Audio Research VSI 60 Input transformer noise

Input transformer?

Do you mean the AC power transformer? (The one in the middle.)

If so, I think its a bit unusual for a modern amp to have a noisy power transformer. I assume by noise you mean a mechanical humming or buzzing.

I would not take that as a good sign. It is also a condition that may get worse with age, though most likely the noise will stay the same. The noise is unlikely to improve with use.

"Hot" is also a term that needs definition. As long as the transformer cover is not so hot that you cannot place your hand on it I wouldn't worry too much.

Exactly. i can understand the hiting because of the driver 6H30, but the noise is a little bit higher compare to the ac transformer of the vsi55.

I have a new vsi60, and it has no such issues.
I'd contact ARC

I just noticed your issue. I have a similar problem with my audio research VS110. The power transformer starts incrementally buzzing after 15 min of use and as it gets hotter. At the beginning there is no noise at all. The noise is purely mechanical from the transformer (no buzz is coming out from the speakers). This buzz is due to magnostriction. Typitically this is observed from the beginning, and this is what puzzle me. I am afraid to leave the amp in operation more than 1/2 hour in case I do a more serious damage. I would hate to replace the transormer as this is the most expensive part of this amp. I was wondering if you have found a resolution to your issue.  I wonder if this is an issue that would require replacing the power transformer or this issue is attributed to a wrong re-connection the electrian performed on the amp.  The chassis was damaged and had to replace it that required to cut and reconnect the power as well as the output transformers.   

Any advise would be greatly appreciated.