Tonebender MKII- Output level trouble.

[wademalorgan]

Hey all
I recently built a tonebender mkii using the mindbender layout from fuzzcentral- http://fuzzcentral.tripod.com/benderII.html.  I used matched pnp transistors from small bear and switched the mindbender layout accordingly (the mindbender layout is set up for npn trannnies).  The fuzz sounds good, everything works.  The only problem is that the bypass volume is a little higher than the fuzz volume even with the tonebender's volume all the way up.  From what i've heard, the output should be much higher.  It's a fuzz pedal so there should be some sort of boost.  Unfortunately I'm not getting the boost.
Another problem that i am having is that the attack knob (2k) only cleans up the fuzz a small amount.  I like the ballsy saturated fuzz but I would also like a more mellow sound too.  I've read about the guitar volume knob trick but I was wondering if a differnent attack pot value would work as well.

Here's the voltages:
V= -9.55
Q1
C=-4.68
B=-.09
E=0.0

Q2
C=-.044
B=-.09
E=0.0

Q3
C=-5.07
B=-0.45
E=-0.36

I've read that the collector voltages on Q1 should be around -8v and on Q2, about -1v.  The voltage on mine are about half those values.  Maybe this is why the output level of the fuzz is lower than the bypass level.  I don't know. 
Any help or suggestions would be greatly appreciated.  Thanks!

wademalorgan

[wademalorgan]

I just did an audio probe through the circuit.  The output is a whole lot louder after the collector of Q3 but then after the 20k trimpot the signal gets lower.  This has got to be the cause of the volume difference.  I just don't know what to do.  Does there need to be a resistor after the collector for this circuit to work?  Is there are particular orientation for the trimpot to be placed and if misplaced could this be the cause of the volume drop?
Thanks!
wademalorgan

[petemoore]

Here's the voltages:
V= -9.55
Q1
C=-4.68
B=-.09* The base I believe should be .6v 'from the emitter voltage. See ROG TB.
E=0.0

Q2
C=-.044
B=-.09* Check ROG for FF Q1 or TB Q2 voltages, this one also looks close to E.
E=0.0

Q3
C=-5.07
B=-0.45
E=-0.36
  *BOth bases Q1 and Q2 at the same exact voltage could be a coincidence, a continuity check between them is something to consider testing, they should not be connected.
  Geo Technology of the Fuzz Face explains much better than I can here about biasing a FF, which comprises Q's 2 and 3 of a three transistor Tonebender.
  Runoff Groove has articles on FF's and TB's with posted 'target' voltages.
 
 

[wademalorgan]

Hey!
Thanks for the input! I will definately check out that article.
wademalorgan