Howdy.
I did a fuzz face project in Eagle, based on the General Guitar Gadget '70 fuzz schematic here:
http://www.generalguitargadgets.com/pdf/ggg_ff5_sc_b70.pdf (http://www.generalguitargadgets.com/pdf/ggg_ff5_sc_b70.pdf)
(I added the optional components on mine)
I had boards fabbed, but I'm having a problem with D2 overheating.
It won't bias properly. For reference, my voltages are:
Q1: C=.99 B=.39 E=.17
Q2: C=.52 B=.89 E=.40
The transistors are a 2N2369 in Q1 and 2N3904 in Q2.
I've attached my layout and schematic. Maybe there's something obvious I'm overlooking, but I've checked all the values and orientations of the components, and replaced C4 and C6, as well as changed D2 to a 1N4001.
I kind of don't want to run my probe with the board overheating.
this is a fairly simple circuit, but I'm stumped, so I appreciate any suggestions
Have you tried removing D2 altogether?
Quote from: madbean on September 21, 2014, 10:08:16 PM
Have you tried removing D2 altogether?
I think I did, but I'll try that again. I first replaced D2 with a 1N914, then the 1N4001.
I'm kind of wondering if it's a grounding problem, but the only ground issue I could think of would be the ground pad, and I've re-flowed everything.
thanks
Need to see the traces/layout so we can check the pcb against the schematic.
Photo of other side of the board too might reveal things as well.
dave
Quote from: davent on September 21, 2014, 10:49:31 PM
Need to see the traces/layout so we can check the pcb against the schematic.
Photo of other side of the board too might reveal things as well.
dave
thanks ...
I don't know if this will help. A lot of the back side is covered by the mid pot.
so I removed D2, and it worked, and biased!
Brian's a genius!
it lacks volume for some reason, so that's my next thing to tackle
thanks for the help!