Can't get a Tonebender working right

[Derringer]

I made a piggybacked one like this using 2n2222's and it worked. I wanted to try again with some lower gain Q's to see if it sounded better.

I just breadboarded it with 2n3903's and it won't sustain or play high notes at all. If I hit the strings hard I get sound and as long as I keep banging out power chords I get sound, but it chops off notes/chords real quick that are left to sustain. Is this called gating ?

here's the schem I created http://i215.photobucket.com/albums/cc241/guyatron/tbmkiiPBNPN.jpg

Battery = 8.94 V

Q1
E 0.1 mv
B  .609 v
C  8.12v

Q2
E 0.2 mv
B  0.3 mv
C  0.727 v

Q3
E 0.4 mv
B 0.728 v
C 4.5 v

I have a 100k resistor on the Q2 collector and had to reduce the 470r resistor to 220r so that I could bias the collector of Q3

I kept trying to tinker with the Q2 collector resistor to see if I could get the voltage up to around 1.0 volt but all I could do was make a 50K pot smoke.

The only trim pot on the circuit is for Q3's collector. I replaced all of the other trims with resistors.


Thanks for any help.

[Derringer]

Got it.

I tore it all down and rebuilt from scratch but this time I increased the gains slightly on the piggybacked stages. I don't know if the problem before was the lower gain from each stage or something else. But it works now. I'll have to try swapping the old emitter resistors in to see if I get the gating problem again.

Still need to test it out on a big amp but so far, through a 5watt tube amp, it sounds more organic than the one I built using 2n2222's

I'm going to try grafting the tone circuit from the 3-knob bender next.

Here's the working schem if anyone else would like to try.