I'm a bit of a novice when it comes to stuff inside guitar amplifiers... Although I'm competent at biasing and changing tubes in my DSL. 
I'm helping a friend with his 5150. It's a stock Mk1, fixed bias from the 90's and STILL has the original tubes in it.
For a few weeks now it's been making some strange crackling noises, odd vibrating noises and a fairly audible high pitch ringing (kinda like Tinnitus).
We've tried cleaning all the jack sockets and power tube sockets witch electrical cleaner but the problems are still apparent.
When removing the power tubes I noticed they were all brown, almost burnt looking on the very top of each tube. One of them more brown than the others! I also noticed that one of the tubes wobbles left n right at the base of the tube, where the glass meets the plastic connector that plugs into the amp.
I did the tapping with a pencil on the preamp tubes (which are also stock) and I didn't hear anything unsual other than the light tapping coming through the speakers.
I gave the power tubes a tap too and when I tapped the wobbly tube there was an almighty KERPLONK sound!
Would a set of JJ's sort these symptons out? Any advice would be most appreciated.
P.S. How much do the transformers buzz in your amps? I did a comparsion between the 5150 and my Marshall and they both buzz quite mildly yet it isn't audible through the speakers. Presumably this normal? What causes the hiss through high gain amps? My Marshall and my buddy's 5150 hiss quite alot at high gain settings.
I'm helping a friend with his 5150. It's a stock Mk1, fixed bias from the 90's and STILL has the original tubes in it.
For a few weeks now it's been making some strange crackling noises, odd vibrating noises and a fairly audible high pitch ringing (kinda like Tinnitus).
We've tried cleaning all the jack sockets and power tube sockets witch electrical cleaner but the problems are still apparent.
When removing the power tubes I noticed they were all brown, almost burnt looking on the very top of each tube. One of them more brown than the others! I also noticed that one of the tubes wobbles left n right at the base of the tube, where the glass meets the plastic connector that plugs into the amp.
I did the tapping with a pencil on the preamp tubes (which are also stock) and I didn't hear anything unsual other than the light tapping coming through the speakers.
I gave the power tubes a tap too and when I tapped the wobbly tube there was an almighty KERPLONK sound!
Would a set of JJ's sort these symptons out? Any advice would be most appreciated.
P.S. How much do the transformers buzz in your amps? I did a comparsion between the 5150 and my Marshall and they both buzz quite mildly yet it isn't audible through the speakers. Presumably this normal? What causes the hiss through high gain amps? My Marshall and my buddy's 5150 hiss quite alot at high gain settings.
DUDE! Yeah I was like that when I had a look at it. You should've seen the dirt n' grime I cleaned out of the inside of it. This bad boy spent several years in a damp garage too which is never a good idea!
