Breadboard Pedal (RAT) 60hz Hum

[trueno07]

Hey All,

Big time lurker, new to posting here.

Been working on a RAT w/ mods on the breadboard and I've got a TON of 60hz hum. Guitar plugged in? hum. Guitar unplugged? Even more hum. Battery? hum. One Spot? hum. I'm playing a epi les paul btw, so i've got humbuckers.

I'm new to new to bread-boarding so I'm really not sure what's an normal amount of hum on a breadboard + what's a normal amount of hum from a high gain pedal. I'm also not sure why it would happen on battery power. I've tried screwing around with my on/off and jack section to try and eliminate variables but I really can't figure it out. I also moved the circuit to a different part of the breadboard just in case.

I'm at the point where it's either normal or it's something in the circuit. With that said, what kind of circuit issues could cause 60 cycle hum? Is it normal to hear the hum on battery?

[PRR]

Welcome.

> Is it normal to hear the hum on battery?

It is normal for an open breadboard in a room full of 60Hz power wiring to hum.

Take your rig a mile into the swamp south of my house, hum will be much lower. (Go in the woods north, you get closer to a monster power line.)

[Guitarist1983]

Did you solve your hum problem?
Are you using pots and/or rotary/toggle switches?   If so are their housings grounded?  Touch each one, does the 60Hz hum change?   For example, a rotary capacitor selector with caps doesn't necessarily have a connection to ground.  You should try running a ground wire to the rotary switches' housing.

[Ben N]

Two words: Faraday. Cage.

[trueno07]

Thanks for the suggestions guys. I was able to reduce some of the hum by re-wiring the board and eliminating a lot of redundant wires but it certainly still hums. It's more in line with what I would expect high-gain to sound like though. I'm not really 100% sure if it's solved but it's better. It doesn't help that my desk is right by my speaker amp AND my houses breaker panel AND that I have mega power lines running through my backyard 

Now I can't figure out why it's oscillating but I may save that for another thread after I do my research. Only seems to do it when all knobs are 100% but i'm not sure if that's OK or not.

[GibsonGM]

Something high gain like a Rat, on breadboard, I'd expect to do some squealing, amplifying noise and the like.   If you turn the level down - does it still squeal?  You said 100%...and amp nearby....that's making a very nice feedback loop   

I'd suspect a lot of your troubles will go away once you have a circuit in an enclosure (as stated, "Faraday cage").  First you'll have to determine that it works right, though.  So I'd move the amp, make sure you don't have a desk lamp or other AC thing too close and so on.    If you have the amp down pretty low, and the Rat works well, only feeding back at 100% level and/or gain - you may be all set!

[trueno07]

Thanks for the help guys! Pretty much everything is next to a lamp now that you mention it. When I would turn tone, volume or gain down would stop squealing.

So, two birds with one stone here: I started sticking my finger in there and swirling everything around and realized that when the IN/OUT cables were separated the squealing stopped so I dug out some shielded wire that I had and used it for my IN/OUT wires and the squealing and a lot of the hum went away!

[bluebunny]

Well done!  You have discovered independently that it's often a good idea to use shielded cable for connections to input and output jacks in a high-gain pedal, particularly when those wires are close to each other.

Someone get this guy a sausage!   

[Ben N]

Here ya go!

But the disclaimer: This is from an article that says that a sausage a day increases the risk of pancreatic cancer. So do with that what you may.)

[bluebunny]

But the disclaimer: This is from an article that says that a sausage a day increases the risk of pancreatic cancer. So do with that what you may.

Just avoid being awesome every single day, and you'll be fine.