Volume Pedal: passive or active?

[Rich_S]

I'm putting together a little special-purpose pedalboard mostly of extra stuff I have lying around.  The signal path will most likely be:

• Dyna Comp (on pretty much all the time)
  
• Rat Clone
  
• Soul Food
  
• Volume pedal
  
• Zoom MS-50G (stereo chorus --> stereo delay)
  
  I have a Cry Baby shell in the shop that was destined for a project I never completed.  It has its original 100K pot in it.  I could just wire it up as a passive volume control.  Ordinarily, I would think 100K was too low for a passive volume control, but the Soul Food will be immediately upstream, with its buffer switched on.  So, the 100K pot will be controlling a buffered signal, with the MS-50G's 1 Meg Ohm input impedance downstream.
  
  Do you think this setup will work OK without serious tone suck or treble loss as the volume is rolled down?  Or, would an active circuit be better?  Any recommendations for a DIY buffer and/or booster circuit that would work well with the Cry Baby's 100K pot to make the pedal active?

[Beo]

I'm curious to see if anyone will respond with informed opinions on active vs passive volume pedals, but I'll suggest that wiring up your wah pot as a passive volume pedal in front of your Soul Food would be a quick solder job... so why not try it out?!

[Rich_S]

Oh, there you go, being all practical.   

[ashcat_lt]

It'll be fine at that point in the chain.  It's a bit low for connection to a guitar directly, but that buffer will handle it.

The real issue is that the pot won't turn all the way in either direction.  Even if you shave off the rubber stopper things, the gear just can't traverse the whole rotation of the pot.  Stock, it sits somewhere in the middle and won't go all the way up or down.  You can turn the pot body a bit and get it to hit one extreme, but it will end up even further from the other.  You have to choose if you need it to go all the way up to unity or all the way down to silence.

A more minor issue is that the taper of those pots isn't always best for volume control.  You can replace the pot or add tapering resistors, but it still song turn all the way.

[Rich_S]

I didn't expect to get full travel out of the pot, but by measuring the resistance, it seems to give me the full span from zero of about 126K.   I measured the taper by counting teeth on the rack:



I guess I'll just wire it up and see how it sounds.

Edit:  Well, I did just that, and it works fine.  There's a bit of a delay coming from full off to the beginning of hearing the guitar.  However, there's also a mechanical clunk which offends me when I pull the pedal fully toe-up.  I think I'll put a thin rubber cushion under the heel to eliminate the clunk.  It will also hold the pedal off full zero a bit, reducing the dead spot at the beginning. 

Volume swells are really fun with the Rat out front, and a ton of chorus and delay after.