Push me pull me octave fuzz producing mostly static

[jdoughty]

So I'm trying a different octave fuzz for now, and I've got it wired up, but not entirely working. I hear mostly static, but some guitar noise comes through.

Pin readings:
Q1 base 4.8
Q1 Collector 6
Q1 emitter 4.4
Q2E and Q3C 4.5
Q2C and Q3E 4.5
Q2B .5
Q3B 4.5
+ 8.7

Off the bat Q2B seems super low, but every connection seems to be there.

I did an audio probe, and noticed the static begins at Q1's base and is a great deal stronger when I move to Q1's collector. I checked where the positive comes into the circuit, and it's quiet there.

Q2s base seems like a hint at an issue in that area, but I can't tell much else.

Any ideas?

[iainpunk]

does the audio probe give any signal at the swich? and on which pins is or isn't any guitar?
is there any signal at any of the pins of the input cap?
i bet one of those is where its gone wrong

cheers, Iain

[duck_arse]

post photos of your build, please. there's no use asking us to check your work when we can't see your work, you see. and maybe a better resolution layout dia, for those of us w/ weak eyes. please.

[jdoughty]

Ok, I flipped all the jumpers to one side. Problem is just as it was, which is expected.

The guitar signal gets as far as the top pin of the gain pot. It goes through the input cap, and through the base of Q1 out the emitter to get there. I can hear a small amount of static on the base and emitter of Q1, but the Collector is where the static is all I can hear. There's no static on the guitar signal side of the input cap.

[jdoughty]

Apologies for the added complexity from the socketed pots. I'm trying to cut costs of trying new ideas by making the circuits modular.

[iainpunk]

i really like the socketed pots, but could you please put some tape over the back of the pots to isolate them?
maybe (probably) ist that Q1, try socketing it and replacing it with a fresh one. (transistors generally don't like solder heat, socketing them is best practice)

cheers, Iain

[willienillie]

pot(s) got solder in the lug rivets? we don't allow solder wires to the rivets, no matter how enticing they appear - it causes too many problems.

[jdoughty]

Ok, I'll replace Q1 as soon as my tykes go down for a nap and see what happens.

Yeah I made note not to use such a small pot board next time... Lots of questionable decisions on that bit... But everything tested ok thankfully.

[jdoughty]

Good news, the signal makes it to the base of Q2 now!

But there's static there as well... So now I get to fix the other transistors as well lesson learned!

[jdoughty]

Replaced both Q2 and Q3 and the static is back all the way to the Collector of Q1. I'm very perplexed

[jdoughty]

Latest:

[jdoughty]

New voltages:
Q1
C6.1
B4.8
E4.4

Q2
C4.5
B3.3
E3.4

Q3
C4.5
B4.6
E3.45

Positive:8.1

Signal does get through, but mostly static

[antonis]

Q2
B3.3
E3.4

Q3
B4.6
E3.45

Q2 Base should stand about 0.6V above Emitter and Q3 Emitter should stand about 0.6V above Base..

[jdoughty]

Q2
B3.3
E3.4

Q3
B4.6
E3.45

Q2 Base should stand about 0.6V above Emitter and Q3 Emitter should stand about 0.6V above Base..

Q3 C and E got flipped. Correct would be
C3.45
B4.6
E4.5

Sorry about that. Still not the expected values though. Is it because Q2s Emitter connects to Q3s collector?

[jdoughty]

So I'm poking around and noticed the audio signal going into the gain pot increases as I turn up the gain. This seems odd since I figured it would increase signal going out the middle pin, but that one remains silent.

[jdoughty]

Ok, so I tried another board as a pallet cleanser hopefully, however, same problem. The signal is clear leaning the input/going through the gain pot, but after that it goes through a cap and starts mixing with static. Both schematics have the base of the transistor as the next stage after the cap, along with a resistor before hitting the base of the next transistor.

http://effectslayouts.blogspot.com/2015/09/devi-ever-electric-brown.html?m=1

I feel like I must be doing something wrong to hit the same problem twice.

[jdoughty]