Sunflower fuzz-very low output

[fuzz]

Just built this last night. Q1 measured 79, Q2 I think is 150 or so? Maybe a bit less. Biased Q2 to -4.5v, and the clean bias trim is all the way down.

I hardly get any fuzz, I have to dime both volume and fuzz, and even then it’s pathetic.

Built to specs, the only thing I did different was use a 1u film cap instead of a 1u electro alu cap.

Any ideas?

 

[jwin615]

Did you test your transietors for leakage?

 

[fuzz]

I did not. I have a breadboard set up to do this but iM still new enough at all of this that I need a visual vs. the schematic. I know it’s a simple set up but alas…

 

[harmaes]

Try the clean pot to max to see if that brings in fuzz. Also reflow your pots, they seem kinda “cold”. Are you trimpots the right values?

 

[fuzz]

I’ll reflow and report back. I believe the trim pots are the right values, unless I managed to mix them up. I can double check that as well.

I did remove the fuzz from a pedal efx loop in was in, and some volume and fuzz returned. But the fuzz is super farty sounding…

 

[harmaes]

Was the clean pot not set to max clean and not to no clean? Did you validate?
Your fuzz shouldn’t sound farty if you biased at 4,5v. Do you have some other PNP germaniums to try?

 

[fuzz]

Honestly I have no idea what’s changed. The bias knob is fully counter clockwise.

Taking the fuzz out of the 29 Pedals EUNA effects loop seemed to wake it up. I swapped the original q1 308B (I think, GT308b?) back in, and it’s great now. I don’t think the other transistor was the issue though cause it sounded fine also. Maybe it wasn’t socketed firmly enough…

 

[Harry Klippton]

Fuzz faces sound like garbage after a buffer.

 

[fuzz]

Indeed. However the loop on the EUNA shuts the buffer off and activates whatever pedal is in it.

 

[harmaes]

Having the external bias fully counter clockwise leads to a gated/splatty fuzz sound if you've biased to 4,5v with the external bias in the middle? The internal clean trimpot can also be set to the wrong side so having maximum "clean" and no fuzz.
But you've seemed to resolved your issue. GT308 are great IMO.

 

[fuzz]

I set the external bias knob to noon, then bias to -4.5-ish volts.
I suspect it was a combination of clean trim, lack of bias and maybe the original Q1 transistor just not being happy with everything lol. The 308 seems to be much more "accepting" of an idiot's approach that I seem to employ prior to sitting down and sorting all of the trim pots/bias out.

 

[fuzz]

Ok, back to square one. The pedal is not exhibiting the same low output, low fuzz. I have swapped a bunch of transistors in both Q1 and Q2 and the same issue persists. When its first in line, its weak and quiet. When I put it behind a buffer w/ a touch of boost, it wakes up, but is noisy because of the buffer.

I have reflowed all solder. Short of installing a new footswitch I am at my limit
One thing I noticed, not sure if this is anything, but on my PCB, both trimmers have 5 through holes, but the trimmers have 3. Some other PCB's I have that have trimmers have only three through holes...

 

[Nostradoomus]

One thing I noticed, not sure if this is anything, but on my PCB, both trimmers have 5 through holes, but the trimmers have 3. Some other PCB's I have that have trimmers have only three through holes...

That's a multi trimmer footprint, if you look at the traces you'll see the bottom pads are connected vertically. So you can use the 2 most common styles of trimpots without issue.

 

[harmaes]

Only thing I can advise is to use an audio probe (output jack to a 100n cap) to find where in the circuit the issue starts.
Connect the output jack of the audio probe to the normal output (cable), connect the input of the pedal and start at the input of the circuit. Follow the schematic and touch the 100n cap on the input. You should have signal now. Go to the next component until there's an issue with the signal.
There might be some shorting going on somewhere for instance.

HTH