Foxx Tone Machine prob.

[Xlrator]

Been farting around with this one for a day. I get hiss (like it's wanting to do something) but no sound when effect is switched. I probed and I get signal up to the third transistor (5089s). I can hear the signal get fuzz as it goes thru the curcuit, and the octave works when I switch it. Q4 has real faint fuzz on it's base and it's voltages look strange when I measured them.

9.04 supply
Q1 C 4.06 B 1.63 E 1.02
Q2 C 5.47 B 4.06 E 3.44
Q3 C 6.65 B 0.81 E 0.23
Q4 C 9.03 B 0.08 E 0.00

I removed nearly every component and measured individually. I etched JD's layout. All are O.K. I read thru the archives and found JD had fixed problems with the schem. There was one about a .003uF cap to .03uF. The schem has a newer date than that in the archive. ?? The diodes I'm using are 1N34A (RatShacks I think). Are those germaniums?

I'm putting it down so I can get some work done. Anyone have any clues or help on this?

Ben

[JohnM]

JD's site has a voltage chart.  Check it out.  It looks like your Q4 is especially off.  -John

[Xlrator]

Yeah, I did check his chart. But I can't figure out why it's way off. All my components seem to check out OK.

[Travis]

Check for bridges (solder or trace).  The collector of Q4 seems to be directly connected to +9.  I'd check around R23 and C13.

For reference:
http://www.generalguitargadgets.com/v2/diagrams/ftmpl.gif

[Xlrator]

Yeah, I got a good etch and have no solder bridges. Checked it 10x with a lens. Once my iron heats up, I'm going to replace R23 again. Last time I checked it, it was 10K.

*edit*
Still dead  :x

[JonC]

Appears to me that Q4 isn't conducting at all -- I'd check the biasing of the base -- the base of Q4 s/b at about 0.81 V, so I'd check that the 470K from +9V to the base is ok.