Treble bleed on JP6 with piezo

[nerdstradamus]

Hi,

As the title says, is this possible? Do I just ground the tone capacitor and then install the treble bleed mod on the volume pot? I'm not good with electronics, so forgive me if I sound stupid. Thanks.

 

[beej]

Backing up a bit ... a treble bleed is a work-around to retain higher frequencies that are lost due to the loading effect on the pickups, largely due to the capacitance from your cable.

With the piezo version of the JP6, you have an on-board preamp that will negate this effect. So simply by using the active output (mono I believe) and selecting magnetic pickups only on the selector switch, you'll have a buffered output from your magnetic pickups that won't lose treble as you turn down the volume.

If you still want to put something in place for when you use a passive output, you'll can wire up a treble bleed on your volume pot. You'll have to experiment a bit to find resistor/capacitor values that work though- perhaps someone can recommend something.

Another option to consider is "50's wiring", where you change where the tone pot connects to the volume pot. This results in less treble loss when you reduce the volume, though it changes the interaction of the tone pot somewhat. (I prefer this approach, and have it wired up on most of my guitars.)

 

[DrKev]

As beej said, with a passive guitar circuit if high frequency loss is an issue when turning down the volume, adding a resistor/capacitor combo to the volume pot is the way to go.

This is my list of the value recommended by the various pickup manufacturers....

Treble Bleed Mod Round-up | DrKevGuitar.com

Based on my recent circuit simulations I recommened that if you use a 10 ft cable from your guitar to your pedla board or amp, choose the Mojo, DiMarzio, or Suhr values. If you use a 30 ft cable choose one of the versions with 1 nF or 1.2 nf capacitor.

The DiMarzio treble bleed vlaues are working great for me (560pF capacitor and 300kΩ parallel resistor).

Note that doing this mod will also change the taper of the volume pot somewhat. Try it and see if suits you.