Problem: Einstein 50W + pedals = hum (ground loop?)


New member
Hi Everyone,

i have the problem, that my Einstein 50W hums, when I plug in a pedal to the seriell oder parallel effect loop. I tried diffrent cables, pedals, pedals with batteries, it's all the same, it's always humming.

The amp is only 4 months old, and that hum is not so loud, but noticable. And that hum wasn't there, when i got the amp. And I have to say, that the hum disappears, when the effect loop isn't used.

Perhaps you have any idea, what it could be? Or if I should simply use a noise surpressor in the effect loop.

I am grateful for each idea........ :D
Normally i use 2 ollmann power supplies (like cioks power supplies on my pedalboard.)

After you mentioned, that it could be a grounded loop, i tried 2 shorter cables, a single pedal and a single 9V power supply. Works fine!

So you could be right, with the grounded loop. And i'm relieved, that it isn't my Diezel ......

So i will try to find the reason for the grounded loop.

I have 9 effects on my pedalboard, powered by 2 power supplies, so it could take some time, to find the fault.

Maybe someone has any experience with grounded loops, and could give me some tips?

thanx :wink:
Sure, I'm no expert but I can try:

- You shouldn't have pedals in the loop using the same power supply as pedals in front of the amp, this can cause a ground loop.

- Daisy chaining multiple pedals of a single supply can also cause loops. Isolated power supplies like a Pedal Power etc. can help with this. Or batteries of course.

- Keep cables as short as possible.

- Keep audio cables as far away from power cables and MIDI as you can.

- Use good quality shielded cabling.

Hope this helps, good luck!
Yes, i found the error in my setup,

tested everything from cables to power supllies....

but i only had to change the plug socket (hope, thats the correct name). I will buy a better one!

thanx, for you're support!