Bearfoot Baby Pink Booster volume mod

[alltrax74]

Hello everyone,
I built this booster yesterday evening for its supposed transparency. And yes, it is definitely a great transparent boost, exactly what I needed...

...but, this boost can't deboost. Pot fully CCW, it's unity volume. Is there a way to modify that so that the pot sweep goes from under unity to full boost ?
I wired it without the switch, so true bypass and booster only
Thanks
Bearfoot Baby Pink Booster

[velouriafx]

Did you try decrease the 150k resistor?

[alltrax74]

So far I didn't try anything
Would that do the trick ? (the one connected to boost 1 I guess)

[alltrax74]

I replaced the resistor with a 250k pot, but that changed nothing.
150k resistor back in place

[Addy Bart]

You should try decreasing the value of the resistor so that when the pot is fully CCW you have a smaller minimum resistance. One quick way to have done it would be to add another 150k resistor in parallel with some alligator leads. That would give you 75k.

It’s a 5 minute job though so just pop a smaller value in there.

[alltrax74]

That's what I did with the pot
I tested it on all its course without any difference on the output volume, with boost pot set fully CCW

[Frank_NH]

What I would try is replacing the 150K resistor next to the output with a A250K volume pot and connect your output to lug 2.  You then adjust it to reduce the output.  Note, however, that like a Klon, when the effect is off, your signal still passes through the JFET to the output, but at near unity gain.  The volume control would then make your signal less than unity gain.  Maybe you could use a DPDT switch to bypass the volume control when you turn it off.

Here's the schematic:

[alltrax74]

Thanks Franck, so we are talking about R9 here which obviously makes sense (the one I replaced with the pot is R10...)

I will try that and let you know
Cheers

[Frank_NH]

Yes, R9, with pot lug 2 to output, lug 1 to ground, and lug 3 to C3.

BTW, another option for a relatively transparent boost (with some tone shaping) is the Boss FA-1.  I built the FA-1 PCB from Aion Electronics and it's pretty nice.  There is a also a vero layout for the FA-1 here:

http://tagboardeffects.blogspot.com/2012/12/boss-fa-1-fet-preamp.html

[alltrax74]

Franck I tried exactly what you suggested and bingo
It's a compromise, if I put the volume pot in the position that allows to loose some output, I also loose output on the boost pot, but that's ok for me because there is a lot of boost with this pedal.

What I finally did is remove the output volume pot and put a set and forget trimmer instead. Perfect
Thanks