A n00b asks about potentiometers and capacitors

astro · Post by **astro** » Mon Sep 22, 2008 11:46 am

I'm thinking of changing the pots and tone cap in my CIJ '69 RI mustang.

The stock pickups were terribly thin and anemic sounding (nothing like the delicious stock pickups in my '76 MIA 'stang), so in a fit of temporary insanity, I swapped them out for Lace Sensors (blue in the neck, red at the bridge). The blue sounds fantastic clean or dirty, but the red is a bit woolly. I've just got 250k pots for the tone and volume, and the tone cap is whatever Fender's standard value is for single coils.

I'd really like to get some more top-end definition out of the sound. Before I spend the big bucks on new pickups, I'd like to try 1 meg pots to see if that can cause an improvement. From what I understand (please correct me if I'm wrong, because I know nothing of how guitar electronics work), these would somehow bleed out less treble frequencies to ground, and instead send them to the output jack and then to the amp, after which they would tickle my eardrums with high-frequency joy.

So, do I need to change both pots to 1 meg to try this out? Or just the tone? Or is it the volume? And while I'm at it, what value of capacitor should I use? I don't have any clue what the values actually even mean on a capacitor, so anyone willing to help my n00bness would be appreciated greatly.

Post by **Mike** » Mon Sep 22, 2008 11:54 am

You've got the idea nailed. the cap bleeds treble to ground. It's value and the value of the pot create a low pass filter. Also the higher the pot value the higher the treble content of your signal with the tone on max because there is a "hidden" capacitance in the cable of your guitar which also bleeds treble to ground.

I would replace both pots with 1meg Audio/Logarithmic pots from Smallbear electronics and also get a smaller cap value while you're at it. a Mustang typically uses a 0.05 uF (microFarad) capacitor.

0.05uF is 50nF. or Typically 47nF.

I would get a 22nF and a 10nF cap and try them out. I would probably opt for the 22nF cap and the 1meg pots.

astro · Post by **astro** » Mon Sep 22, 2008 8:55 pm

thanks, dude!

Another question:
is there really a difference in tone with pots and caps from different manufacturers (assuming all values are the same) or is it just corksniffing? I've seen that really really cheap pots (like those in no-name guitars that cost $75 new) generally have really poor tapers, often being more like a rotary on/off switch instead of giving a gradual change in volume or tone. (perhaps these had a linear taper instead of an audio one?) But I've also seen that a lot of people change the pots in their Japanese fenders to American made ones with the same values. I would assume that Japanese pots and caps would be of a quality comparable to American ones, so I don't really understand why they would do this. The stock bits in my Japanese mustang all appear to do their jobs properly, so I don't see a point in changing them if they're just being replaced with ones with identical values.

Post by **Mike** » Mon Sep 22, 2008 8:58 pm

I think really cheap shit is going to be a pain, but there's no sense in spending silly money. A standard ceramic cap is fine but I use Mylar or multilayer ceramics in my pedals these days, they're just more solid to work with. Alpha pots aren't that expensive and they're excellent.

Will · Post by **Will** » Tue Sep 23, 2008 1:31 am

Alpha and CTS are both great - really natural tapers and very durable. They pay for themselves by not going all scratchy after 2 years.

Post by **Mike** » Tue Sep 23, 2008 7:17 am

CTS are fucking huge though - who needs that?

serfx · Post by **serfx** » Tue Sep 23, 2008 9:09 am

i've always enjoyed the tone out of my `65 stang
it's .05 with 250 k pots

and a rats nest of vintage wiring.

Will · Post by **Will** » Tue Sep 23, 2008 7:40 pm

Mike wrote:CTS are fucking huge though - who needs that?

I <3 huge pots.

Post by **Mike** » Tue Sep 23, 2008 7:54 pm

Lack of space in pedals? No thanks.

Too big to fit in Mustang routes? No thanks.

James · Post by **James** » Tue Sep 23, 2008 7:56 pm

I don't have much experience of CTS pots, but Alpha seem to be way better quality from the little I do. The TBX (CTS made) tone control I have actually came apart a little, and the volume pot isn't a hell of a lot better. Definitely not worth the premium.

astro · Post by **astro** » Wed Sep 24, 2008 1:16 am

Where can I buy Alpha pots (I'm in Canada)? Also, how do I know how a capacitor is made? With the different types of caps, am I correct in assuming that differences in construction essentially affect just the durability and longevity of the component? What brands are reputable? I've seen corksniffers spend huge dough on bootteekk caps, but I just want something cheap and durable.

Here's yet another question:
When I'm soldering the new pots, will I need flux paste for when I solder wires directly to the body of the pot? Or is it good enough to just use flux core solder? I ask this because I can't seem to find flux paste anywhere (and when I say "anywhere", I mean Radio Shack, because I don't know where else to look locally).

Will · Post by **Will** » Wed Sep 24, 2008 2:18 am

astro wrote:Where can I buy Alpha pots (I'm in Canada)? Also, how do I know how a capacitor is made? With the different types of caps, am I correct in assuming that differences in construction essentially affect just the durability and longevity of the component? What brands are reputable? I've seen corksniffers spend huge dough on bootteekk caps, but I just want something cheap and durable.

Here's yet another question:
When I'm soldering the new pots, will I need flux paste for when I solder wires directly to the body of the pot? Or is it good enough to just use flux core solder? I ask this because I can't seem to find flux paste anywhere (and when I say "anywhere", I mean Radio Shack, because I don't know where else to look locally).

Don't know where to find good pots in stores - usually smaller guitar stores that do a lot of repair work will have them. Caps are usually either ceramic (little flat round orange things) or polyester (green squares or yellow cylinders). Vintage Fenders used ceramic, most others use polyester. The difference in sound/durability is negligible compared to other factors. Ceramic may sound a little muddier in a tone circuit, polyester a little clearer (but it's extremely subtle). I've never needed flux paste - alpha pots in particular seem to solder very easily.

Ninja Mike 808 · Post by **Ninja Mike 808** » Wed Sep 24, 2008 2:27 am

astro wrote:Where can I buy Alpha pots (I'm in Canada)? Also, how do I know how a capacitor is made? With the different types of caps, am I correct in assuming that differences in construction essentially affect just the durability and longevity of the component? What brands are reputable? I've seen corksniffers spend huge dough on bootteekk caps, but I just want something cheap and durable.

Here's yet another question:
When I'm soldering the new pots, will I need flux paste for when I solder wires directly to the body of the pot? Or is it good enough to just use flux core solder? I ask this because I can't seem to find flux paste anywhere (and when I say "anywhere", I mean Radio Shack, because I don't know where else to look locally).

When I use lead solder, I usually scratch the pot's body, it seems to work better, even though it has flux in it.
When I use silver solder, nothing really works (even with the flux), but sometimes it sticks better to the parts I didn't scratch... There's supposed to be a protective coat on the pots, though, so be mindful of that.

I dunno if I should do this, but there's a thread at offset that lists a bunch of great sites to buy pedal supplies (and the like) from. If I shouldn't be promoting offset, lemme know...

serfx · Post by **serfx** » Wed Sep 24, 2008 6:46 am

astro wrote:Where can I buy Alpha pots (I'm in Canada)? Also, how do I know how a capacitor is made? With the different types of caps, am I correct in assuming that differences in construction essentially affect just the durability and longevity of the component? What brands are reputable? I've seen corksniffers spend huge dough on bootteekk caps, but I just want something cheap and durable.

i have no idea in montreal, but i did pick some up at long & mac for dirt cheap a while back, from teh repair department, i assume they have a location near you. if not i also go to this tiny shop in the middle of nowhere that hass them for about $2.50/each
so worst case scenario hit me with a PM and i'll grab some and mail them out.

i need to go pick up some resistors in the next couple days so its not even out of the way.

serfx · Post by **serfx** » Wed Sep 24, 2008 6:54 am

remove double post

Post by **Mike** » Wed Sep 24, 2008 7:51 am

SmallBear.

http://www.smallbearelec.com/home.html

Two of these (1meg)
http://www.smallbearelec.com/Detail.bok?no=555

One of them
http://www.smallbearelec.com/Detail.bok?no=518

One of them
http://www.smallbearelec.com/Detail.bok?no=517

done.

astro · Post by **astro** » Wed Sep 24, 2008 9:44 pm

serfx wrote:
astro wrote:Where can I buy Alpha pots (I'm in Canada)? Also, how do I know how a capacitor is made? With the different types of caps, am I correct in assuming that differences in construction essentially affect just the durability and longevity of the component? What brands are reputable? I've seen corksniffers spend huge dough on bootteekk caps, but I just want something cheap and durable.
i have no idea in montreal, but i did pick some up at long & mac for dirt cheap a while back, from teh repair department, i assume they have a location near you. if not i also go to this tiny shop in the middle of nowhere that hass them for about $2.50/each
so worst case scenario hit me with a PM and i'll grab some and mail them out.

i need to go pick up some resistors in the next couple days so its not even out of the way.

Thanks dude!

There are no Long & McQuade stores in Quebec. Most of the guitar stores here want something like $12 for a pot, so I'm going to not bother with the local retail route.

astro · Post by **astro** » Wed Sep 24, 2008 9:48 pm

Mike wrote:SmallBear.

http://www.smallbearelec.com/home.html

Two of these (1meg)
http://www.smallbearelec.com/Detail.bok?no=555

One of them
http://www.smallbearelec.com/Detail.bok?no=518

One of them
http://www.smallbearelec.com/Detail.bok?no=517

done.

Thanks!

How does the tone change with the different cap values? Will they sound the same with the tone pot maxed out and just have a different taper, or is it different sounds altogether with the tone cranked?

Post by **Mike** » Wed Sep 24, 2008 10:18 pm

The lower the cap value the brighter it will sound at max, and the treble will be retained for longer down the sweep.

ElCapitan · Post by **ElCapitan** » Thu Sep 25, 2008 9:18 pm

Is it possible to have two two pots? One a high-pass and one low-pass and when both are fully down there's no sound? I always thought that would be cool, eq wise.