Hey I am fairly new to tube amps, I just got a 5150, and I didnt really like the sound i was getting with it, So I changed the tubes, power and pre. I just took new power tubes and stuck them where the old one's were (yep no biasing) And they sometimes glow slightley blueish. But I thought that was ok because the 5150 is biased very cold. Anyway It now sounds like complete ass, and is only usable with an overdrive and a noise suppressor in front. Also pretty freqentley there is a noise almost like blowing wind infront of any notes I play.. It's really annoying. And I have almost No sustain. Would a simple bias fix these problems? Thanks!
That's strange. I didn't re-bias my 6505+ when I changed the tubes and it sounds fine. From what I know you don't need to bias the amp because, like you said, it's biased very cold as is.
I'm a little drunk. I'd like to help, but I don't think I could explain well. Here's a website that has some information. If you don't understand, I'll try to help out tommorow: