Ok, I'm enjoying my new Valve Senior very much, but I'm noticing it is a noisy amp. I have limited experience with tube amps (this is the first one I've owned) and so I don't really know how much noise is normal. I've noticed the noise varies depending on the room (I assume due to different electricity supply etc) but even in the least noise-inducing locations it's still noisy. The noise I get is essentially of two sorts - scratchiness and mild popping (reminds my of how my parents old record player used to sound, perhaps not surprisingly), and feedback (not due to the guitar, and not screechingly loud).

These effects are audible when there isn't even a lead plugged into the amp. They are not volume dependant, so the noise gets easily drowned out as the volume increases - you can't really hear anything other than buttery tube goodness when the volume goes up, but when I'm not playing the noise is clear and annoying. All the controls of the amp work properly and all the tubes light up and funtion as they should so it doesn't seem like there's anything actually wrong with the amp; it's just noisy.

The amp has 2 12ax7 tubes in the preamp and 4 6v6 tubes in the power stage and it's brand new (though who knows how long it was sitting in the shop, given that they've been discontinued for quite some time). The popping I mentioned is a slight popping sound; overall it's like an old stereo playing vinyl though a bit louder, quite noticeable. I have a friend with a Matchless amp and I played around with it today - no sound at all out of it until you crank the volume, and even then it's only a slight hum so nothing like the noise in my Valve Senior. Admittedly the Matchless is five times the price so you'd expect more, but still.

I know with tube 'technology' that I should expect a degree of noisiness due to interference etc, but how much noise is normal? At what point do I take it back to the shop to get it checked? I didn't notice the noise so much in the shop, probably because there were other amps etc being played in the shop and because I was all caught up in the excitement and lovestruck gazing at my new Wildkat . Thoughts? Suggestions? Input?