Noise experts to the rescue!

[jrc4558]

Hi everybody!

This is mainly a question kind of a topic. But it will take a little of history to provide you educated gentleman with relevant information.

I'm using a stratocaster equipped with DiMarzio Virtual Vintage pickups. These are like stacked humbuckers, so no 60 cycle hum there. After guitar there's a true bypas wah, Crain Anderton Compressor, tonepad tubescreamer, RAT (perf), MicroAmp (perf), EA tremolo (runoffgroove), Easy Vibe, Smallclone (tonepad) and a Digitech Digital Delay.
All this plugs into Fender DeVille 212, which I own for almost five years now and never had problems with.

Yesterday at the rehearsal I noticed some faint noise coming from and amp when all the signal chain is connected, but I don't play. This noise is like faint buzzing, very like 60 cycle hum one gets when the fluorescent lights are on in the room. This noise gets louder when I turn the overdrives on, so it is not coming from and amp, but from somewhere in the signal chain, possibly before the pedals. So far I deducved it to two main possible causes:
1) It's possible that I only NOTICED it yesterday, meaning that I always had it; but the possibility of that is very small. The rig was DEAD quiet before.
2) There could be a problem with guitar wiring (again, impossible. All checks OK and the pickups ARE noiseless).
Could it be the patchcords?
Or maybe something else that I simply am unaware of?

Thank you in advance.

[JimRayden]

Maybe you can try to connect the pedals one by one.

Or maybe you got a new cord the day before that was not shielded well. That has happened to me. :\

Connect the guitar straight to the amp to check guitar wiring...

-------------
Jimbo

[stm]

An old EE I knew played the keyboard in a band during the weekends. He told me that there was a particular place where it was very difficult to play because all the illumination had dimmers, which added a lot of EM noise of 50 Hz (this is the mains frequency here).

Check if the problem has to do with that.  The fact that the gain/distortion effects show this effect is only due to the fact that a small interference x1000 times becomes a huge interference.

[Paul Marossy]

Yeah, any dimmers will cause nasty EMI...

I had a dial-up modem refuse to work when my torchiere lamp was on anything but full on. If I used the dimmer at all, it would cause so much EMI that my modem wouldn't connect to the internet. It took me a long time to figure that out, though. This stuff can get into your signal chain, too.

[Johan]

cables pick up noise too...if you are using patchcables of less than great quality, that could be a source for noise....

Johan

[lethargytartare]

My band just found the culprit behind a lot of noise in our room -- a fridge in a back corner.  Some days it wasn't a problem, some days it was really bad.  Unplugged it and now there are NO problems.

And guitars with noiseless pickups can still pickup noise through the controls if the grounding isn't well done.  And there's ground loop issues -- but you seem certain that that's not an issue.

Good luck!

ltt

[Alex C]

I just posted a video of Satch and Vai playing in Steve's "harmony hut," his private home studio (posted in OT Lounge).  While setting up, someone adjusts the dimmer, and Steve's amp starts buzzing/humming.  Steve says "it's gotta be all the way up" or it will hum.  I guess it happens to the best.

Alex

[niftydog]

dodgy patch cables are the number one culprit. Followed by poor sheilding, either in a cable or within a stompbox or guitar.

How are the effects powered? If they run off wall warts, there's a possibility that the filtering is substandard, causing AC ripple to be imparted on the signals.

There's a multitude of different causes, as others have pointed out. Try to eliminate the number of possibilities - test each stompbox in turn, then each cable in turn, use a different guitar etc etc.

[Paul Marossy]

Yep, the compressor in a refrigerator or air conditioner can cause problems, too.   :x

Glad you figured it out.  

[Paul Perry (Frostwave)]

When chasing noise, I find it is useful to have a phono plug, with a 47K resistor shorted across it.
Then I plug that in, instead of the instrument lead.. that way you can tell 100% whether the noise is in the instrument (or its lead) or in the fx chain.

[troubledtom]

When chasing noise, I find it is useful to have a phono plug, with a 47K resistor shorted across it.
Then I plug that in, instead of the instrument lead.. that way you can tell 100% whether the noise is in the instrument (or its lead) or in the fx chain.

clever,down, and dirty! :wink:
    good one paul
             peace,
                   - tom

[Paul Perry (Frostwave)]

I call it my "no signal generator" :wink:

[Paul Marossy]

That's a great tip. I'm putting that one in my "mental rolodex".