Hum when connected to tube amp by means of 4-cable method.

[errya]

Hello all, I hope someone can help me with this problem I am having. As soon as I connect my Helix with the 4 cable method to my ENGL Sovereign 212 amp a hum appears. I can use the clean channel from the amp, because the added noise stays within limits. However, when I switch to high gain the hum gets waaaay too loud. Both my amp and Helix are grounded and my guitar has EMG's installed. I have read about devices that eliminate noise from signals. Would that perhaps solve my problem? Or are there other things I can try?

Thanks a bunch!

Ferdinand

[fukuri]

This isn't a purely helix issue btw every 4CM unit I have used has this to some degree

you need to isolate the line between the helix and the return

A http://lehle.com/EN/Lehle-P-Split-IIwill give you and isolated signal and break the ground loop

[texasdave]

The Ebtech units are pretty affordable and worth keeping in your bag of spares.   In a perfect world, a ground loop issue wouldn't exist if both units are plugged into the same outlet and not connected to anything else.  the 4cm seems to offer more "joy"  and something like the Ebtech is probably worth a shot.   Not to speak against the Lehle unit above, but the Ebtech is about 1/3 the price (and has 2 channels.)  

[sheehanje]

Couple things - when my Helix is hooked up to my amp AND the computer via USB - I get a very loud hum - disconnecting the USB eliminates it - so check for that.

 

Second - check ALL your cables one by one.  I had an issue where one cable sounded fine isolated, but as soon as it was introduced in 4CM I'd get hum - so really change out each cable one by one and see if it solves your issue.

 

Another thing that was mentioned is plug into the same outlet.   I run a  furman ss-b power outlet to my amp, then run a lead from that to my pedal board.  The strip you can get anywhere from $30 - $40 and it eliminated EFI/RMI noises from my setup.  As a bonus it has a 15' lead which is very handy in some venues. 

 

Also - while it won't cause a "hum" - that's usually a 60 or 50hz cycle from a ground loop - keep any cell phones away from your guitar/pedal board/amp.   I remember once in the studio we were having trouble tracking down an odd noise...  turns out I had my cell phone in my pocket and my guitar's active pickups were picking up interference from it.  Comical, but costly because it was 40 minutes of commercial studio time figuring that one out.

 

Check your levels on your effects loop - make sure all sends/returns/outputs are set to instrument instead of line level.  You may have to back off the output level from some of these too - or if your amp has an effects loop adjustment, back that down a bit.

 

If none of these work - if you have a tube amp you may have a microphonic tube that handles the effects loop.  Check your amp manual for that.

 

Don't give up - the helix took me a while to figure out how to play nice with my Mark V - then my Mesa JP-2C.  In the end it was worth it - I get some killer sounds out of it and definitely an upgrade from my Line6 M13.

 

Good luck!

 

[Ghostflasher]

Hi all, just tried the 4CM Method the first time with my Archon AMP and had an ugly humming. So fiddled around a little and ended up using the helix's phones-out instead of the line-out to the amps return. The humming is gone. I guess it's not the right way to do a 4CM but it works for me. cheers Dan 

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[vmoncebaiz]

I think our boy sheehanje just nailed the hum finder guidelines.

 

If you can, try it with another guitar and see if it is still there.  EMGs are not grounded to the bridge/strings for shock hazard.  So they can sometimes be the culprit.