Power supply or Pedalboard causing bad hum.

[itamar101]

Hey guys, back in search of more techy answers here.
My pedal board has been adding a fair amount of hum (which is a little "phasy" sounding)  and I was hoping someone could offer a solution to the issue.
When I plug my guitars (mostly humbuckers, all properly grounded) all is fine and dandy. There is a little hum but nothing more than you'd typically expect from an amp.
But, when I plug in via my pedalboard a fair (or perhaps unfair) amount of hum is added to the signal, even when all pedals are switched off. Switching the pedals on does not add any significant hum, if any whatsoever.
My current power supply is a Cioks Schizophrenic, so it should be of rather high quality. 6 isolated outputs, one per pedal.
I have one analog pedal (overdrive, true byspass) and five digital pedals (two of which are true bypass).

Now, the first thing I did was check if my cables are the problem. They seem perfectly fine - no rattle, no hiss, perfect condition and quite new.
Next I checked if the buffered pedals were causing the problems. In short, no. The was no difference when I removed them from the chain.
I checked the power supply, I get the same issue with my Harley Benton Power Plant Jr.

Now this is the weird part:
When I plug my guitar directly into the amp, and plug in the Cioks power supply to power the pedals, I get exactly the same hum - even though I am not running through the pedalboard.
I could really use some advice here.

If it makes a difference, everything is plugged into a 4 way extension cable out of one mains intput (only spaces on the extension cable are in use).
I also tried plugging the power supply into a different spot in the room and it didnt seem to making a noticeable difference.

My power supply and pedalboard are also placed very close to my amp and cab. Could the be a problem?
There seems to be additional noise/interference when put my hand very close to the power supply.

Any help would be greatly appreciated,
Thanks.

[Plenum n Heather]

Have you tried using your pedals with batteries to see if the hum returns? If they are fine, then try introducing one pedal at a time using the power supply to see which is causing the hum. It is probably caused by a ground loop, or perhaps the power supply itself is caught in a ground loop if you get the hum immediately upon plugging the mains into it. Do you have another amp you can try also? Or a recording interface with headphones?

I can definitely recommend Ebtech products for hum elimination. When you verify where you are getting the ground loop from, you should get either an HE-2/HE-8 (line level) or HUM-X (mains). I have two HUM-X and one HE-2, and I use them often for hum elimination. They are NOT ground lifters, so they are perfectly safe.

[itamar101]

Have you tried using your pedals with batteries to see if the hum returns? If they are fine, then try introducing one pedal at a time using the power supply to see which is causing the hum. It is probably caused by a ground loop, or perhaps the power supply itself is caught in a ground loop. Do you have another amp you can try also? Or a recording interface with headphones?

I haven't tried with batteries simply because I don't any and only 3 of my pedals even take batteries.
I do have another amp that I can try, although if I remember correctly it still had the same issues. I currently don't have a recording interface as I lent mine to a friend indefinitely...

[gwEm]

P'n'L has explained you the right approach.

Try the pedals with batteries. Then try removing the pedals from your chain one by one.

For the pedals which don't take batteries you can knock up a little battery connector which will power them from batteries via the 9v input.

You can also buy isolation transformers which will go between your board and the amp.

Some pedals are just hummy with an external PSU, even a good one.

[Plenum n Heather]

P'n'L has explained you the right approach.

Try the pedals with batteries. Then try removing the pedals from your chain one by one.

For the pedals which don't take batteries you can knock up a little battery connector which will power them from batteries via the 9v input.

You can also buy isolation transformers which will go between your board and the amp.

Some pedals are just hummy with an external PSU, even a good one.

Yup, my Fishman Aura introduces a very loud ground hum unless I use a separate, regulated power supply for it.