volume pots,tone pots,tone caps on diy pickup

[therizky]

hi..

i just finished winding and building three single coil pickup for my strat,what i wanna ask is how do i determine that volume pots,tone pots and tone caps?

original strat are using 250 k for tone,volume and 0.022uf for tone caps,but i'm not sure to use the same for my diy pickups,cos i already try it and it  sounds different when i just connect it to the jack(not connected to pots or anything)

so,please help me and give me some suggestion

[Derringer]

when you say it sounds different connected straight to the output jack .... are you saying that it's different from a manufactured pickup that is also connected straight to the output?


if it were me, I'd start with 250K's and 0.022uf, see what that sounds like, and then make adjustments from there.

You could even wire a switch between vol pot lug 1 to ground that either shunts the lug to ground (normal) or a 220k-270K resistor to ground so that you could get an "idea" of what a 500K volume pot would sound like .. etc etc

[BAARON]

Adding volume and tone controls will start to eat into the treble frequencies and a little bit of output power.  Pickups will always sound the brightest and most muscular when they are connected directly to an output jack with no controls.

- The bigger the volume pot, the closer you'll get to that sound when the volume is turned up to 10.  If it's too small, you'll lose more treble and some output power.

- The bigger the tone pot, the closer you'll get to that brighter the sound when the tone is turned up to 10.  If it's too small, you'll lose too much treble.  A bigger tone pot will be brighter when it is turned to 10, but will not affect the tone control's response when turned down to 1.

- A small tone cap will let more highs through when the tone control is at 10 and when it is at 1.  I like using a 0.01µF with 500k audio pots for humbucker tone controls, or something as small as 0.0068µF with a 250k audio pot for single coils.  I always found that turning my tone knob all the way down was way too lifeless and dark, so this makes 1 on the knob a little more lively and clears things up at 10 too.  A lot of my customers have really enjoyed this simple mod.


About your pickups: have you measured their impedances yet?  If so, what are they?

[ForcedFire]

I think single coils usually use 0.047uF. 0.0068uF sounds too small. Just get some alligator clips and try a few out.

[BAARON]

No, most modern Strats Usually use 250k and 0.022µF, and most humbucking guitars use 500k and 0.047µF.  It's essentially the same frequency response when you're at 10 on the knob, but the humbucker wiring is darker when you turn the knob to 1.  (Check the wiring diagrams at the Seymour Duncan or Fender websites if you don't believe me about the 0.022µF/250k pairing on modern Strats.) 

Changing from 0.022µF to 0.0068µF actually isn't a drastic change: it only moves the treble roll-off frequency up about an octave and a half.  10 on the tone knob will sparkle more and be a bit more lively, and 1 on the tone knob will still be fat and dark, but it'll sound like you're playing with fewer pillows piled on top of your amp.

Every time I have a non-technical customer who tells me, "I want new pots in my guitar to improve the tone," I change the caps at the same time, and if they come back with comments about their new tone, they're always positive.

[sean k]

You can use a smaller tone pot so it does cut hghs but cut the track on the carbon at 10 so when its on full the wiper is disconnected from 95% of the track and then have a ground lift switch on the volume pot.

To do this take apart the tone pot and file across the circular track about 3 - 4mm from the end so the wiper and input tab are not connected to the rest of the track when your on 10. Then as you bring in tone the wiper crosses the cut and the tone control acts like a normal lowpass. As for the Volume pot the idea is that wherever it's set by lifting the ground you'll only be going through the distance btween the input and the wiper which then becomes a rheostat.

[Mark Hammer]

I will not recommend anything since I do not know the wound impedance or DCR of your pickups, or what sort of tone you like.

However....

If you like to be able to get bright tone, or if the pickups happen to have a somewhat dull tone or are overwound, you may want to go with 500k volume pots, since they will help to retain whatever highs are in the pickups...at least when volume is set to between 7 and 10 turn it down below that and ALL pots affect the tone).  If you prefer a "rounder" tone, or have very bright pickups that need to be tamed a bit, or a very bright amp that needs to have treble shaved off from the input signal, then you may want the deliberate strategic tone-sucking of 250k volume pots.

There is a lot of legend about volume pots, and people keep forgetting that the basic guitar wiring of single-coil pickups was established when: a) pickups were under rather than overwound, so they had more treble to begin with, and b) your typical Fender picker would be plugging into a Fender amp, which would be very bright.  Guitar electronics were established in light of the tonal preferences, and electronic likelihoods of the time.  If what was established then works for your needs now, great, but if it doesn't there is no reason why you have to observe the orthodoxy.

One example of "the orthodoxy" is the assumption that whatever you do for tone control on the neck you also do for tone control on the bridge.  Okay, do me a favour.  Right now, phone up all the friends you have that switch to their bridge pickup when they want a mute dull sound.  That didn't take very long, did it?  Yet for 50 years, manufacturers have been sticking the same damn cap value on the bridge that they stick on the neck.  Why?  The sheer dead weight of precedent.  My advice is to use a cap for the bridge tone control that is perhaps 1/3 - 1/2 the value of that on the neck.  So if you have .022uf on the neck, then stick a .01uf on the bridge.  A traditional Strat uses a single cap for the two tone pots.  Use two different caps, one for the neck and another for the bridge.

Note that tone pots always bleed treble, unless they are taken completely out of circuit.  If you can't take them out, then you want their bleed to be negligible or useful.  So, a 500k volume pot can benefit from 250k tone pots if the volume pot lets a little too much treble through.  Vice versa as well (a 500k tone pot can help a 250k volume pot).

[zombiwoof]

No, most modern Strats Usually use 250k and 0.022µF, and most humbucking guitars use 500k and 0.047µF.  It's essentially the same frequency response when you're at 10 on the knob, but the humbucker wiring is darker when you turn the knob to 1.  (Check the wiring diagrams at the Seymour Duncan or Fender websites if you don't believe me about the 0.022µF/250k pairing on modern Strats.) 

Changing from 0.022µF to 0.0068µF actually isn't a drastic change: it only moves the treble roll-off frequency up about an octave and a half.  10 on the tone knob will sparkle more and be a bit more lively, and 1 on the tone knob will still be fat and dark, but it'll sound like you're playing with fewer pillows piled on top of your amp.

Every time I have a non-technical customer who tells me, "I want new pots in my guitar to improve the tone," I change the caps at the same time, and if they come back with comments about their new tone, they're always positive.

I have to disagree with a couple of your points, humbucker guitars don't use .047uf tone caps, they generally also use .022.  Vintage Gibsons used .022 for both pickups, many guys these days use .022 for the bridge and .015 for the neck.  .015 rolls off less treble at the lowest position of the tone knob, so the tone doesn't go into mud territory when you turn the tone down.  I also don't believe that a different tone cap will change the tone when the tone knob is on 10, IMO it will only change how much treble is rolled off as you turn down the tone control.  The one thing that will affect the overall brightness is a change in volume pot value, a 500k pot will make a guitar brighter than a 250k pot.  And as some have noted, you can use a No-load pot on the tone which cuts the tone control out completely when it is on 10, Fender makes a 250k version, you can find 500k versions on Ebay or make one yourself as another poster has said.

Al

[Electric_Death]

I push 2 meg pots on everyone.
It eliminates the need for a "volume kit" for starters and you get the full potential out of your pickups. It's a looser, more open sound which isn't for everyone since 250 and 500 K pots give a more focused sound but I've yet to own a guitar that after 2-3 months, I couldn't stop myself from performing the mod.

With modern pickups, all taper without issue and contrary to what many will say, even a 2 meg linear pot on a 4k ohm single coil pickup will give noticeable volume boost/cut at every point-many claim you'll get to about 6-7 and deliver full volume making the 10 position useless but this just isn't true. You'll also realize aside from the wide open output, your treble doesn't get shunted at nearly any volume setting. Now look at what a volume kit is. Generally a 100K resistor and small value cap wired parallel on your volume knob, thus turning it into about a 60-80K pot!

"Volume kits" don't make a bit of sense.

The issue with a 2 meg or 1 meg pot is however that the shafts are never long enough for anything but the pickguard.
Every body I've mounted them in required thinning out the electronic's cavity with my dremel or sometimes router and you'll find yourself having to go fairly thin though in my opinion, it's well worth it. Better pinch harmonics, smoother volume taper and an all around wider, looser, stronger and more responsive signal from your pickups. I use 2 meg linear pots so the taper is more even and smoother than audio log and if you want the tighter, focused effect of a smaller value, well you simply roll the volume back. 

It simply gives pickups more life and you truly hear the wood resonating where as with 250 and 500 K, you don't.

[Mark Hammer]

Let me be perfectly clear, the advantages of higher-resistance pots occurs only when the volume is on max.  Once you turn down from there, increasingly larger amounts of resistance are placed in series with the pickup, and the amp sees it as just another high-impedance source...much like the other side of the wiper.

I personally like higher value volume pots, but if you're the kind of player who often has the volume turned down for some reason, then you will benefit by use of lower-resistance pots.

[BAARON]

I have to disagree with a couple of your points, humbucker guitars don't use .047uf tone caps, they generally also use .022.  Vintage Gibsons used .022 for both pickups, many guys these days use .022 for the bridge and .015 for the neck.  .015 rolls off less treble at the lowest position of the tone knob, so the tone doesn't go into mud territory when you turn the tone down.  I also don't believe that a different tone cap will change the tone when the tone knob is on 10, IMO it will only change how much treble is rolled off as you turn down the tone control.  The one thing that will affect the overall brightness is a change in volume pot value, a 500k pot will make a guitar brighter than a 250k pot.  And as some have noted, you can use a No-load pot on the tone which cuts the tone control out completely when it is on 10, Fender makes a 250k version, you can find 500k versions on Ebay or make one yourself as another poster has said.

Al

- You can't straight-up say humbucking guitars "don't" use 0.047µF, because some do, and anybody silly enough to wire their guitar off a Seymour Duncan wiring diagram will use them too.  I suppose I shouldn't have said "most" though, because I haven't performed a statistical analysis...  All I know is that after servicing more than half a thousand guitars, I've seen more than a few humbuckers wired up with 0.047µF caps.

- Indeed, a smaller tone cap will keep it from getting too muddy when you turn the tone pot all the way down.  You suggested 0.015µF (which subtly places the cutoff frequency about a 5th higher than a 0.022µF cap will), I suggested 0.0068µF (only one octave higher than the 0.015µF, but a noticeably less subtle change)... both work.  I use tone pots ranging from 0.0068µF to 0.01µF in my own guitars, usually depending on what I have lying around.

- After doing some math I have to admit that you're absolutely right: a smaller tone cap won't affect the treble roll-off when the tone knob is cranked up to 10 enough to be noticeable by the human ear.  My mistake.

- Not just the volume pot: the size of the tone pot will also have an effect on tone when it's turned up to 10, because the tone pot is in parallel with the volume pot: with standard wiring, they both go from the pickup output to ground (the tone pot does so through the tone cap, which adds some frequency-dependent impedance), and so the impedance the pickup sees is the result of the two pots in parallel.  Thus, changing the value of the tone pot will affect the sound when the controls are wide open just like changing the value of the volume pot will.


I wonder when the original poster is going to get around to reading this so they can let us know the impedance of their pickups and what they're trying to do with their guitar tone?

[Electric_Death]

Let me be perfectly clear, the advantages of higher-resistance pots occurs only when the volume is on max.  Once you turn down from there, increasingly larger amounts of resistance are placed in series with the pickup, and the amp sees it as just another high-impedance source...much like the other side of the wiper.

I personally like higher value volume pots, but if you're the kind of player who often has the volume turned down for some reason, then you will benefit by use of lower-resistance pots.

I don't see a down side.
I cut my volume frequently and have no issues.

Ah an in regards to tone caps, what about lower value tone pots?
The taper of 500 and 250 k pots is pretty dreadful IMO. I installed a 100K pot as my tone control in my favored guitar(which is currently deceased) and the taper is much more dynamic or simply, gradual.

[BAARON]

I installed a 100K pot as my tone control in my favored guitar(which is currently deceased) and the taper is much more dynamic or simply, gradual.

E.D., you realize that because the tone control (100k+0.022µF) and the volume control (2M) are in parallel (from pickup output to ground) that your pickups don't see a 2 meg impedance, right?  They see 2M || 100k+0.022µF = ~175k@80Hz/100k@1280Hz (lowest and highest notes on the instrument), which is actually lower impedance than 500k || 500k+0.022µF (270k@80Hz/250k@1280Hz).  Not only it is a lower impedance overall, but even with the tone control turned up to 10, there's significantly more high-end rolloff than with 500k pots for tone and volume.  It's slightly higher impedance on a low E than using 250k pots (145k@80Hz/126k@1280Hz), but the 2M/100k combination is still darker at the top of the guitar's range (due to its lower impedance and thus loss of treble frequencies).

[zombiwoof]

Let me be perfectly clear, the advantages of higher-resistance pots occurs only when the volume is on max.  Once you turn down from there, increasingly larger amounts of resistance are placed in series with the pickup, and the amp sees it as just another high-impedance source...much like the other side of the wiper.

I personally like higher value volume pots, but if you're the kind of player who often has the volume turned down for some reason, then you will benefit by use of lower-resistance pots.

I don't see a down side.
I cut my volume frequently and have no issues.

Ah an in regards to tone caps, what about lower value tone pots?
The taper of 500 and 250 k pots is pretty dreadful IMO. I installed a 100K pot as my tone control in my favored guitar(which is currently deceased) and the taper is much more dynamic or simply, gradual.

The value of the pot has negligible effect on the taper, there are many different 250k and 500k pots available today that have tapers that are customized for electric guitars, such as the RS Pots, the DiMarzio, Hamer, etc.   A 100k pot is going to darken the tone substantially when compared to a 250 or 500, but if it works for you, then it's cool.  Gibson puts 300k linear volume pots on their production guitars, which I absolutely hate (and I'm not alone in this, there is a whole industry built around people changing out those pots in Gibsons).  A good 500k pot will usually open up the sound of a standard humbucker, why Gibson uses those 300k pots is beyond me.  And the linear taper is terrible IMO, especially if you use distortion.  As you roll the volume down, there is little effect until you get to 1 or 2 on the knob, then the volume abruptly shuts off.  I think a good audio taper pot is preferable here, and as I said there are different tapers in the audio range to choose from.

Al

[Electric_Death]

Let me be perfectly clear, the advantages of higher-resistance pots occurs only when the volume is on max.  Once you turn down from there, increasingly larger amounts of resistance are placed in series with the pickup, and the amp sees it as just another high-impedance source...much like the other side of the wiper.

I personally like higher value volume pots, but if you're the kind of player who often has the volume turned down for some reason, then you will benefit by use of lower-resistance pots.

I don't see a down side.
I cut my volume frequently and have no issues.

Ah an in regards to tone caps, what about lower value tone pots?
The taper of 500 and 250 k pots is pretty dreadful IMO. I installed a 100K pot as my tone control in my favored guitar(which is currently deceased) and the taper is much more dynamic or simply, gradual.

The value of the pot has negligible effect on the taper, there are many different 250k and 500k pots available today that have tapers that are customized for electric guitars, such as the RS Pots, the DiMarzio, Hamer, etc.   A 100k pot is going to darken the tone substantially when compared to a 250 or 500, but if it works for you, then it's cool.  Gibson puts 300k linear volume pots on their production guitars, which I absolutely hate (and I'm not alone in this, there is a whole industry built around people changing out those pots in Gibsons).  A good 500k pot will usually open up the sound of a standard humbucker, why Gibson uses those 300k pots is beyond me.  And the linear taper is terrible IMO, especially if you use distortion.  As you roll the volume down, there is little effect until you get to 1 or 2 on the knob, then the volume abruptly shuts off.  I think a good audio taper pot is preferable here, and as I said there are different tapers in the audio range to choose from.

Al

Well, I'm running 2 meg linear pots on I think nearly every electric guitar I own...which is a bit of an obscene number.
In contrast to stock, audio taper 500 and 250k pots, the volume cut with the 2 megs be it with humbuckers or single coils is much smoother and more even. There is absolutely no abrupt jump what so ever-it's completely linear.
Alpha 2 meg linear pots from Mouser.

Even with really low impedance single coils like my 4 k ohm telecaster neck pickups, the transition is very smooth and even and in fact, I think audio taper give the abrupt jump in volume in contrast to the linear. Audio taper is at about 50-60% before it suddenly enters into the home stretch, nothing gradual about it. Maybe it's just me but I really doubt it. Try for yourself and you'll see what I mean. They deliver a much more dynamic and even taper. I have 2 Douglas Rhoad's style V's. I left one with the stock volume, installed a 2 meg in the other, this all being before changing the pickups and other mods. The stock audio taper pot tapered for $#!+ in comparison. It gave a more focused and tighter sound but ultimately lacked breathing and life.

For me, the proof is in the pudding

[BAARON]

You might want to read the post I left you, about what the 100k tone pot is doing to the impedance of your 2M volume controls.

[Electric_Death]

You might want to read the post I left you, about what the 100k tone pot is doing to the impedance of your 2M volume controls.

I did but wide open it has no load and it's only one guitar out of my obscenely large collection that all run 2 meg volume pots.
The rest are all likely equipped with stock 500k or 250k tone pots which I fiddle with off and on. The guitar with the 100K tone pot has some very hot pickups in it that I modded by installing incredibly large cap screws in place of the stock as well as a magnet change which gives a really cool natural compression effect without having any noticeable effect on sustain. The down side is the neck started to twist as a result of the fingerboard peeling off which I ultimately removed and will hopefully successfully replace sometime soon. Not a job I'm looking forward to and it's a very thin width neck-through guitar probably Stratocaster scale. I think the warp factor is most common with thin depth neck-through as I've been hearing this claim since I was a child and didn't even play guitar.
That 100K pot is the least of it's worries!

Anyway in regards to taper, I think audio taper is dreadful compared to linear. It lacks dynamics because the changes are so abrupt and out of curiosity, did you notice what I pointed out about the oh so popular volume kits?

The popular value is 100 K thus reducing a 250-500k volume pot to something like 60-80K resistance.
Meanwhile the 2 meg pots don't suffer the treble issue making a "volume kit" even more useless than it already is.
I bought some "volume kits" from Fernandez many moons ago and installed them on my stock pots, they made audio taper, taper even worse. You were hitting full volume at about 50% open and from there on there was absolutely no difference. I tried a few different R and C values but it really didn't make too much of a difference.
I'll probably never own more than a few guitars with low value pots. I try and after a while just can't take that "shunted" sound they have.

[BAARON]

You might want to read the post I left you, about what the 100k tone pot is doing to the impedance of your 2M volume controls.

I did but wide open it has no load and it's only one guitar out of my obscenely large collection that all run 2 meg volume pots.

I did read your "volume kit" post.  I believe it said: "Now look at what a volume kit is. Generally a 100K resistor and small value cap wired parallel on your volume knob, thus turning it into about a 60-80K pot!"
If you haven't noticed, your tone control is also a 100k pot with a small cap, wired in parallel with your volume pot.  You won't get the benefit of a 2M volume pot if you have a 100k tone pot wired in parallel with it.  The size of your tone pot has just as much effect on the output of the guitar as the size of your volume pot does.

Notice that the tone pot is not a voltage divider.  It is just a variable resistor between your guitar's signal and ground, with a cap in the way (and a cap is basically just an impedance source that changes value depending on frequency).  This means that a small tone pot is essentially a large tone pot that has already been turned down (to make its resistance smaller).  This means that when you use a 100k tone pot, it is like using a 500k audio taper tone pot that only goes from 1 to 4.5!

Now what does the pickup see?  The output impedance of the pickup goes into the input impedance of the tone and volume controls.  (You might want to read http://www.muzique.com/lab/imp.htm because it's a simple, handy explanation of impedance.)  Their combined impedance acts like a voltage divider for your pickup's impedance: R2/(R1+R2) = how much of your pickup's signal (at any given frequency) gets past the controls and moves on to your effects/amp, where R1 is the pickup impedance (a complex value that takes the pickup's inductance and DC resistance into account, as well as coil capacitance but I won't get into that) and R2 is the combined impedance of the tone and volume controls.  (Note that the tone control's impedance changes with frequency, due to the presence of the tone cap.  Look up capacitor reactance if that doesn't make sense to you.)  It's a little more complex than that because pickups are not simple things, but that's the general idea.

This means that with a 12k/4.5H humbucker (moderate output) and 2M/100k/0.022µF controls, you'll get about 93% of a low E coming through and 68% of a 24th fret high E coming through, assuming I did my math right.
Meanwhile, with 500k/500k/0.022µF controls, you'll get 95% of a low E, and 84% of a 24th fret high E.  The output level on the low frequencies is basically the same, but the high frequencies are being attenuated 16% less... simply because it does not have that 100k tone pot.
If you had 2M/2M/0.022µF controls (and thus the benefits of actual high-impedance controls), you'd get 99% of your low E and 95% of your high E.  For the high E, that's 11% better than the 500k pots, and 27% better than your 100k tone pot gives you.

And that's just the fundamental tone of the notes... that's completely ignoring the upper harmonics of each pitch.

Using a 100k tone pot renders a 2M volume pot pointless.



Regarding your fingerboard that needs replacing: you can determine your scale length by measuring from nut to 12th fret, then doubling that distance.  If you need to find a new fingerboard, www.stewmac.com and www.lmii.com both sell pre-slotted/pre-radiused fingerboards that you could buy, cut to size, carefully clamp and glue in place, and fret yourself.  Make Your Own Electric Guitar by Melvyn His%^&* is a good how-to book that will walk you through the process.  I would recommend it before other electric guitar building books.

[Electric_Death]

I completely disagree as the equations say one thing, the performance says another.
I am aware of the load changes and drastic change in impedance due to the way the loads stack up in parallel however, there are numerous factors left out of that equations, specifically the pickups voltage efficiency at any given frequency. Knowing that both pickups are 16.5k each still tells us very little in that regard. With something like an alnico magnet, which in truth isn't the best choice for high output pickups, I might be at about 85% from the 6th string and 65% from the 1st. With something more powerful like fresh ceramic magnets, I might be at 90% from both E's as well as everything in between. The primary missing factor is voltage frequency all across the scale.
In contrast to the 500k stock pot with that 100k tone, the 2 meg gave a lot more output even compared to my guitars with the same pickups running stock 500k volume and tone pots.

Even running a 2 meg pot with a 500k tone, the difference in output from any given pickup I own is vastly greater than 500k pots for both controls. In fact there's no comparison in frequency output or sheer volume. The 2 meg 500 k setup tramples all over the dual 500k. Also, I've gone with dual 2 meg for volume and tone, this renders the tone basically useless as it does nothing until you have the pot almost completely open. I also know that without knowing the actual voltage frequency, those equations you referenced are incredibly misleading and inaccurate in a very important sense.
You said it yourself, pickups are not simple but complicated devices and the factors you based your claims on don't factor in some very crucial attributes to actually scale the output my amps and pedals are seeing.

And if it makes you feel any better, I checked and while the guitar is in the zombie yard, I had pulled the 100k pot not long after installing it and put the stock 500k tone back in and simply forgotten. I'm also not big on fiddling with controls when I'm hitting an 8 finger arpeggio or inverted arpeggio that spans 5-6 octaves, about 40 notes and is hitting well over 200bpm. For that reason, I've put together a simple tone stomp box that kicks in a treble bleed cap when I desire.

As far as fingerboards go, those are some pretty weak resources lol.
I have a custom resource that will build anything I need including custom inlay work and fretting for about double the price of stewmac's board that have radius, no inlays and no frets. Why anyone would want to do so much work only to replace it with a radius fingerboard is crazy to me. Unless you're playing finger picked arpeggios in front of King Arthur, a radius is absolutely useless to a modern player. I enjoy having my action absurdly low while still being able to bend my E and B strings without them fretting out.
So thoughtful of you to talk to me like I'm ignorant and don't know anything, meanwhile you referred me to about the worst suppliers possible! lmao
You literally referred me to the "used car salesman" of luthier suppliers.
Kid if I didn't know how to measure the scale of a guitar, I sure as hell wouldn't be doing so much work on guitars now would I

[BAARON]

I'm going to leave this thread, as I prefer not to argue with trolls who misuse words like "voltage frequency" without knowing what they mean, don't listen to others who are trying to explain the concepts rationally, and straight up insult them for trying to be helpful.

I'm not even going to point out all the wrong things you just said in your post, because it would be a waste of my time.  I think they should speak for themselves.

I'm done with you.  Thank you for making DIYstompboxes a lot less pleasant for me and a handful of other users who have had to deal with your constantly inflammatory posts recently.