Jen Fuzz III totally quiet - maybe is misbiased?

[gigimarga]

Hello,

I've just built Jen Fuzz III using the schematic (http://fuzzcentral.ssguitar.com/schematics/jenfuzzIII.gif) and layout (http://fuzzcentral.ssguitar.com/pcbs/jenfuzz3layout.gif) from Fuzz Central.

I used BC549C instead of BC239C.

When i've tried i have a very "nice" surprise: no sound!!!

After re-checking all, i measured the voltages (using a 9V battery):

Q1: E=6.93     B=6.97     C=9.02
Q2: E=1.62     B=0.00     C=2.32
Q3: E=1.65     B=2.32     C=1.67

As i saw, the circuit seems to be a Fuzz Face derivative (a boosted one), so i must to have 4.5V on the Q3's collector?

Thx a lot!

[Gus]

The way the input buffer is biased is one issue.

It is not a boosted FF it is a buffered FF type with clipping diodes after the FF type section

Q2 readings don't make sense B at 0VDC and E at 1.62VDC ?

maybe you don't want 4.5VDC at the collector or maybe you do try it and find out

Take a look at the 3 tran in schematics that link at the top of the page

[gigimarga]

Thx a lot Gus!

This is the most stupid thing that happened to me...i've built it looking only at the layout at 01-02 in the morning...so i didn't realized that the PCB is TOTALLY WRONG on the Q2's base and emitter...i will try to modify it as soon as possible...

[gigimarga]

So my readings are ok...with the 150k resitor from Q2's emitter to the ground