Cherrybomb Gain

[irmcdermott]

Ok, I'm confused on this one. So I wired up my Cherrybomb and it's working. The gain pot is pretty much useless until it's 3/4 of the way up. I used a 5kB instead of the 10kB like the project document says and it's still that way. I soldered a 5k1 resistor to the outer lugs of the pot and fired it back up and that made the gain pot not do anything.... turning all the way up and it's still a totally clean signal. Thoughts? Thanks!

[maysink]

I built a CSOD from a guitarpcb.com board with the same results (I also used 5K gain pot). The consensus I gathered was "that's just the way it is" w/ the CSOD circuit. I did find the treble allowed the gain to come out a tad earlier but if you want to get gain be ready to back off the (master) volume!

[irmcdermott]

I'm still confused on why putting the resistor on lug 1 & 3 rendered the pot useless. Oh well, I did however find a 2kB 9mm alpha pot in my stock I didn't realize that I had and put that in there and it is MUCH more responsive, so I would suggest that to anyone who builds this one.

[oldhousescott]

I would expect a reverse-audio taper pot to work better in that position. Maybe a 10kc or 5kc unit.

[maysink]

I'm still confused on why putting the resistor on lug 1 & 3 rendered the pot useless.

Possibly wrong value resistor? Or it was grounding out?

Good to hear on the 2K gain pot. How quickly does it go from boost to snarl now? Mine w/ a 5K takes a good 70% before I get to OD territory from 'boost w/ treble & bass eq.' And the last 5% is pure dirt.

[irmcdermott]

I'm still confused on why putting the resistor on lug 1 & 3 rendered the pot useless.

Possibly wrong value resistor? Or it was grounding out?

Good to hear on the 2K gain pot. How quickly does it go from boost to snarl now? Mine w/ a 5K takes a good 70% before I get to OD territory from 'boost w/ treble & bass eq.' And the last 5% is pure dirt.

I'll have to double check the resistor next time. The gain is a lot more responsive with the 2kB pot. Before I swapped it, it was literally nothing until about 75% and then it was like a switch was flipped and it was pure snarl. Now I get some dirt around 40% that sounds pretty nice for rhythm stuff, and then anywhere after 60-70% is when it transitions into the snarl.

Quick question... when I have the gain crank and let a chord ring out I hear a slight oscillation going on, is that a transistor bias issue? If so, how can I fix it? I've never run across this before. Thanks!

Ian