Ground loop hum

@kavakat1 said:

Only Jim’s when preamp is set to the turntable.  O other inputs hum. 

I don't think your problem is caused by ground loop. If a ground loop, It should hum even when the preamp is switched to another source input if the TT is connected to the preamp.

Does the hum sound like this. 60HZ hum 

Does the Rogue preamp have a built-in phono preamp? 

What model Technics turntable do you have?

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@jetter said:

The only time I had a hum that sounded like a ground loop from my turntable was when I was using a set of interconnects that were not properly insulated for turntable use.  Morrow literature made it clear to use their phono specific interconnects for turntable use but I thought I would try my non-phono interconnects anyway and hence the hum.  I then installed "regular" insulated interconnects, and the problem vanished

+1 

That would explain why when the Rogue preamp was set to another input there is no hum. Phono ICs are not shielded and are picking up EMI from a near by non shielded power cord or some other EMI producing AC source.

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Plug everything into just 1 outlet that is on 1 circuit, if there is still a hum something may be loose somewhere 

@OP As the RP-7 is a line level preamp - what are you using as a phono stage and how are you grounding that?

So a ground loop hum must be heard no matter which source is playing thru the preamp? Is that correct? I have a  Musical Surroundings Phonominal II+  phono preamp.