LF Noise on Helix LT when reducing guitar volume

[wildbillmojo]

I am experiencing a low frequency ‘beating’ noise or warble (don’t know how else to describe it) that starts when I turn down the guitar volume. Noise gates do help a little but do not fully alleviate the issue. If I turn the guitar full up the problem disappears totally. Happens on Strats and Les Pauls. Doesn’t make any difference what FX are in the chain; as soon as any thing (including an amp) is put there the issue starts.

I have played with the unit’s input impedance and on settings other than Auto or 1M it’s a lot better, but then the guitar sounds rubbish.

 

I’m a player who likes to ride the volume control so this is a bit annoying, particularly as the Amp sims work so well otherwise with this approach.

 

Anyone heard of this before?

 

 

[DunedinDragon]

Sounds like electrical noise.  Is this always on the same electric wall socket or have you tried it in different places or a different physical house or location?  Of course it also could be related to your output setup, or even your guitar and not your Helix.  Try it through a different output setup and guitar to isolate where it's coming from.

[wildbillmojo]

Yeah thanks. It’s not mains hum or ground loop noise (I know what those sound like). Happens on all my guitars but not if I DI them straight into the interface. You’re right that it could be some kind of impedance mismatch between Helix and Interface. I’ll see what I can fiddle with.

Thanks for your help.