Pots, capacitors and how to wire them

WindsurfMaui

Senior member
Messages
329

:help: So is there a link to an ongoing discussion on Pots, capacitors, resisters and how to wire them? I thought this would have been one of the easier issues, that it had been resolves what size pot for each type pick up, what size capacitor to each size pot and each how they should be wired. But when I did a search of the internet I see people playing mix and match with all the components plus a variety of ways for them to be wired together. So I assume there must be an ongoing discussion of how different combinations effect tone, volume etc. But i can't find it with my search. So if there is a thread please give me the link. Otherwise is there a consensus on what each combination does?  How to achieve a specific tone by adjusting the wiring?

I see that cagey uses 500K pots on all PU types with a .022 capacitor. What are other people using.
 

Sovereign_13

Senior member
Messages
311
Well, I almost gave you a huge explanation of how they all work together, but I don't think that's warranted.  If you're really interested, I can get into details.

A short version of how things sort of interact:

  • Higher-value (500k) pots bleed less treble to ground, and so are commonly used on "darker" pickups (humbuckers)
  • Conversely, lower-value (250k) pots bleed more treble to ground, and so are commonly used on "brighter" pickups (single coils)
  • For a given cap, a higher-resistance pot will roll off more treble when using the tone circuit
  • For a given pot, a higher-value cap will roll off more treble when using the tone circuit

Items 2 and 3 may seem contradictory, but realize that tone and volume pots always bleed a bit of signal to ground, even when they're turned all the way "up".  Hence, a lower-value pot will tend to muddy an already-dark pickup like a humbucker, even at full volume/tone.  0.022uF caps are pretty common all around, sometimes people will go up to 0.047uF.  This will increase the amount of treble roll-off you get when using the tone knob, good if you are trying to tame a particularly shrill pickup, or if your instrument range is below a normal guitar (baritone or bass).

All of this works on the principles of passive analog filtering.  The master tone knob is functionally a first-order low-pass filter.  Because passive filters require no power supply, it is not possible to "boost" any part of a signal beyond the level of the source - you can cut away bass, treble, or mids, but not add them.

Achieving a specific tone based on wiring is something you can spend years of your life on.  The thing is, there's so much variability between components, even with modern manufacturing (and especially with older manufacturing), that getting an identical sound by copying the wiring and component values is practically impossible.  You can, however, tweak an existing tone by playing with cap and pot values or adding resistors.  The Gibson Varitone setup is actually just a bunch of tone caps that are selected based on the position of the switch.
 

rgand

Senior member
Messages
5,934
I see Sovereign gave you a good rundown.

My personal preference for tone caps has been .047 but I never dial them all the way dark. On my latest build with the Broadcaster wiring I used a .033 cap because the neck pickup runs either no cap or full dark and .047 would be too much for that. Even at that, .033 is at the upper range of what sounds good to my ears. On tone pots in the future, I'll use .033 caps.
 

stratamania

Senior member
Messages
9,483
Sticky at the top of the Wiring part of the forum.

http://www.unofficialwarmoth.com/index.php?topic=281.0

Last post links to this written by one of the forum members. Read this first and then go back and check the other info linked to in the thread above.

https://www.seymourduncan.com/blog/the-tone-garage/guitar-wiring-diploma-course
 

WindsurfMaui

Senior member
Messages
329
Thanks to all for posting. I understand some of the basics but I see that there are so many variables that I thought there would be a running thread of those who are experimenting and sharing their results.  I have added capacitors in the past but see that people are adding resistors to the capacitors. Some are adding them to the hot lug of the pot and grounding the other leg to the top of the pot. Some are attaching one leg to the first lug and one leg to the second lug. Some are now adding the capacitor to the pick up itself. (???). In addition what would happen if you  added capacitors and then a tone boost circuit? There seems to be no end to what we can do to tone and shading and I want to try to catch up on the discussion.

I remember a long time ago seeing a 10 position  selector switch but never researched it. I see set ups with a lot of lug switches or push buttons adding in other variables. To me this seems to be  a new world experimentation. Maybe it is already old hat but it seems to be taking some of the variables that some get from their rack and putting it back into the guitar body. I haven't experimented with any of this so I don't know yet if I am a purist wanting to stick with the basic pot and capacitors or if this new way of electronics adds some real value. I thought there might be an ongoing thread of people who have done some of these experiments already and have reported back their results.

Kind of taking a stompbox and putting it into the control cavity. Which leads  me to also ask is their a thread on stomp boxes and what position in line works best for certain effects.
 

zebra

Senior member
Messages
498
Plenty of vids and website deal with pedal order.
Or...if you really want to, you could watch this:

https://www.youtube.com/watch?v=djA3ZG3dHj0
 

WindsurfMaui

Senior member
Messages
329
Here is a video of three different types of treble bleed wiring. Has anyone tried these? How do they differ in practice? I don't quite understand how wiring the resister to both legs of the capacitor is different than wiring the resister to only one leg of the capacitor.

https://www.youtube.com/watch?v=uxrFn1bekNQ

I watched another video (from a different person) who basically opened the control cavity and using long wires with alligator clips kept his guitar in working condition and connected different capacitors and resistors so demonstrate how his tone was effected. An interesting experiment. I may try a similar experiment on a guitar that has a rear control cavity. as anyone done this already? Are there any interesting options that I should include in my experiment? I have the a variety of capacitors but I don't think I have a good variety of resistors. Darn that Radio Shack for going out of business now that I need them!!!  :doh:
 

Cagey

Senior member
Messages
24,425
There's an interesting little treble bleed circuit by PMT available from Guitar Electronics that can save you a lotta rigmarole...
v_treb__93588.1470693258.500.400.jpg
v_treb_pot__33177.1481749559.500.400.jpg

Not only puts it all in a clean little package you can mount on your volume pot, it includes a little trim pot so you can adjust the thing to match your pickup(s). Seems like a good deal for $10.
 

WindsurfMaui

Senior member
Messages
329
I generally don't like putting computer "cards" into my guitar. But I think this may be a genius idea. I will definitely buy at least one for single coil and one for humbuckers to test and see what works best for all my pickups.  Thanks for the info.

I see they also had a Programmable Guitar Pickup Control System that is currently not being offered but waiting for the next generation of software. This system claims to be able to change pickups from series to parallel to in phase and out of phase. That sounds like a very interesting system. I hope the next version will be an app and that we can plug out phone into the system through the pickguard to make changes  rather than having to buy another box with a screen to run it.
 

Mark Anderson

New member
Messages
14
Cagey said:
There's an interesting little treble bleed circuit by PMT available from Guitar Electronics that can save you a lotta rigmarole...
v_treb__93588.1470693258.500.400.jpg
v_treb_pot__33177.1481749559.500.400.jpg

Not only puts it all in a clean little package you can mount on your volume pot, it includes a little trim pot so you can adjust the thing to match your pickup(s). Seems like a good deal for $10.


I am using stacked concentric pots for neck/bridge volume. Can I connect both of the stacked pots to a single treble bleed circuit, or do I need 2 circuits?
 

Cagey

Senior member
Messages
24,425
You will need 2. Even though the 2 pots are physically attached to each other, it's still 2 separate circuits.
 
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