Unusual hum quesion

[gjcooper]

So, having an issue with unwanted hum that I've never seen before.  Using the Helix as an FX board in front of a Dr. Z Carmen Ghia.  This amp is very simple.  2 knobs, no effects loop.  Brilliant tone.  Here is the scenario...

 

• If I plug my guitar directly into the amp, no hum.
• If I unplug from the guitar and into any output of the Helix I get terrible hum.
  • This is true even if the Helix is turned off.
  • I tried several cables.  All had the exact same behavior.

Anyone know how to fix this.  The Helix/Camen Ghia combination is unusable the hum is so loud.

[rvroberts]

First step - is your Helix getting its power form the same socket/circuit as your amp?  If not make sure it is.

If hum is gone - success.

There is a ground lift on the Helix (well on the floor board anyhow) try this. - success?

if not, as this sounds like an earth loop, make sure your cables are correct - that the earth is connected all the way through (that includes inside your guitar.

If you have hum after all that,  Either your amp has an earth problem or - extremely unlikely, but possible - your Helix is faulty.  The fact you get it even with the Helix off seems very likely to be an earth problem outside the Helix.

If you can run your Helix into your stereo or some other amplification system - try it. (also be sure to use the same power source as that amp)

That will tell you if the Helix is OK.

You are using a correct power plug on the Helix??

[gjcooper]

Moved the amp to the same power source as the Helix.  Problem solved.  Thanks so much!