My 1st tube amp: transformer buzz audible 15 feet?

This is NOT normal. Return it and get a full refund.

This is not acceptable and is ridiculous for them to tell you anything otherwise.

There are plenty of other integrated tube amps that will NOT give any transformer hum.

Return it NOW. The other thing to check is a loose tube socket. Touch the tubes with a wooden stick and see if one of them is resonating. If so, a socket may be loose. If so, then you return it. Either way, return it. The transformer is just a buzzer, get rid of it. The goal is less noise, not more. If they don't have better quality control, change brands. Jallen

What is your amp sitting on? I had a similar problem with a more or less new RM-10. It was my first tube amp as well and I could hear it 10 feet away. I had it sitting directly on a piece of ply on spikes on a rug over concrete. I believe it was resonating with the ply and amplifying the existing hum--and it was annoying as hell. I happened to have some herbies tenderfoots I wasn't using so on a whim I stuck them underneath the amp. Problem solved. I can still hear the same hum if I stick my ears right up to the amp but it's no longer audible from my seating position or even 2 feet out. Nothing magical about the tenderfoots, because I switched them out (tonight as a matter of fact) with some audio technica footers I have and same result: quiet. Try it ASAP. I suppose trying a different platform might work as well.

If it doesn't work then, as most everyone has said (and obviously correctly), return it.

It sounds like a defective transformer. Is this unit new? Who makes this unit? A mild buzz is not uncommon in a unit that's a few years old.

I have a pair of monoblock amps and one of them had a slight buzz that eminated from a transformer. The buzz was related to a quality control issue with the epoxy inside the transformer in a small batch of transformers they had received right around the time my amps were built. If the transformer didn't develop a buzz within a couple of weeks, I was told it never would. The other amp was perfectly silent, by the way.

Based on my experience, I would ask your shop to return the amp to the manufacturer diagnosis and replacement of the transformer if necessary.

I have had my amps for over a year and both remain silent.