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Biasing signal tubes on a tube power amp/Quicksilver M120

Took possession of a new pair of Quicksilver M120 power amps with the KT150 tube upgrade a few weeks ago, am in the process of break in with about 70 hours so far. About 30 hours in I noticed that a 12AU7 tube had started to flare up when that amp was turned on so swapped that tube to the other amp and it followed the tube, I contacted Quicksilver and he told me that this is not a concern but to please switch that tube back to it's origional amp as the amp was biased for that specific tube, now my question is if I wanted to tube roll these 12AU7 or 12AT7 tubes am I out of luck and what happens when it is time to replace them as they wear out, are my tube rolling days over or are they just limited? What say you?
tooblue
audioconnection
1,271 posts
 
Many 12Au7 types have this flash on turn on.
 No concern.
  Just make sure you check the bias when you swap in any new tubes.
Quicksilver Great company you should enjoy for many years.
 
 Best,
JohnnyR
 Audio Connection
Quicksilver dealer
tooblue OP
1,922 posts
 
@audioconnection , I am really liking the amps but still a bit confused as to the biasing of the smaller tubes, the power tubes are no problem biasing but I am not aware of the process to bias the smaller tubes.
yogiboy's avatar
yogiboy
5,653 posts
 
The smaller tubes are not biased. You can replace any tube with any brand that you choose. Just make sure it is the same type of tube!
tooblue OP
1,922 posts
 
@yogiboy , thank you , that is what I thought but did not know for sure.
tubegroover
2,320 posts
 
Enjoy those amps tooblue, if they have the same sonic characteristics, with more power being the difference as the silver 88’s I am happily listening to, you are in for a real long term treat. I have owned many tube amps through the years but the Quicksilvers REALLY hit all the right notes, very special, especially in light of what you get for your money.
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