Mudbunny green russian low volume

[mgwhit]

Testing resistor values once they're connected into a circuit is almost never going to produce accurate results, though.  I'd pull them, test them out of circuit (if only to identify the problem) and then replace them with known good parts (i.e. measured beforehand).  I'd also check out Q3 itself while you're in there swapping out parts.  I'd think there's a much grater chance of having a bad transistor than a bad resistor, but who knows.

I'd also consider audio probing the circuit to see where the whooshing sound starts.

[hubb]

I just did the exact same project with the exact same problem.

Can you post the color code of the resistor you have in R24?

I accidentally had a 100k resistor there instead of a 100R resistor.

-C

edit:corrected nomenclature

[midwayfair]

I can't make that emitter bias happen with ANY of the correct values or anything resembling their markings. I even tried swapping resistors around if you happened to have them in the wrong place.

Try just grounding the emitter. If it doesn't get really loud, then it might be a bad transistor.

[mgwhit]

Can you post the color code of the resistor you have in R24?

I accidentally had a 100k resistor there instead of a 100R resistor.

If it's still the same as it was in the original photo, it's brown/black/brown/gold for 100R.

[Dave1992]

I just did the exact same project with the exact same problem.

Can you post the color code of the resistor you have in R24?

I accidentally had a 100k resistor there instead of a 100R resistor.

-C

edit:corrected nomenclature

It's brown/black/brown/gold & my dmm read 100R

[Dave1992]

So I've checked all the 100K resistor (unsolder a lead to test them) and they all are 100K
Also I've notice that Q4 is the one with the higher reading, not Q3 ( my bad). I've said earlier in this post that I have a DC reading in the tone pot, lug 1 and 2 read 4. 10-40V and lug 3 read 1v and just a bit more. I don't know if it's normal or not, might me the reason why the strange hiss/woosh in the tonestack.

You do you guys think?

[midwayfair]

So I've checked all the 100K resistor (unsolder a lead to test them) and they all are 100K
Also I've notice that Q4 is the one with the higher reading, not Q3 ( my bad). I've said earlier in this post that I have a DC reading in the tone pot, lug 1 and 2 read 4. 10-40V and lug 3 read 1v and just a bit more. I don't know if it's normal or not, might me the reason why the strange hiss/woosh in the tonestack.

You do you guys think?

I still don't know how your emitter can be that high with a 390R, but the numbers are more normal for Q4 at least.

Maybe I missed it, but have you audio probed to see where you're actually losing signal?

There should be DC in the tone pot. There's no capacitor between C3 and Tone 1.

[Dave1992]

So I've checked all the 100K resistor (unsolder a lead to test them) and they all are 100K
Also I've notice that Q4 is the one with the higher reading, not Q3 ( my bad). I've said earlier in this post that I have a DC reading in the tone pot, lug 1 and 2 read 4. 10-40V and lug 3 read 1v and just a bit more. I don't know if it's normal or not, might me the reason why the strange hiss/woosh in the tonestack.

You do you guys think?

I still don't know how your emitter can be that high with a 390R, but the numbers are more normal for Q4 at least.

Maybe I missed it, but have you audio probed to see where you're actually losing signal?

There should be DC in the tone pot. There's no capacitor between C3 and Tone 1.

I don't have an audio prob & don't have access to one unfortunately :/
Wich emitter are we talking about at this point since Q4 seem to be more normal? At R23 I have a 2k7 instead of a 2k (couldn't find any at my local shop)

[midwayfair]

I don't have an audio prob & don't have access to one unfortunately :/

Have you read Jacob's instructions in the tech help rules thread for creating an audio probe? It's literally a capacitor and a cable. I just use alligator clips, so I don't even have to destroy a cable.

[Muadzin]

MAKE ONE! They're dead easy to make (I followed the instructions from the BYOC confidence booster kit) and I cannot troubleshoot without it. Making one was one of the best decisions I ever made as it allowed me to halve my pile of non-working pedals.

You don't even need to destroy a cable. Two alligator clips, a capacitor, a female mono jack and some wire like you use inside pedals is all you need.

[Dave1992]

I don't have an audio prob & don't have access to one unfortunately :/

Have you read Jacob's instructions in the tech help rules thread for creating an audio probe? It's literally a capacitor and a cable. I just use alligator clips, so I don't even have to destroy a cable.

No I haven't, can you send me a link for it?
Merry Christmas btw guys

[midwayfair]

I don't have an audio prob & don't have access to one unfortunately :/

Have you read Jacob's instructions in the tech help rules thread for creating an audio probe? It's literally a capacitor and a cable. I just use alligator clips, so I don't even have to destroy a cable.

No I haven't, can you send me a link for it?
Merry Christmas btw guys

It's the tech help rules thread. It's the sticky in the tech help section. It's required reading Actually, this thread should be there, I'll ask to have it moved.

[Dave1992]

I don't have an audio prob & don't have access to one unfortunately :/

Have you read Jacob's instructions in the tech help rules thread for creating an audio probe? It's literally a capacitor and a cable. I just use alligator clips, so I don't even have to destroy a cable.

No I haven't, can you send me a link for it?
Merry Christmas btw guys

It's the tech help rules thread. It's the sticky in the tech help section. It's required reading Actually, this thread should be there, I'll ask to have it moved.

Just found it, I'll build it over the weekend, keep you guys posted.

[Dave1992]

I've build the probe and checked the circuit & the noise seems to be gone. I've checked everywhere with the schematic and couldn't find anything weird.
A big thank you guys, been very helpful!

[dromilious]

hello guys ! I made two pieces of the mudbunny the green russian edition.I used the 5088 transistors.The only difference is that i used 330 ohm resistors in place of the 390 ohm.My sound is more a distortion with a bit fuzz.i compared it with mudbunnies at youtube and i can hear more fuzz at them.My hfe of the trans is about 350.I used my probe and i checked that the first boost stage gives me the same signal as the input.no boost at all.Any ideas ?