Quick question about trim pots

[rankine]

I just breadboarded the Dr.Boogey and it sounds okay (a little thin maybe) but not as much gain as I expected. I can hear that the pedal 'wants' to distort more when I really whack the strings. Could this be because I used 10k trim pots instead of 100k trim pots?
Thanks

[John Lyons]

Most likely yes. You may be able to get away with 50K trim pots but not 10K. 10 times too small there.
What is the voltage on the drain pins of each of the FETs? SHould be at least 4.5volts but youcan go up to 7 if you like.
Lower voltage should get you more gain.

John

[petemoore]

  Make sure your Jfets are source above gate, drain 'up there...not too high, wherever sounds best,
  If the pot is turned to full value, try another Jfet of type or other, or add say...4k7 stop resistor to the 10kpot [ for 4k7 - 10k adjust], or stick another offboard pot on the drain and get it biased, work that into a fixed R or fixed R w/pot adjust on board [just using the pot to find the fixed R value or R range you want adjustable].

[MartyMart]

"Most" Jfets will bias up at 1/2 v between 15k and 30-something k SO .. 50k trimpot
is about right, 10k trim is just not enough in most cases !
100k's often are too large and can have a very sensitive area around the bias point
because they are moving too much in value for a tiny physical movement, so I
have started using 50k's as default now and it seems to work great

MM.