Ungula output volume too low/sounds weird (?)

[pinguinotron]

Hey, folks.

Recently tried and built myself an ungula.

The thing does not sound like a Big Muff and only makes sound if everything is dimed. Even then it doesn't achieve unity.

Here are the specs of the stuff I used and some modifications I made:
-I didnt have 1n5187s so I used a 1n4001
-Got myself a lot of some original NKT 2N1308s. For consistency's sake I went with a couple with a hfE of ~240
-I used KT3102V instead of 2n2904s. The hfE was of ~400. Since they were the ones used in the Russian Big Muff I thought this would sound better than the stock parts.
On both transistors, I checked the CBE layout.
-I am using a 5mm pink led instead of a 3mm red one for status.



Do the 3mm LEDs used for clipping need to light up when the circuit is working? In this case they are not.


Any tips/clues would be appreciated

 

[Erik S]

Looks like you’ve got a 220k in R18 where you should have a 2.2k.

 

[Erik S]

R22 also

 

[pinguinotron]

R22 also

Okay, I will see if that is the case and I'l get back to you.



By the way, are the clipping LEDs supposed to light up?

 

[Erik S]

I didn’t notice any visible light while I was testing mine.

 

[pinguinotron]

I didn’t notice any visible light while I was testing mine.

Changed the resistors to the right ones, still q barely noticeable sound.

Do you know what voltages should be across the germanium and silicon transistors when the battery is engaged?

 

[Erik S]

I don’t know what the voltages should be.

I’d start by triple checking that all your components are of the correct values and installed correctly.

It looks like your LEDs may be installed backwards.

LED polarity

The LED symbol printed onto PedalPCB circuit boards is being updated, please read! Proper installation of LEDs in PedalPCB circuit boards Traditionally the Cathode of a diode is installed into the Square pad of a PCB. Symbol #1 and Symbol #2 conform to this standard. Symbol #3 is...

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I’m also not familiar with that transistor sub for the 2n3904. I took a quick look for a data sheet, but they were all in Russian. I know you said you verified the pinout was correct, but that’s something I’d want to double check too.