MF X10 Tube Buffer - Tube Rush

I'm new to tube gear so apologies if I'm asking a classic newbie question.

I recently purchased a MF X10 V3 Tube Buffer. I've noticed quite a bit of noise being generated from this device that I understand is Tube Rush. It's only noticeable when no music is being played but everything is power up. I spoke with the Canadian distributor and they tell this is quiet normal and is pretty much inherant in tube gear.

My question is how noticeable should this noise be and is there anything that can be done to eliminate or reduce it? It's quite obvious at times. Also, is the noise still there while music is being played or is it somethgin that only occurs when there is no source feeding it?

I have the tube buffer connected between my pre (a NAD 320BE and my AMPs (pair of ATI602's). Speakers are PMC TB2+. CD MF Xray v3.

Your knowledge is appreciated.

I have that same unit, and mine is quiet...really quiet. You may have a bad tube. I also use it between the source and the pre-try that. Could be a grounding issue too. Any lights on that electrical line?
yeah, mine never did that either, might be a bad unit.
Thanks for the responses.

I'm leaning towards a bad tube as well. I've tried several connection options (between pre and amp, soure and pre etc, different cables and power sources) and I get the same results. It's more like static on the right channel whereas the left channel is a more consistant hiss and isn't nearly as noticeable (you have to be right up against the speaker to hear it).

I'll be taking it in for repair on Monday.

Nothing else on this circuit.