TONEBENDER MKII- Not reaching unity gain!

[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 seems to 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.

Here's the voltages:
V= -9.36
Q1
C=-6.13
B=-.09
E=0.0

Q2
C=-.54
B=-.09
E=0.0

Q3
C=-4.95
B=-0.54
E=-0.44

I just can't figure out why I can't reach unity gain.  I did an audio probe through the circuit.  The signal is very loud right after the collector of Q3.  However, the volume drops after the trimpot.


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.

Any suggestions would be greatly appreciated.  Thank you!

wademalorgan

[nightingale]

Hi,
Change that 470 ohm resistor to a 1k5. Then you should have gain way past unity at 2:00 on your volume knob. I must warn you that changing that resistor much past 1k5 or so changes the vibe of the circuit. It affects the  the "control circuit" of Q3.

You will have to mess with that trim pot to find something that sounds good to your ears.

I would socket the 470 ohm resistor. Then plug different values in there until you get the output that you need.

Roger Mayer's mods to the fuzz face circuit [which the mkII contains] was to bump the 470 ohm resistor to 1k.

check this out: http://geofex.com/

read the technology of the fuzz face article. it is gold my friend!

be well,
ry