Fuzz Face Trimpot

[Schappy]

Ive built a Boutique 60s fuzz face from GGG and finally got it to work.

One problem though, Q2's gain is 140 and I can only get it down to 4.8V with a 10k trimpot.

Should I put in a 20k trimpot or just up the 1k resistor preceding the trimpot.

[petemoore]

  4k7 stop resistor + 10k pot.
  or, since 10 barely covers that end...5k6 +10k pot as Q2CResistor, will sweep pretty even across 5k6 - 15k6, and accomodate the bias-tuning of most GE's in FF's. This may be less intrusive to splice in than a pot change.

[zombiwoof]

I've been advised here that you should always have a resistor in line with the trimmer when you install a bias pot.  Besides giving you a greater range of adjustment, it sets a low resistance setting in case the pot fails.  I soldered the resistor lead across the middle and one outside lug of the trimmer, and soldered the remaining resistor lead and the remaining pot pin into the two pads

Al

[Schappy]

I put a 5.6k in line with the 10k trimpot. Works like a charm.

Thanks for the help.