PB4x4 Power Distro Causing Hum

[ghosty999]

Removed my old Ebay power strip on my live rack rig and replaced it with an ART PB4x4 Power Distribution.

It's working out great but when using the Cab Simulated out on the back of my Pre-Amp (when plugged into the ART) into my soundcard there is a constant low frequency hum. When I plug the Preamp straight into a crappy floor plug multi-plug it's totally silent. There is no hum when playing through the power amp, it's only recording!

Any ideas?

 

[Dave L]

Sounds like a ground issue somewhere. Is your soundcard by any chance on that same floor multi-plug?

Try lifting one end of the shield on the cable going from the Cab Sim out to the soundcard, see if that clears it up. But chasing ground loops over the web is next to impossible.

 

[ghosty999]

Sounds like a ground issue somewhere. Is your soundcard by any chance on that same floor multi-plug?

Try lifting one end of the shield on the cable going from the Cab Sim out to the soundcard, see if that clears it up. But chasing ground loops over the web is next to impossible.

Of course! Similar to when someone has a virus and asks you to fix it verbally!

In short.... the ART is plugged into the same multi-plug extension as the soundcard and causes hum. This hum stops when I plug the Preamp straight into the multi-plug (circumventing the ART)

I think my apartment is a grounding disaster, had the same hum on a record player even when it was grounded. Must be noise in the electrics of the building.

 

[Dave L]

It almost sounds like the ART is causing a chassis ground in the rack, does it do the same thing if the preamp is plugged into the ART but the ART is outside the rack?