Tube question - Mark III 60/100

VJIII said:

I'm retubing my amps, and I have a question someone here might have tech knowledge enough to answer...

I have a '89 Mark III which has the 60/100 option (not simulclass). I use this amp in 60 watt mode 100% of the time, I never switch to 100 watt mode. This only uses two of the four tubes, and the other two just burn away never being used. Since I have expensive out-of-production tubes in there, it's kind of a waste to have great tubes in sockets that are never active.

So, is it possible to only put tubes in the sockets that are active in 60watt mode, leaving the other two sockets empty (and not harm the amp!)? Or could I just place some cheap 'dummy' tubes in the sockets that aren't active?

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JazzRules said:

VJIII said:

I'm retubing my amps, and I have a question someone here might have tech knowledge enough to answer...

I have a '89 Mark III which has the 60/100 option (not simulclass). I use this amp in 60 watt mode 100% of the time, I never switch to 100 watt mode. This only uses two of the four tubes, and the other two just burn away never being used. Since I have expensive out-of-production tubes in there, it's kind of a waste to have great tubes in sockets that are never active.

So, is it possible to only put tubes in the sockets that are active in 60watt mode, leaving the other two sockets empty (and not harm the amp!)? Or could I just place some cheap 'dummy' tubes in the sockets that aren't active?

Click to expand...

I'd leave a crappy old pair (that still glow) in the outermost tube sockets. The inner most are used for Class A operation.

Click to expand...