Tube PHONO preamp interference - RFI, EMI, bad grounding?

@atmasphere 

I bought the EAR before the ARC LS16 and it's been tested with other things, Bryston B60 was one of them. 

I mentioned it because it's a solid state integrated. When I plugged the EAR into the Bryston the noise was still being picked up. 

There's an interesting point about the ARC though. When I changed the tubes (it's mk1), uses 4 pieces of 6922, the noise was picked up by the ARC too. It was just very quiet and only when the cage was opened. That set of tubes was used, I think it was either JJ or the stock electro harmonix. I'll try if I can make the ARC to pick up the noise again. Anyways, I think it was only apparent for about a minute and then it disappeared. 

I'll have a different set of tubes for the EAR on Sunday. 

@filipm OK. That's 99 44/100% the EAR is at fault. What happens when it is not running off of the battery?

@filipm 

Hmm - perhaps I am missing something but the statement:

"It still acts as a regular cable though, basically an antenna. " - I am not sure is correct once you connect signal to ground. I believe all the energy on the input should be draining to ground at that point. 

I just ran this same test (turns out I also created shorting plugs this way once way back when) with an admittedly quiet solid state phono preamp, and with an wifi router right next to the cut wire ends. When the signal wire was not connected to ground wire, I was picking up all kinds of noise from the router through the phono stage - move the wire further away from the router, the noise got quieter. 

When I twisted the wires together  - absolute silence - nothing, with the wires resting on the router, not even the usual phono stage ocean noise at max volume on the amp. 

I wonder if your ground connection on your input RCAs (internally) are not connected (in which case, the shorting plugs would definitely act like an antenna). I suspect the EAR connects all grounds to a single point from the PCB to the case. Is that connection still good?

@atmasphere when it's not running off the battery - when it's powered from the PS, it's the same except a 50Hz ground loop that is hard to get rid off when powered from the battery.

@ejb14 I can take detailed pictures of the input RCA and post it in here tomorrow. 

That makes the most sense so far - no matter what I plug into the inputs, it seems they are never grounded. Therefore the shielding isn't working, right? Maybe that's why the noise gets quieter when I touch the cables, even the output cables - I'm grounding it. 

I have tried connecting the chassis of the EAR to many things, I wasn't really succesful so far. 

Thanks, I think we're getting closer.

@filipm  (Perhaps) an easy test; take your DMM and with the Ear turned off, verify connectivity between the input RCA jack shields and the ground lug (not the case  necessarily) or the output RCA jack shields. On my phono stages they are all connected together.