Minimum volume mod help

[C_Hart72]

I put a new circuit in my volume pedal that looks like this: (sorry I don't know how to draw a real schematic!)


I was looking to use the second pot as min volume so the pedal functions as a "cleanup" control for my fuzz face , and it works, to an extent, but the loudest min is still too quiet. I've tried 250k, 500k, and 1M pots in that spot and none seem to be enough, though I think the 1M was the closest. Any advice here? Thanks!

[antonis]

Hi & Welcome..

You realize that as you've wired ORIG. VOL pot, part of it in series with MIN pot forms a voltage divider with whatever resistance comes BEFORE it..!!

So, wire signal on VOL pot lug 3, output on lug 2 (wiper) and MIN pot on lug 1..
(and short MIN pot lus 1 & wiper..)

[C_Hart72]

Thanks for the schematic! I actually remedied the voltage divider problem before I wired it last night now that I think about it - just swapped lug 1 and lug 2 on vol 1 - I'll have to try the rest of your edits tonight

[C_Hart72]

Hm. Tried it out-wired and rewired a few times to no avail. Min volume did nothing in this case-and I tried various pots & resistors. I feel like this should be so simple! Any thoughts?




Sorry it missed a photo the first time around-and the second pic shows min. Vol in my hand as I wired it the second time after try 1 didn't work-still nothing though.

[C_Hart72]

Ok I wired 4 1M resistors in place of a pot to ground and it's getting closer, but still not enough! Wondering how far I will have to go. It's a sensitive fuzz face I'm trying to tame..

[antonis]

Get rid of MIN Volume pot and wire a resistor between Original Vol pot lug 1 and GND..
(the value of which should be set by the percentage of max/min volume, considering infinite next effect input impedance..)

Use the voltage divider formula of X / (250k + X)..
e.g. for a minimum output 50% of maximum one, use 250k resistor
for 10% use a 25k resistor (quite close..)
for 1% use 2k7 resistor, and so on..

[C_Hart72]

Yes-thanks for the reply. That's what I tried at the end of the day. I started with a 1M resistor and min. volume was still too low, so I kept adding 1M resistors in series but it did not make a big difference. Even with 4 x 1M resistors it sounds like a ~50% cut.

[antonis]

Most possible for next effect input impedance is to be around 250k or so..

Try with Original vol pot 100k to see what happens..

[C_Hart72]

It's some kinda funky pot in there - 200* rotation with no resistance on the last part of the track. Maybe the final solution is a block of wood under the heel..

[antonis]

It's some kinda funky pot in there - 200* rotation with no resistance on the last part of the track. Maybe the final solution is a block of wood under the heel..

Maybe the final solution is a block of wood under the heel..

[C_Hart72]

Ok the saga continues here-I guess it's an input impedence thing, which is above my pay grade..

anyway I just tried the modded vol pedal with the fuzz off (why didn't I do that sooner?) and there is almost no change in volume between toe up and toe down, as you'd expect with 4 meg resistance to ground, but with fuzz face on (analogman sunface low gain) the change in volume is drastic from max to min! What's that about?

[antonis]

Could you please draw a draft schematic of all pots/resistors involved..??
(Including FF Volume pot..)

[fowl]

It's some kinda funky pot in there - 200* rotation with no resistance on the last part of the track. Maybe the final solution is a block of wood under the heel..

Search "effective electrical angle"