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

@ejb14 There is a transformer hum in the EAR. I thought that's normal. There's also some hum in the LS16. Nothing too loud but when you get head close to the device in absolute silence it's audible. 

The electrician didn't make it yet. But I got the shorting plugs. It's the same as the shorting plugs I have made. It makes no difference at all. - that's kind of a hint. 

Anyways, today's hifishark found an ARC PH5 stage in Netherlands. I'm thinking of picking it up. It will be interesting to see if it acts the same. I was also always curious how these two compare. If the problem remains, I'll sell one of them and keep looking for the solution or I'll just sell both and get a solid state phono stage.

I think you might be right about the lifted ground. I remember bringing home my first dedicated phono stage. There was some kind of hum too. I don't really know what I did but it disappeared after a while a remained pretty quiet. I also had a Primare R15 phono stage, it wasn't quiet either, there was this white noise at higher volume but neither of them picked the noise like the EAR.

That was the first thing I thought of, the transformer is making noise and the tubes are picking it up. But I would never guess the noise of the transformer is caused by a lifted ground. I'll take the EAR somewhere else again and see if the transformer sounds the same. (I didn't mention it before because it's very quiet and seems normal)

@filipm - my calculations might be incorrect, but the EAR  amplifies a those low frequency signals (the mechanical transformer hum is a pretty low frequency I believe) something like 2500 times depending on how low the frequency. First an equalization of 20db for the bass region of RIAA, then another 48 dB for its phono amplification according to the EARs specs. I wonder if lightly touching the tubes with a pencil eraser (thus absorbing some of that mechanical energy) affects it.

This may be caused by the DC voltage on the AC power that I mentioned earlier - easy to check, and you can filter it with device that goes in serial with the power, like the Van Alstine Humdinger or I think iFi has one too. Good test to take it elsewhere to see if you still hear the mechanical hum. Supposedly toroidal transformers are more susceptible. 

@ejb14 I have recorded the transformer hums.

I level of noise is not audible in the room of course but it's audible when you get closer to the device. The EAR is the loudest, the ALLO linear supply for my streamer and DAC is almost not audible at all. 

I placed my iphone microphone on the chassis when recording each of them.

I'd say it's normal but maybe I'm wrong. 

@filipm I think you have already determined that the ground pin of the IEC connector is tied to chassis. Is there an impedance between the chassis and the ground of the input signal? It may be that a component in the grounding scheme of the phono section has failed. This could cause noise to be injected into the phono section.

Regarding the power transformer noise in the rest of your equipment, some of that might be reduced by using a DC Blocker, provided the transformers in question are toroidal.

Its a common mistake to assume that physical transformer noise is getting amplified when you have problems like this. IME that is extremely rare; IMO you have two different problems.

@ejb14 you have mentioned to check for DC presence on the line. Three days ago I have finally received an IEC19 connector for the ARC REF150 power cord and plugged it into the wall (instead of into a power conditioner that restricts the dynamics).

The power amp started to buzz after about 30 minutes of warm-up. I have also uploaded the buzz on the soundcloud page. (One recording is with the closed chassis, the other one is the opened chassis, moving the mic around). The buzz comes from the transformer, not the speakers, nor the tubes.

I called the ARC dealer in the Czech Republic and they said it could be presence of the DC. When they heard the recording, they said it would actually sound differently. What do you think it might be? Can the presence of DC actually damage components?

I have found a thread about the same thing with a REF150 on this forum, the OP had to replace the power transformer but also reffered to a bad tube on the input stage.

Maybe it has something to do with the EAR preamp problem, because both of these units were working fine when I was buying the power amp and listening both of them together in Berlin. 

(It has started with plugging the amp into the wall, worked fine with the power conditioner - technically. the sound is much better when plugged into the wall of course. From that moment it buzzez even when plugged back into the power conditioner)

My experience with tubes is starting to drive me crazy :)

I’ll have the results about the DC on Monday I hope.

If it’s the presence of DC, can any power plant fix this? Of course PS Audio will claim it can but our ARC dealer says it will restrict the dynamics no matter what power plant I choose.