Muffler Noise Gate - Unintentional Fuzz Issue

Immortone

New member
Has anyone figured out the solution if your Muffler noise gate turns out to be an unintentional fuzz? I've seen some posts about it, but no one really answered what was going on or how to fix it.

Long time lurker, first time poster. 😄
 
Solution
Got this figured out.

A couple things were happening and I'm not sure if all of these were contributing or just one. I originally had a 2SK30 for Q3 due to limited sourcing and incorrect research for a replacement. I found the correct transistor for Q3 - 2N5485 (on pedalpcb). This seemed to improve things slightly, but still not the desired effect.

Additionally, I had ran out of 1uf AE caps when I was populating so I harvested one from a stock of populated learning PCBs from the 70's. Replaced that today with a new one and the circuit works as intended.

Also, both NJM4558D and JRC4580D ICs work as replacements for a straight LM4558.
I guess Occam’s razor. When I was sourcing parts, due to availability, I subbed the LM4558 for NJM4558D and the 2N5485 for 2SK30. If this is the issue can someone break it down for me why it’s not working so I can learn from this mistake?
 
Got this figured out.

A couple things were happening and I'm not sure if all of these were contributing or just one. I originally had a 2SK30 for Q3 due to limited sourcing and incorrect research for a replacement. I found the correct transistor for Q3 - 2N5485 (on pedalpcb). This seemed to improve things slightly, but still not the desired effect.

Additionally, I had ran out of 1uf AE caps when I was populating so I harvested one from a stock of populated learning PCBs from the 70's. Replaced that today with a new one and the circuit works as intended.

Also, both NJM4558D and JRC4580D ICs work as replacements for a straight LM4558.
 
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Solution
For any other users who stumble upon this thread, mine did this. As I understand, it's a problem with one of the transistors that handles signal output being near saturation. I had to audition 2N5485s until I found one that worked. Seems like a common problem, unfortunately. When you buy the board, buy a few 2N5485s. I recommend GuitarPCB, as that is where I got mine. Note that not all of them are going to work in this circuit, but it doesn't mean they are defective.

As an aside... nobody here except maybe Robert is making any money from being on this forum. We're just people, mainly hobbyists, looking to help other hobbyists. We reply to troubleshooting threads as we see them, which might take a while since this isn't our job. Kindness and respect go a long way, especially when we feel frustrated.
 
For any other users who stumble upon this thread, mine did this. As I understand, it's a problem with one of the transistors that handles signal output being near saturation. I had to audition 2N5485s until I found one that worked. Seems like a common problem, unfortunately. When you buy the board, buy a few 2N5485s. I recommend GuitarPCB, as that is where I got mine. Note that not all of them are going to work in this circuit, but it doesn't mean they are defective.

As an aside... nobody here except maybe Robert is making any money from being on this forum. We're just people, mainly hobbyists, looking to help other hobbyists. We reply to troubleshooting threads as we see them, which might take a while since this isn't our job. Kindness and respect go a long way, especially when we feel frustrated.
Oh! That’s interesting that it could be the right one and still not work.

Man, I was just joking. Everyone needs relax.

But yeah, thank you for the info
 
I can be the first to say that sarcasm will not get you very far. I of all people know how frustrating it is when you don't fully understand what's going on when your learning. If you take your frustration out on people here and be a jerk you will likely not receive any advice.. I've gotten out of line before here but I realized I was an @ss in my post.. so I came back and humbled myself....... Believe me.. there are some serious powerhouse and talented guys in this group that will go out of their way to help you.... people arent always staring at the latest help post... but bump it and provide pictures and questions and they will literally stare at your resistors and values as well as look up the schematic and compare..... this group has some great people... come in here with an attitude and you'll either be checked or ignored..
 
Thank you everyone for your input. I didn’t mean to upset anyone. Honestly thought this was a dead and buried thread. Still, not an excuse.

It’s nice to see that even if you think your question is buried that it can be brought attention again so that solutions can be found and shared.

Apologies and won’t happen again. 🙏🏼
 
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