Lead Solder Buzz
- Thread starter jimilee
- Start date
comradehoser
Well-known member
A good clean is never a bad idea, but you could also try just subbing the charge pump if you have any extra laying about.
I'll have to look into that flux, too. I clean my boards, but they stay a bit fluxy-sticky
I'll have to look into that flux, too. I clean my boards, but they stay a bit fluxy-sticky
jimilee
Well-known member
Do you have any rail to rail opamps to try in IC2? Kinda throwing things at the wall here.
That whole gain stage ticks a lot of the boxes of the linked article of things not to do.
¿Maybe jumper IC2 pin 2 to pin 5(grounded) with the tiniest cap you have? Like, single digit pf tiny.
That whole gain stage ticks a lot of the boxes of the linked article of things not to do.
¿Maybe jumper IC2 pin 2 to pin 5(grounded) with the tiniest cap you have? Like, single digit pf tiny.
I think Jimi did that a couple of weeks ago. Also, 2 builds with the same issue.
The resistor and cap values around IC2 are scaled poorly. Add a capacitive load and possibly stray capacitance in the board...
Others have had oscilation issues with this one and modding C7 improved it but didn't work here.
jimilee
Well-known member
2 to 5 just made other sounds but 2 to 1 got rid of all the buzzing.
jimilee
Well-known member
Yep, no more buzzing. Which is stranger, I removed everything individually, including C7, but never everything completely.
jimilee
Well-known member
Yes, with pins 1 and 2 of IC 2 jumpered it works. Would I be correct in saying, that’s just a tone shaping stage?
jimilee
Well-known member
Yes it is. Would that make a difference? I was afraid of the possibility of microphonics in a high gain pedal.
Maybe. I'm not a fan of them in the audio path in general but I don't want to kick that debate back up on this thread. If using themin the audio path, c0g type is preferable by far.
They're(x7r or c0g) are ideal for power/bypass/non audio path.
A lot of times, they're fine. But when they're not....
I've chased weird issues a couple of times that ended up being caused by an mlcc. Both were oscillations, or sounded like it. hence, why I bought 7 pounds of silver micas.
First, I'd test you batch and make sure they are in spec. If you would like, I'll toss a couple silver micas in the mail tomorrow to replace C8. Just shoot me a PM with your deets. I'm not certain they're the answer here, but would be intrigued to find out.
benny_profane
Well-known member
Does the GAIN control work with those pins jumped? If I’m following correctly, you’ve turned the gain control into a unity gain buffer.
jimilee
Well-known member
That makes total sense, I see that now. The pot sounds like it mildly affects the gain. I watched several YouTube videos, it’s hard to tell a difference in the gain rotation.
There is nothing soldered into the ground pad that is supposed to ground the input jack. I assume you have that jack grounded some other way?
I have found the source of a buzz before by grounding out the audio pathway until the buzz disappeared from the output. What I mean is ground pin 3 of IC 1. If the buzz stops then you know the problem is in the input circuitry somewhere. If there is still a buzz then maybe try one end of C5. If the buzz is still going then try IC2 pin 3 etc. Actually that is a point - is the input plugged in to anything? I have buzzes before - especially in high gain pedals, just with nothing plugged in. I have a few pedals with switching jacks that automatically ground the input with nothing plugged in and I quite like that.
I have found the source of a buzz before by grounding out the audio pathway until the buzz disappeared from the output. What I mean is ground pin 3 of IC 1. If the buzz stops then you know the problem is in the input circuitry somewhere. If there is still a buzz then maybe try one end of C5. If the buzz is still going then try IC2 pin 3 etc. Actually that is a point - is the input plugged in to anything? I have buzzes before - especially in high gain pedals, just with nothing plugged in. I have a few pedals with switching jacks that automatically ground the input with nothing plugged in and I quite like that.
If it is working with pins 1& 2 jumpered & you have Continuity on the Matching Circles in the Diagram above, your issue is with one of the components attached to those circles that are causing the Buzz ie C7, C8, D1, D2, R9, R10 ??? that you have bypassed with the jumper.
With the jumper removed & No Power connected, see if the Circle of one colour has Continuity with the other colours???
