I built a big muff,and I have a problem with it. I made it from this layout: http://i102.photobucket.com/albums/m112/monkeyxx/Big-Muff-Pi-Rams-HeadVERIFIED.gif
It works, sound comes from it, although i thought it would be more distorted, but the problem is that i have this rustling sound, that's very similar to turning a faulty potentiometer all time, while playing, hope you get the picture. I tried it with a battery, and with a power supply, same situation. I tested it with an audio probe, and i got this rustling sound immediately after the first resistor R1. I don't have a spare resistor to try and replace it, could it be that it's a faulty resistor? Seems a bit odd to me :/
I'd say make damn sure the solderjoints are all okay. Resistors do introduce noise (higher values = more noise) but I haven't seen (or heard) one do what you describe yet. I have seen bad solderjoints do this - it's all too easy to goof up on that, even when you've been doing it for years. I think you have a broken solder joint there. Possibly the internal connection on the resistor or the following cap could be broken (takes some abuse). You can quite safely replace it with almost anything - if you have a 10k lying around stick that in. The following cap could also be the culprit, but for now my bet's on solder.
If that fails, follow the debugging sticky.
Thanks! I resolded the whole board and now it works :) tnx again
It worked for a while,and the problem reappeared :/ cold solder joint?
most likely. before you resolder the whole board use your audio probe to isolate the problem, your cold joint will most likely be around there. It almost sounds like your transistors aren't making good contact, I've had pedals make that rustling when a transistor is loose in a socket. If your problem is in the same spot, just replace that resistor if you have another just to rule it out.
Make sure your tip is sharp (file or sand it if necessary) and clean. Heat the board and component leg at the same time and make sure the solder flows well. The dot of solder should be shiny when it cools, not dull, and the component should not move at the board. Maybe Google search for soldering tips.
I just bought a new breadboard because my RS board would do the same kind of thing (one of the issues I had with it). I never though about it, but I must've had some loose or gooey receptacles. I've never had this issue with a solder joint (yet, lol), but it explains my (ex) BB issue. ;D
So i have noise right after the first resistor,and after that,of course,in the whole signal path. Interesting, gain pot doesn't affect noise at all, but the tone pot removes all the noise if i roll it off. This indicates that the problem is somewhere between the gain and tone pot, ie in the distortion section. But why there is noise right after the first resistor at the input? Could it be that noise travels backwards an the input somehow?
no. Replace the resistor, make sure your solder joints are good, and see what happens. Also, check that first transistor solder joint. Also, are you working on perf, vero, or a pcb? Are the copper surfaces clean, shiny, and taking solder well? Are your solder joints shiny like i mentioned above?
Okay, I cant figure out what is the problem! I made a new veroboard and soldered new components,but again the same thing, I get this rustling sound...i have no ideas,give me some advice,thanks
might want to look at your amp...?
You said Vero... :icon_lol:
(sorry, lol) Anyways, take a file or sandpaper and chamfer the copper side of your vero board. I don't use the stuff, but there have been reports in the past of the ends of the vero strips being connected by fine traces at the ends of their boards. I wonder if you might have something similar going on here?
When in bypass,guitar sounds normally so its not the amp...traces are not connected by accident neither
I've gotten that kind of sound from having the board dirty with all of the byproducts of soldering (the flux and that stuff). It usually goes away when I clean it with some alcohol and leave it to dry.
Quote from: vasso123 on January 31, 2012, 10:40:30 AM
So i have noise right after the first resistor,and after that,of course,in the whole signal path. Interesting, gain pot doesn't affect noise at all, but the tone pot removes all the noise if i roll it off. This indicates that the problem is somewhere between the gain and tone pot, ie in the distortion section. But why there is noise right after the first resistor at the input? Could it be that noise travels backwards an the input somehow?
did you re-check/re-solder the offboard wiring? were you able to affect the rustling by shifting wires gently and/or gently pushing components on the vero?
I cleaned the board with some alcohol. Now i have a noise problem,the rustling is gone I think when I cleaned the board. If I ground the collector of the 2nd transistor the noise is completely gone. If i ground input on the board the noise gets even louder, and if I ground the base or collector of the 1st transistor noise alters in some way. Thoughts?
Are you numbering the transistors as per the vero layout you provided? Because in that layout Q2 is the first one the signal goes through, then through the sustain control, then Q1.
If you're referring to the actual order, then as to the way you described it I would suspect the sustain control or something around it.
I numbered transistors in order as they appear in the signal path
Does the noise go away if ground the middle lug of the sustain control? or the base of the second transistor?
If I ground the base of the 2nd transistor noise alters in a way, i hear more high frequency noise
Cmon guys, I know that somebody knows! ;D
Bad joint. Bad pot.
Update: I resoldered all elements around 1st two transistors, I again have this noise, it's like 50hz noise, I don't know. But i figured that turning the gain pot almost removes all the noise. At full gain there is a lot of noise, at middle there is no noise, at zero there is noise but less than on full.
What next?
have you used an audio probe? Start at the input jack tip, and work your way through the circuit. See where the noise starts. That's where your problem is.
Can you post clear, high resolution photos of the top and bottom of the board? That will help us see how the components are laid out and what the soldering looks like.
It was a power supply fault, I use a psu from computer,and I didn't remember to filter the output voltage. After putting a larger cap, the problem was gone,thanks for the help guys :)