Treble bleed caps(or whatever they are called)

[Laroosco!]

Will they work on humbuckers??

I have an Epi Dot that I've done some upgrades and it is just about perfect except that it gets super muddy when I use the volume knobs.

I've used volume kits on my Strat and Tele with great success but have never heard of anyone using one on a humbucker guitar.

Any help is appreciated

Thanks

[big mike]

Yup. PRS Uses the 180PF on their volume pots with the 5 way. Works for me!

[erksin]

Yep - they work great on HBs...

[Laroosco!]

So you need different values or will the same kit I used on my Strat work?

This is what I have on my Strat
http://www.acmeguitarworks.com/Volum...0K-P87C13.aspx

[pfflam]

Originally posted by Laroosco!
So you need different values or will the same kit I used on my Strat work?

This is what I have on my Strat
http://www.acmeguitarworks.com/Volum...0K-P87C13.aspx

And ,might I add to that question by asking that if you wire up a 500k volume pot for a humbucker will it also work with SCoils in the same guitar if they are wired with resistors of 240+k to make the volume values proper for them?

Does that question make sense?

I want to have a Humbucker or like in a Tele with two other Single coils so I want to have the 500k pot work for the HB but have resistors twixt it and the SCs so that they don't distort or get too trebbly?
Would this then work witht the 'trebble-bleed' fix?

[Clorenzo]

Yes you can use the 680pF/220k combo with humbuckers too. In fact that keeps the frequency response fairly constant as you turn the volume down, while the single 180pF cap as used by PRS actually increases slightly the treble.

BTW hats off to Acme for openly admitting that "There is nothing special about these components, you can buy them from Radio Shack for 50 cents or less (we're guessing)." Refreshingly honest compared to those ripping off people with components supposedly "specific for guitar" and hence 10 times their real price.

As for pfflam's sc/hb question, you should put those 240k resistors between the hot wire of the sc's and ground, not between them and the pot. And yes, the bleed circuit on the 500k pot will still work fine.

[Richard Guy]

Try soldering a .001uf disc cap across the middle lead and hot lead on your volume pot. It will preserve your treble as you decrease the volume. No more mud.

[Southbay Ampworks]

A .001 microfarad and 150K resistor does the same trick on a humbucker. Here's how to wire it, too. Different values change the pot taper slightly as well.

http://scumbagamps.com/68lpc/volumepotmodpic.jpg

[erksin]

Originally posted by Richard Guy
Try soldering a .001uf disc cap across the middle lead and hot lead on your volume pot. It will preserve your treble as you decrease the volume. No more mud.

That's what I used - works great...

[Tone_Terrific]

Kinman pups has a decent explanation and solution at the site.
Adjust the values to taste. I prefer this sort of series arrangement myself and have used it for a long time, hb or sc's.

[Clorenzo]

If you guys want to see what each combination of R and C values does to the frequency response of the pickup, download this Excel spreadsheet (warning: for it to work you have to go into Tools -> Add-Ins... and activate "Analysis TookPak" and "Analysis ToolPak VBA"):

www.harryj.net/voltone.xls

adjust the pot values, the pickup parameters (the default ones are for a PAF, for a typical single-coil try R = 6k, L = 2.8H, C = 60pF) and play with the "Bleed R" and "Bleed C" values (to simulate no resistor, give it a very large value like 100000000). For those who don't want to bother, as you turn the volume down:

- 220k / 680pF basically preserves the frequency response of the pickup:



- 150k / 0.001uF is very similar, with the peak slightly higher:



- 180pF moves the resonant peak up in frequency and increases slightly its amplitude, so the sound changes to more of a single-coil character:



- 0.001uF keeps the resonant peak roughly where it is, but increases its amplitude a lot, so if with the volume at 10 the peak is about 5 dB, with the volume at 4 it's about 18 dB:



- For completeness, here's the response without the bleed circuit:

[Old Tele man]

Excellent! -- nothing like a few PICTURES to spare us thousands of WORDS!

[Jon Silberman]

Originally posted by big mike
Yup. PRS Uses the 180PF on their volume pots with the 5 way. Works for me!

Interestingly, as an experiment, I recently upped the cap on my '86 Custom to 1000 pf. The experiment was successful - rolling down the volume on the humbucker settings produces very single-coilish tones (rolling down the volume on the single coil settings, on the other hand, sounds awful but I've never found much of a need to do that so it doesn't bother me).

[KaBudokan]

Just wanted to say "Thanks!" to Clorenzo for this app. I was having trouble finding certain capacitor values, so using the app you linked to I was able to come up with something that works very well using stuff I had here in the house. Here's the frequency chart:

Values: 270k resistor with a 470pf cap

[John Phillips]

So far no-one has mentioned the single most important factor - the cable.

It's the capacitance of the cable that causes the roll-off in the first place by effectively being a cap in parallel with the lower part of the volume pot track.

Changing cable type and/or length can drastically change the cap and/or resistor values you need, so there can be no universal answer even for known pickup types and pot values.

Amp voicing can also make a difference too.

FWIW I use a 680pF cap (no resistor) on my humbucker PRSs, with a 20' Horizon Vintage II cable - yes, I know that is not the most transparent cable but it's the one that sounds the best to me when the volume is up full; even an otherwise identical 10' one has a slight shrill top-end that I don't like. So I picked my cap value to fit the cable. With my P90 guitar the right value is 330pF. Both of these give (to my ear) an almost perfectly even tone most of the way down, or perhaps very slightly brighter at low volumes, which I find more useful than the other way round; if it's too much you can always roll off the tone slightly.

If I used a shorter or lower-capacitance cable I would certainly have to use smaller cap values or fit resistors - even with a 10' Horizon, the extra brightness is much more noticeable even if I turn down the treble on the amp a bit to compensate for the cable.