#1
I just bought a used SRRI, and it sounds fantastic, but after about 15 minutes of playing, it starts making a smooth static sound. It's sort of like what you would hear if you had no reception on a radio station. I figure it's the tubes, and I had a few people suggest retubing. This is my first tube amp, so I don't really know much about which tubes to get or which ones to replace, so that's where I need UG's help. I play mostly jazz and blues. Here are the SR's tube specs:

  • Two 6L6 Groove Tube output tubes
  • One 5AR4 rectifier tube
  • Four 12AX7 preamp tubes
  • Two 12AT7 tubes

Any help I get is appreciated. Thanks guys.
Quote by guitar_god22

thats about south africa tho...which isnt poor at all.
Quote by RyanInChains9
yea venezula is just the richest country in the world...
#3
Yeah probably a tube issue. If you like the way it sounds go ahead and get some more of the same kind of power tubes. Then you won't have to have the amp biased. If the problem persists you can replace all the others
#4
I would probably replace the preamp and power tubes if you don't know how old they are. If you replace the power tubes, you should still have it biased. Tubes will vary in quality from the same manufacturer, that's why you get them matched when you order them. You bias your amp to run those specific matched tubes at the optimal values. If you ordered 8 matched power tubes now, you could replace them the next time without biasing because they are matched. Certain amps have a non adjustable bias, like Mesa. However, Mesa tests and sells their own tubes so they know they are in the correct fixed bias range for their amps. A good tech can add a bias pot to an amp though, it's a mod a lot of people get. When you bias the amp, you are running the tubes at the best balance between tone and tube life. It's always a good idea to take a used amp to a tech for a once over anyway.
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