Noisy pedals

[aran.e666]

Hey guys,

just finished my pedal board with a decent 2A 9v power supply. when i tested the pedals:
1 pedal on: some buzz when i stop playing
2 or more pedals on: serious buzz that changes frequency depending on what pedals are on. for example if i combine distortion with fuzz i get horrendous high pitch squealing where as if i use a compressor with both, it makes the squealing low frequency.

i feel confident that it is the power supply but after i tried a different one and used a noise filter, i still get buzz.

the buzz mainly occurs when i use my multi effects unit (4 guitar pedals inside an old Marshall ValveState foot controller)

I have checked most connections etc but i don't think it is directly related to the wiring since A. it happens with other pedals in my chain B. it does not matter what combo of pedals are on.

I understand that without pictures, diagrams etc it's hard to find the problem but i am confident it's something i'm missing.

thanks

~Aran

[Ralfg]

So no noise when the pedals are bypassed? If you touch the pedals does the noise go away?

[aran.e666]

yeah, if the pedals are bypassed, there is no noise. i've not touched the enclosures yet so i will try. also, when the pedals are disconnected from the signal chain but on, there is no noise so i doubt the pedals are causing dirty grounds.

[aran.e666]

alright so i did some more testing. i powered all the pedals and turned all the pedals on. i unplugged the jack that runs to my amp and moved the tip of it near the power cables. this caused lots of 60 cycle hum but that is somewhat expected since it's a powersource. also when the amp is unplugged, and i touch the footswitch (so any grounded metal) it causes a very loud hum. i think maybe its just interference but why would it be different frequencies? i think i might use some shielded cable to jumper the input and outputs inside the pedal.

finally, i suspect one of my pedals (Boss SD-1) is buzzing is because i removed the clipping diodes. it did not do this before. the only other thing i did was add two footswitches so maybe there is some interference or poor grounding on that one.

[alanp]

Attach 9V batteries, if you want to test whether it's the PSU. This could get expensive for you, though.

[aran.e666]

my bad, i should've mentioned i already tried with similar results. there any chance it could be a bad ground / connection? although i checked, maybe i should go over it again

[PaulL]

You could try knocking up a reasonably thick cable about a foot long with crocodile clips at each end. methodically plug I each pedal separately to see if you can find the culprit that way. Then methodically add a pedal to the chain one by one and try to see if it only happens with one particular pedal or a certain combination. For any culprits use the lead with clips to connect the guitar /jumper lead earths to other nearby grounds such as other pedal bodies.

Is the mains plug of your power supply have a ground connection? That might cause an earth loop, but don't disconnect the earth if it does, that could be dangerous.

[aran.e666]

thanks, i'l give it a try. no, the adapter does not have a ground/earth pin. also, all the pedals apart from an envelope filter pedal cause the noise. i think the EF blocks out all the low frequency or something. let me try some new cables as now i think about it, I've only used one cable to run from the pedal board to the amp.