250K Volume Pot in MXR Dist+ ?

[guillaume_75]

Hi,

I have an reissue MXR Dist+ and as you know, when the volume is maxed, you just have the unity volume (there's no boost...).
I read on this forum that I could replace the 10K pot by a 100K. What if I use a 250K instead (actually, I have many 250K pots from old guitar projects, and no place to buy pots near home...).

Thanks !

[Mark Hammer]

You can, but as the pot value gets bigger it starts to have a negative impact on what comes after it, at the same time as it has a positive impact on the Dist+ itself.  100k is probably an optimal "all-purpose" value, though whatever larger values do to the signal bandwidth may or may not be a problem for you so try it out.  Just note that changing the pot value does not increase signal beyond what is available post-diode.

The problem you are "fixing" is that the 10k resistor leading up to the diodes and 10k volume pot acts as part of a simulated 20k pot that is never allowed to be turned up more than halfway.  Raising the pot value to 100k makes that  a simulated 110k pot that is never allowed to be turned up to more than 91% of the way.  Changing to 250k makes that a 260k pot limited to 96%.  Does that extra 5% make a difference?  Personally, I doubt it.

[guillaume_75]

Thank you for your answer ! But I don't understand the second part of it... Will a higher value pot really make a difference as far as volume is concerned ?
Should I better add another Ge diode ?

[Fret Wire]

The reissue usually has a 47k log volume pot, and a 470k rev. log dist. pot (both usually Omeg). As far as diodes, your unit has two Si 4148's in it. You could change one out for a 3mm LED. That would give you more volume, but slightly less distortion.