Getting a Signal Hum when using the Helix LT with my Amps Effects Loop, but not with traditional pedals

[NevenT]

I was hoping someone can explain this odd situation to me.  

I have 3 heads with effects loops: TSL, DSL, and an JCM 800 with a Metropoulos zero loss.  

When I use my traditional pedal set up that powered with a Voodu Lab pedal power, I don't get any hum out of any of these amps.  Delay and a clean boost are in the loop, a Tube screamer, Hush, and Chorus are in the front.

I then plug in a Line 6 Helix LT multi effects using 4 CM, and I get a signal hum with either of these 3 amps.  I tried the ground lift on the Helix, no change,  I tried the effects loop button on the rear of the heads (+4 or -10) no change.  I also tried this with an old Digitech 1101 effects processor and I get the same signal hum.

Why would I get no hum using the pedal set up but get one using the Helix or Digitech and how do I fix that?

Thanks.

[MayPRS]

On 4/5/2023 at 1:44 PM, NevenT said:

I was hoping someone can explain this odd situation to me.  

I have 3 heads with effects loops: TSL, DSL, and an JCM 800 with a Metropoulos zero loss.  

When I use my traditional pedal set up that powered with a Voodu Lab pedal power, I don't get any hum out of any of these amps.  Delay and a clean boost are in the loop, a Tube screamer, Hush, and Chorus are in the front.

I then plug in a Line 6 Helix LT multi effects using 4 CM, and I get a signal hum with either of these 3 amps.  I tried the ground lift on the Helix, no change,  I tried the effects loop button on the rear of the heads (+4 or -10) no change.  I also tried this with an old Digitech 1101 effects processor and I get the same signal hum.

Why would I get no hum using the pedal set up but get one using the Helix or Digitech and how do I fix that?

Thanks.

 

Well if you're getting the hum on both LT and Digitech, then the problem is not the Helix (and for that matter also not the Digitech!).

 

Did you use the same cables to connect pedals and the multi effects units? I also had a problem with one of the cables connected to the FX Loop of the amp.

[rd2rk]

Are the VDL and Helix both plugged into the same wall outlet/power strip?

Is Helix connected to your computer via USB? (unplug USB to see if that's the problem)

Is Helix connected to ANYTHING that the regular pedalboard is not connected to?

Also, as @MayPRSsuggested, check the cables too.