Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Guitars => Topic started by: LooseChange on March 27, 2009, 08:34:29 am

Title: Preference on Volume Pot Treble thing
Post by: LooseChange on March 27, 2009, 08:34:29 am
I have a guitar with humbuckers and a 500k volume pot.  The treble drops off really bad.

I've read lots of stuff about add a a cap, add a cap and resistor in parallel.

What do you like to do and what values do you like?

Thanks!
Title: Re: Preference on Volume Pot Treble thing
Post by: jjasilli on March 27, 2009, 08:01:06 pm
Just scroll down on this Guitar board, and you should find some extensive posting on this topic in a few recent threads.  It gives everyone hell - you are not alone.  I'm on my way out the door to a jam.  If you don't find anything just repost.
Title: Re: Preference on Volume Pot Treble thing
Post by: G._Hoffman on March 29, 2009, 12:53:50 am
I don't like the way treble bypass caps brighten up the guitar, so I usually skip them.  Besides, the volume control tone change is part of the sound of the guitar - I like it!

When I get asked to do it, I usually just run a 500pF cap, which is smaller than most people use.


Gabriel
Title: Re: Preference on Volume Pot Treble thing
Post by: LooseChange on March 29, 2009, 05:49:22 am
This guitar drove me crazy when I played with the band. It darkens up way too much.
Gabriel, I have been in your camp about adding the cap. But perhaps it's because I've been doing the same 500p.  Bare Knuckle suggested 2500p with a 220k in parallel. I've seen suggestions for 1000p - 2000p as being the norm.

I guess I've gotta open the guitar up and start clipping values in.

Thanks!
Title: Re: Preference on Volume Pot Treble thing
Post by: jjasilli on March 29, 2009, 08:02:44 am
RE treble bleed mods:  I've come to dislike the Duncan mod which is cap and resistor in parallel.  I now like the Kinman mod which is cap & resistor in series.  There's lots of info on the Kinman website. 

To complicate matters, pot value AND taper are also important factors.  A 1M vol pot will brighten humbucker tone.  For "hi-output" PU's over 12K ohms, a 2M vol pot is worth trying.  A linear taper pot will smoothe out vol changes, and not bunch-up the sweep between 8 - 10 on the dial.  Treble & vol will not drop-off so swiftly when you back-down the vol control.  Apparently vintage audio pots had a less pronounced taper than do today's pots.  So a linear pot is worth a try.

Finally, if you have Gibson LP 2X vol style controls, wiring may be a factor - modern wiring with decoupled vol controls vs. vintage wiring where the vol controls load ea other.

Hope that clears-up everything  ::)
Title: Re: Preference on Volume Pot Treble thing
Post by: G._Hoffman on March 29, 2009, 11:34:03 pm
A linear taper pot will smoothe out vol changes, and not bunch-up the sweep between 8 - 10 on the dial.  Treble & vol will not drop-off so swiftly when you back-down the vol control.  Apparently vintage audio pots had a less pronounced taper than do today's pots.  So a linear pot is worth a try.


No, it just moves the bunch-up to between 3-4.  Linear pots stink for volume, though some folks like them for tone controls.

HOWEVER, there are pots which have custom tapers.  If you don't like normal Audio Taper pots, try a Dimarzio pot - they use a custom taper which some people like (I'm too used to CTS pots, myself, and use nothing else - I guess I just like thing very traditional, because I also like vintage output pickups and standard pot values). 


Gabriel