So I recently bought my first amplifier a Traynor YCV50. Great sounding amp IMHO. I basically have a few questions for you guys regarding this amp. Around the 2nd day of using it lightly at the house I noticed some tube rattle when I would play a low G or F# note on the guitar, but it wasn't too bad. Last night I went and played with a loud drummer and had the amp really cranked, today I've noticed back at home that the tube rattle is a bit worse and more audible(sounds like it might be getting amplified through the speaker? ). This tube rattle I'm hearing is usually one of the preamp tubes right ? Apparently mine has Sovtek preamp tubes in it. I should be able to find the right tube by gently tapping it with a pencil correct ? At the end of the night the drummer wanted to try out my guitar and new amp so I let him. When he was done he reached back and turned the amp off before I could tell him to first put it on standby; the amp made a slight popping noise when he turned it off(didn't sound unusual though, just the generic kind of channel switching type pop). Could this have harmed my amplifier ? I also noticed that when I had the amp on standby today before I played it was making some audible hum through the speaker that kind of cut in and out a bit. It did this for about 10-15 seconds, and also did the same thing when I put it in standby when I was done playing around 30 minutes later. What could be causing this ? I'm a little concerned that my new amp may already be developing some problems. Any and all advice is greatly appreciated. Thanks guys!