can't find them. In fact, most often the salesperson doesn't even know the difference! So you wire in the pot and wonder why the volume maxes out at only 25%, with no further increase as you crank it up.

Manufacturers buy their pots in volume so they get whatever they want. A small store cannot afford to ask PEC to ship them 5-10 pcs of audio taper 1meg, 10 pcs of 250 k and so on for their stock. They would have to order a few hundred of just one value! It might take them 100 years to sell them all! Especially when those high quality PEC's cost them so much they have to sell them for $15 or so.

So far I haven't seen a source for audio PEC types but if there is one they won't be cheap! That's why everyone orders Alpha from places like http://tubesandmore.com who will sell in small quantities to guys like us. For the money they are not bad quality and I've only had a couple of problem units over the years.

You asked about tone difference. Resistance is not a tone factor, other than the obvious point about different values are used in different tone stacks. It attenuates ALL signals equally, regardless of frequency! That is the very textbook definition of resistance.

However, wirewound is a very poor choice for audio applications. The wiper bumps across the wire element, causing unpleasant noises. Carbon or conductive plastic resistance elements are smooth and much quieter. Wirewound is normally used when the control will handle higher amounts of current, like when controlling a motor or some other power load. Audio is just a voltage signal with next to zip all current involved. Different application entirely.

Hope this is useful!

:food-smiley-004:


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## GTmaker (Apr 24, 2006)

PEC (precision electronics company )
http://www.precisionelectronics.com/Product Specs.htm

my humble opinion, BEST pots available. My local electronics shop carries this brand. With a +- 10% range, these pots are expensive and amazing.

These pots do come with a strange problem if you have to ground solder to the pot body. THE SOLDER WONT STICK TO THE CASING...you have no idea what I had to do to instal 2 PEC pots in my tele.

IF you can get around this strange oddity, try them out, you wont be disapointed.


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## keeperofthegood (Apr 30, 2008)

GTmaker said:


> PEC (precision electronics company )
> http://www.precisionelectronics.com/Product Specs.htm
> 
> my humble opinion, BEST pots available. My local electronics shop carries this brand. With a +- 10% range, these pots are expensive and amazing.
> ...


@GTmaker
Only two things come to mind. 1) Aluminum, or 2) a coating. A magnet here would tell you the answer to 1 

@Wild Bill  Thank you! I had a 1925 Spartan used a wire wound pot for volume. It had a complicated spring and roller bar deal and the bar rolled across the wires, chatter does make sense now that you mention it. I never got her to light up, had my son instead and POOF there went my time. I have an Armco (sp?) stereo amp that has two wire wound trimmers labeled as "hum-adj" that look to be part of the output transformers (but I am not 100% on that, winter project to trace out the schematic and get a 6BM8 to see if it will fire up).

I have some "Alpha" labeled pots I got for 0.97 cents from The Source of their clearances the last little bit. I was not aware this was not a "source" company, I will have to have a deeper look into them then


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## nonreverb (Sep 19, 2006)

keeperofthegood said:


> @GTmaker
> Only two things come to mind. 1) Aluminum, or 2) a coating. A magnet here would tell you the answer to 1
> 
> @Wild Bill  Thank you! I had a 1925 Spartan used a wire wound pot for volume. It had a complicated spring and roller bar deal and the bar rolled across the wires, chatter does make sense now that you mention it. I never got her to light up, had my son instead and POOF there went my time. I have an Armco (sp?) stereo amp that has two wire wound trimmers labeled as "hum-adj" that look to be part of the output transformers (but I am not 100% on that, winter project to trace out the schematic and get a 6BM8 to see if it will fire up).
> ...


Hey,

Those hum adjust trimmers might be across the filament windings to ground. No surprising that they're wire wound pots.:smile:


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## GTmaker (Apr 24, 2006)

Wild Bill said:


> Manufacturers buy their pots in volume so they get whatever they want. A small store cannot afford to ask PEC to ship them 5-10 pcs of audio taper 1meg, 10 pcs of 250 k and so on for their stock. They would have to order a few hundred of just one value! It might take them 100 years to sell them all! Especially when those high quality PEC's cost them so much they have to sell them for $15 or so.
> 
> So far I haven't seen a source for audio PEC types but if there is one they won't be cheap! That's why everyone orders Alpha from places like http://tubesandmore.com who will sell in small quantities to guys like us. For the money they are not bad quality and I've only had a couple of problem units over the years.
> 
> ...


ALL TRUE...

I contacted PEC as a possible reseller...They asked for a minimum 200 piece order for just one model.
Just to be clear, my local electronics store only has linear PEC pots. I have asked many times for them to get audio taper but no luck so far.

By the way, I did get a nice sample box from PEC...


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## jimihendrix (Jun 27, 2009)

bourns are touted as being the best...they are currently installed on the new gibson les paul standards...

http://www.bourns.com/ProductLine.aspx?name=precision_pots_multiturn


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## WCGill (Mar 27, 2009)

PEC's rule. CE Distribution sells them (wholesale only) branded Alessandro because smilin' George got a run with his name on them. Antique Electronic Supply, CE's retail arm carries the line for the common man also. These are the audio taper ones you need.


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## Shiny_Beast (Apr 16, 2009)

http://metroamp.com/store/index.php?main_page=index&cPath=22_33_64


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## Wild Bill (May 3, 2006)

GTmaker said:


> These pots do come with a strange problem if you have to ground solder to the pot body. THE SOLDER WONT STICK TO THE CASING...you have no idea what I had to do to instal 2 PEC pots in my tele.
> 
> IF you can get around this strange oddity, try them out, you wont be disapointed.


The only place I ever see someone soldering to the pot casing is in guitars. I attribute this to the fact that most guitar guys are much better with wood than they are with electicity!

DON'T DO IT! There's some kind of idea that the way to reduce or eliminate hum is to try to completely encase the wiring in a cage of metal. Also, you can ground anywhere you like and it makes no difference, like using a care frame as the negative return.

Both these ideas are also wrong. In fact, grounding all over the place can ADD hum! That's how ground loops are formed.

Finally, the case of most pots is usually already grounded to the bushing and thus to the chassis.

The best way to wire a guitar is to bring all grounds to just one point and from that point to the ground at the jack for the guitar cord. No ground loops that way. Ground loops are great high gain antennae for hum!

If things are so bad that you need shielding, there are other options. Here's a great link!

http://www.guitarnuts.com/wiring/index.php

If you truly need full body cavity shielding, this site will tell you how to do it the right way!

It's a bit confusing navigating this site. Look for links on the lower half of the left hand menu. The top half seems to bring you over to advertising stuff.

:food-smiley-004:


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## Volke (Sep 4, 2009)

Wild Bill said:


> The best way to wire a guitar is to bring all grounds to just one point and from that point to the ground at the jack for the guitar cord. No ground loops that way. Ground loops are great high gain antennae for hum!


In the examples I've seen, and when I wire a guitar, it is the case of the pot that is the easiest place to bring all other grounds, it is a large surface to pop on the connections, and from that point I go to the ground at the Jack. So essentially, it's the same theory with differing execution, no?


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## Wild Bill (May 3, 2006)

Volke said:


> In the examples I've seen, and when I wire a guitar, it is the case of the pot that is the easiest place to bring all other grounds, it is a large surface to pop on the connections, and from that point I go to the ground at the Jack. So essentially, it's the same theory with differing execution, no?


Well, that's not the real worry. When you solder to the case you often have to heat the hell out of it! This can damage the resistance element inside, screwing up the pot. Also, unless your pick guard has no metallic shielding tape there will be another ground connection through the pot bushing to the other pots.

:food-smiley-004:


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## Volke (Sep 4, 2009)

Wild Bill said:


> Well, that's not the real worry. When you solder to the case you often have to heat the hell out of it! This can damage the resistance element inside, screwing up the pot. Also, unless your pick guard has no metallic shielding tape there will be another ground connection through the pot bushing to the other pots.
> 
> :food-smiley-004:


Oh yeah, good point. Thanks for the clarification mister =)


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## greco (Jul 15, 2007)

Wild Bill said:


> ....... heat the hell out of it! This can damage the resistance element inside......
> :food-smiley-004:


Voila...hot pot = crisper resistor

Cheers

Dave


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## jstring (Nov 11, 2009)

*Grounding*

Hey Wild Bill
Thanks for all that great info. I have 4 Alessandro R-V250KA-SS-AHE on the way from Antique Electronic Supply in Arizona which is kind of ironic seeing that I am about 20 minutes away from Precision Electronics here in Ontario. Anyways I want to make sure that the ground terminal on most pots if you are looking down the shaft is the terminal on the right or if you are looking at the pot from its bottom it is the terminal on the left? So I just use this terminal instead of soldering to the body of the pot. 
jstring


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## WCGill (Mar 27, 2009)

You got it!


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## nonreverb (Sep 19, 2006)

Wild Bill said:


> Well, that's not the real worry. When you solder to the case you often have to heat the hell out of it! This can damage the resistance element inside, screwing up the pot. Also, unless your pick guard has no metallic shielding tape there will be another ground connection through the pot bushing to the other pots.
> 
> :food-smiley-004:


Hey Bill, I'm not trying to cross the grain of your comments but I personally don't believe that soldering to a pot case, particularly CTS type case, is all that bad since the resistive element is on the other side of the case and contacts only the edge of the rim of it. Ground rails have been soldered to the back of pots for years in some amps as well as most guitars without incident. I would contend that the potential for damage could be as great soldering wires onto the terminals of a pot if excessive heat was used or for a long duration.IMO:smile:


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## Wild Bill (May 3, 2006)

nonreverb said:


> Hey Bill, I'm not trying to cross the grain of your comments but I personally don't believe that soldering to a pot case, particularly CTS type case, is all that bad since the resistive element is on the other side of the case and contacts only the edge of the rim of it. Ground rails have been soldered to the back of pots for years in some amps as well as most guitars without incident. I would contend that the potential for damage could be as great soldering wires onto the terminals of a pot if excessive heat was used or for a long duration.IMO:smile:


Well, it depends on who's doing the soldering!:smile: I'll agree that you and me can usually do it with no problem. It still leaves the question of ground loops but the resistance element should be ok.

My worry is amateurs! I've seen horrible examples of soldering, often from places that should know better, like music stores. I swear that it often looks like they didn't own a soldering iron so they heated up a nail on the stove!

I'll wager you've seen scary soldering too! What do you think most amateurs do when they get one of those pots with the coating or whatever that keeps the solder from sticking? They nuke the poor thing trying to get the solder to stick, that's what! Especially if they don't have a large iron or gun but rather a small pcb iron. In order to get the case hot enough to make the connection they have to hold that little iron on the case for a long time to make things REALLY hot, rather than a quick application of a bigass iron tip! Couldn't that bother the resistance element?

Still, it's ground loops that are most worrisome. Yes, factories have used pot cases as grounds for years. However, some models of guitar have also had more hum than they should for years.

You don't always have to use star grounding techniques. Many vintage amps and radios from the golden years used chassis grounds. However, those old guys knew what they were doing better than most of us today. They also didn't mind scrapping a few chassis on their design bench until they got it right. The advantage to methods like star grounding is that it ALWAYS keeps you out of trouble! It's the safest thing to teach a newbie so that he doesn't end up wasting his time and his money if he gets into hum problems.

I often get guys bringing me amps where they got someone else to do some mods and the amp hums and squeals. Almost always the problem turns out to be ground loops from the mod wiring changes. A little re-arranging of the ground points and the amp usually settles right down.

Wiring a "cat's cradle" among the pots of a guitar by grounding all the pot cases can get you into trouble, but I won't disagree with you that it CAN be done right! That being said, I find that it's just as easy if not easier to star ground without using the cases. I've never had an instance where grounding the pot case helped with the hum but I have had cases where it had made things worse.

:food-smiley-004:


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## nonreverb (Sep 19, 2006)

Wild Bill said:


> Well, it depends on who's doing the soldering!:smile: I'll agree that you and me can usually do it with no problem. It still leaves the question of ground loops but the resistance element should be ok.
> 
> My worry is amateurs! I've seen horrible examples of soldering, often from places that should know better, like music stores. I swear that it often looks like they didn't own a soldering iron so they heated up a nail on the stove!
> 
> ...


+1 on the star ground:smile: As for amateurs and soldering guns, well...There's nothing like working on an amp loaded with pipe solder put there with a 140 watt Weller gun...


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## greco (Jul 15, 2007)

Is this a good time to advertise my 130 watt soldering iron? (seriously...it is that powerful. A gift from my father).

Great thread. Thanks

Dave


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## WCGill (Mar 27, 2009)

I'm not a big fan of soldering of pot bodies either, never done it. First, it takes too much heat and secondly doesn't lend itself to proper grounding technique. I know Leo got away with it and even Ken Fischer did it on his Trainwrecks, which can be notorious for unwanted noise when someone builds one. Kudos all around!


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## nonreverb (Sep 19, 2006)

WCGill said:


> I'm not a big fan of soldering of pot bodies either, never done it. First, it takes too much heat and secondly doesn't lend itself to proper grounding technique. I know Leo got away with it and even Ken Fischer did it on his Trainwrecks, which can be notorious for unwanted noise when someone builds one. Kudos all around!


One of the problems with excessive heat on pots is simply that people dont take the time to prep the cover before they solder. All it takes is a small spot where the coating is removed using a file or sand paper and it makes the job much easier and uses less heat. A Dremel and a small grinder bit to gently score the surface works quite well.


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## jstring (Nov 11, 2009)

*pots and capacitors*

Since we're on the pot subject. I'd like to ask if I can reuse the capacitors that run between my volume pot and tone pot when I put in the new pots?
I play guitar but I have an old Odyssey Bass with Bartolini's that I use for recording and I am putting the new Alessandro pots in it. I think the capacitors are used as treble cut and they are black flat round things with 47ns written on them and rather than try to find a replacement for them since I know nothing about capacitors, can I unsolder them and resolder them to the new pots? Thanks
jstring


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## keeperofthegood (Apr 30, 2008)

jstring said:


> Since we're on the pot subject. I'd like to ask if I can reuse the capacitors that run between my volume pot and tone pot when I put in the new pots?
> I play guitar but I have an old Odyssey Bass with Bartolini's that I use for recording and I am putting the new Alessandro pots in it. I think the capacitors are used as treble cut and they are black flat round things with 47ns written on them and rather than try to find a replacement for them since I know nothing about capacitors, can I unsolder them and resolder them to the new pots? Thanks
> jstring



Hey there, that is a good question. The easy answer is "Yes". However, I like the fuller answer so, lets give it a go:

When removing parts, you have to remember they were installed once. Their leads have been bent, maybe one or two or more times in being installed. This stresses them out. Stressed metal likes to break  so, you do need to be gentler in taking off parts than when you were putting new parts on in the first place.

Heat, as always, is as much a friend as an enemy, and if you over heat them while taking them off you could easily cook them. Yes, taking things off can involve more time than putting them on, and often, if the leads are long enough, it is easier and safer to clip them close to the original solder points instead.

47ns is British according to the reading on Capacitors I have done the past few weeks. There is a notation in science that 'most' electronics stick to. Grouping numbers in threes. Only, capacitors is one of those "exceptions". Instead of saying that 1uF (micro farad) is the same as 1,000nF (nano farad) we skip to the next break down and say 1uF is the same as 1,000,000pF (pico farad). It is an odd thing, skipping that middle name the 'nano'. However, the UK went ahead and decided to use it. So, instead of what you would expect to see on a part labelled for North America as either 0.047uF if it was fully typed out, or 473 which is the more modern means, it is labelled as it really is, 47nF minus the F because all capacitors are in an F of some value or other. 

That last digit, the 's' is maker dependent though there is a loose association with things like either temperature co-efficients or tolerances. The temp-coeff doesn't really mean a lot to guitars unless you plan on playing in front of the blast furnace at Stelco followed by an open air performance at Alert. Most room temps across North America are the same 18 to 22 centigrade, and even the hottest day outside is not as hot as 80 or 90 Centigrade nor is the coldest day outside that you would be playing your guitar likely to be colder than 32 below. As to tolerances, 20% apparently you wont hear a difference with 

So, the short answer again is "yes"  Just be careful with removing the old caps, and clipping the leads is OK and probably the safer way to go. The draw back to that is you end up with shorter leads which may be a NO GO in your re-install, so consider that one carefully first 

EDIT**

Of course if you are going from 250k to 500k or to 1meg there will be a change in tone. How that works, I am not an expert on, so I leave that to the other wiser heads


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## jstring (Nov 11, 2009)

Thanks Mr. Good, that was some really useful info. Now I know too that if I screw up, I can replace them with 0.047uf. I had been looking at capacitors on electronic websites and could never find 47ns and really wanted to make sure I didn't alter the bass since it has some history. I am staying with 250's so that won't change. So thanks again..........now I gotta see about canceling that gig at Stelco..................
j.string


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## keeperofthegood (Apr 30, 2008)

you are welcome.

One thing you may wish to consider. Because there is variation in capacitors, and because they can value drift over time, when you have your caps half removed, measure their values with a meter. Most new digital meters can do cap values so getting one should not be too hard. However, this will give you an idea how close to the stamped value your caps are. If you need to replace them, because at a later point they just fall apart or the get lost, or misplaced or something , then you will have a record of what they were to begin with for sure. I would even suggest using a china marker or similar and jotting the info down on the inside of the cover  so it is always with the guitar too.


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## Jim DaddyO (Mar 20, 2009)

It's funny that the Seymour Duncan wiring diagrams use soldering to the pot case. You would think that they would recommend star grounding..


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## Wild Bill (May 3, 2006)

Jim DaddyO said:


> It's funny that the Seymour Duncan wiring diagrams use soldering to the pot case. You would think that they would recommend star grounding..


Not really. They are copying a way that was proven to work. You won't get in trouble that way unless you make a change.

I'm not arguing that soldering to the pot case ALWAYS causes a problem!:smile: Just that it can, if things are not done right. Star grounding ALWAYS works, however!

I would also say that it's not always wise to believe that anything factory stock is always right. I've had to fix too many amps that had design flaws to ever believe that! Remember, there's always some "suit" from the marketing department who says "You engineers stop nitpicking and just ship the damn thing out! We have to make some money here!" That's why the first VibroKing models kept frying their reverb driver tubes. The problem was so bad and so obviously a bad design that Fender had to do a recall, which cost them a fortune.

Once again, I suggest going to this site:

http://www.guitarnuts.com/index.php

It explains it very well and far better than me. 

Or, you can just be a trusting little lamb and copy without understanding...

That's what makes us techs more money!:smile:

:food-smiley-004:


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## Jim DaddyO (Mar 20, 2009)

More pearls of wisdom! Thanks Bill, as always you are right on! From working in a few factories I can relate to the "just get them out the door" mentality.


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