Cap/tone pot combination suggestions

[Inflames626]

Hey guys,
This one has been done a million times but I have some pretty specific requirements so it won't be an open-ended cork sniffing contest as far as exotic cap materials, values, etc.

I normally don't use a passive tone pot. I dislike them as I find them imprecise. But in my guitars that have them I often use them at 10 on the bridge position (fully bright) and 1 (fully dark) on the neck position to darken a neck pickup if it is too bright. In this way I can have both a warm and bright neck pickup depending on how I dial it in.

I don't go in between very often on the tone knob but when I do I would like things to be somewhat even and gradual with a wider (darker) sweep.

So far in my guitars (which are all humbuckers to this point) I have used 500k linear pots with a .022 uf cap for tone. The cap isn't anything special--those little red ceramic caps that come in import guitars. I prefer to use them because they are small.

Using linear pots with a .022 cap I have noticed that the pickups don't go quite as dark as I would like, and I only hear a serious change from about 3-1 on the tone knob. The rest of the change is very slight throughout the rest of the taper--almost imperceptible.

Another guitar that I have has a .022 uf cap but an audio pot. The change seems more obvious but again the change seems crowded at the very end of the taper. However, the .022 uf cap seems to go darker on an audio pot than on a linear one. At least my ear notices it more. I thought this was because of the audio taper of the pot making it more obvious at the sacrifice of a more even, gradual sweep.

My hope is that going with a .047 uf cap on a linear pot will make the tone darker and the sweep wider and more gradual for more in between tones. I thought I would check this by running it past all of you. Again, it wouldn't be anything special. Just one of those little green ceramic disc caps that are in import guitars.

I do have .1 uf Orange Drop caps (don't remember the pot type) in a dual P BC Rich Warlock bass because I wanted to imitate a vintage bass and sound more like a flatwound/fretless bass on a roundwound fretted rock bass.

I made the mistake of recording bass lines with the tone knob all the way on 1 (dark) and I never got out of mud territory. I had to do a lot of fixing in post to get it to sit right in the mix.

So I have always been a little paranoid about my caps being too dark.

So, do you think going to a .047 uf cap with a linear pot will give me a wider, darker, more gradual tone response?

Thanks.

 

[GuitarStv]

The way a tone control works in a guitar is like a low pass shelving filter. Basically, there's a specific frequency that is set where the everything higher than it gets rolled off to ground. Capacitor value sets this frequency. So a large value capacitor like .047 will roll off some of the mid range and highs, a medium value like .022 will roll off mostly the highs, and a very small value like .010 or .005 will roll off only the very highest highs.

With the tone up full and 500k or higher pots, there's really no perceptible difference between capacitor values - you hear the difference when you're rolling things back.

People tend to hear smaller value capacitors as having a usable range for the tone pot because they only roll off the very highest highs - often these are frequencies that you don't want much of so it's OK to lose them. Bigger value caps eat some of your mid range so they kill the parts of the guitar signal that is most important, which tends to reduce the usable range.

 

[Inflames626]

Right, and what I'm hearing is highs being chopped off in a very small range of the knob.

I would like highs and mids to be more gradually chopped off through a wider sweep of the knob.

I would like the maximum (darkest) setting of the tone pot to be darker than what a .022 uf seems capable of.

 

[Inflames626]

I'm thinking using audio for a tone pot crowds most of the change at one extreme of the taper. This is fine for a volume knob (big volume swells with a short turn) but not what I'm looking for in a tone knob.

I'm thinking a linear knob would be more consistent and even throughout the the turn of the knob, and the .047 cap would cut into the tone more, making it darker.

So more darkness, wider, more gradual sweep.

 

[GuitarStv]

Right, and what I'm hearing is highs being chopped off in a very small range of the knob.

I would like highs and mids to be more gradually chopped off through a wider sweep of the knob.

I would like the maximum (darkest) setting of the tone pot to be darker than what a .022 uf seems capable of.

Yep, then you want a .033 or .047 cap. It's worth trying out several different values to see what works best for you - caps only cost a few cents each so it's easy to do with some alligator clips.

 

[Inflames626]

It's more my dreading swapping out the audio for linear pots--making sure the grounds are soldered on well and such since in the wiring scheme I have the tone knob is right before the jack.

It's not a big deal but I find my soldering joints from the hot and ground of the jack have to be done better than usual to prevent weird stuff from happening throughout the rest of the signal chain.

 

[Inflames626]

Also I must be getting old because reading the codes on those little caps can be hard even with a magnifying glass. I had to look them up just to make sure I had a .022 uf cap. But it does seem fairly consistent that red is .022uf and .047uf is green.

 

[Spaghetti Bolo]

250k no-load is my preference. Cap choice depends on the pickup and position.

Edit: Audio Taper duh.

 

[GuitarStv]

Also I must be getting old because reading the codes on those little caps can be hard even with a magnifying glass. I had to look them up just to make sure I had a .022 uf cap. But it does seem fairly consistent that red is .022uf and .047uf is green.

Use caps with the values written on them - makes life easier not having to look up codes. It doesn't matter what brand or type you get, they all work the same.

 

[Inflames626]

250k no-load is my preference. Cap choice depends on the pickup and position.

I thought using a 250k might be more appropriate for an HSS Strat or a bass. I would feel like I was giving up 50% of my tone sweep if I went from 500k to 250k.

Most of my pickups are fairly bright (Full Shred, PATB-1, Distortion, 498T, 500T). Their neck counterparts can be a little bright as well. Instead of grabbing another guitar with say a 57 Classic or an A2PN in it, I could just roll the tone knob down a little on those bright neck pickups.

 

[Inflames626]

Yeah I think mine have the little J622 codes on them or something. They are essentially OEM leftovers from import guitars that I never used.

 

[Clint 55]

2nd using an audio 250k no load. If you want to be able to focus in the dark part of the sweep, this is absolutely what to use. On 10 it is out of the circuit so there is no giving up the full range of the tone from bright to dark. You only give up the useless range of resistance from 500 to 250 that only colors and doesn't darken. Stay with the 22nf cap. If you want to be conservative about still having some range at the top then use an audio 300k no load. If you want the pot to taper down to dark more gradually then use a no load 250 or 300k linear taper.

 

[Inflames626]

Thanks Clint 55 . Like Aceman you've always got good advice.

 

[Clint 55]

No prob