
ido1957
9K Gold Member
Turned on my amp this afternoon and got the familiar "tubes are wearing out" crackling. Went away after a minute of warm up but it's off to the shop soon before it really starts to crap out.... 

Whatcha gonna get? I've read about and had my own horror story with JCM900's and improper tube selection and bias straight from Marshall. Make sure whatever you get biases properly.
With all these new tubes on the way, this would be a good place to post some tones.
Just sayin'![]()
Those are good powertubes. 17ma is way cold for your amp. I bet you notice a difference on the good side.Greg - he put in a matched set of Electroharmonix EL34's . He said one of them was running at 17mv so it was really low. The other one was okay but he figured a matched set was the way to go. I'm not a tech and I don't mind paying for him to spend two days bench testing this thing, cleaning, soldering etc etc. I'm contributing to the economy/small business and I know he does a good job.![]()