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Volume playback and tubes lifespan

Hello,

I am not much technical .  I own a   Vinnie Rossi   Brama  Integrated  Gen.2.

I wonder if listening at  rather high volume , will reduce the tube ´ s lifespan  compared to listening at low volume .

On internet web site : ´´ .... Here in the Brama, the 300Bs don’t need to be biased as hard, since they are only being used for voltage gain (not power output) and are under dramatically less stress than if they were directly driving speakers. And that means they can run while horizontally entombed inside the Brama’s casework. There’s a reason you normally see power tubes such as the 300B out in the wind, and that’s because when driving speakers, they generate a ton of heat and must dissipate it.  ´´

´´ ...the Brama is fronted by two 300B tubes, one for each channel, in the preamplifier section ´´

maxwave
hjdca's avatar
hjdca
240 posts
 

For Power tubes, ie KT88s, the answer is generally - yes...  but, the lifespan of the power tubes also depends on the tube amp design, plate voltage, transformers etc....  They can last a long, long time, even if playing loud.  For example, I had Reissue Gold Lions KT88 in my pair of MC275s monoblocked for 13 years and they still tested fine, and I have a big room and always play loud.  However the 12AT7s that manage the output of the KT88s tested a little low.   In general though, all things being exactly equal, the power tubes will have a shorter life when playing louder rather than quieter. 

PS.  Turning a tube amp on and off a lot also affects tube life...  A big no, no is to turn on a tube amp, then, turn it off, and turn it on again really quickly.  That is bad for the tubes.  You want to have a big time lag between turning on, turning off, & turning on again.   In general, if I am going to listen to my stereo, my habit is to turn it on for most of the day, and turn it off when I leave or retire for the night. 

ghdprentice's avatar
ghdprentice
9,398 posts
 

No problem. You should get 20,000 or more hours from them. They are not being used as power tubes... the amplifier section is a MOSFET stage. So, there is almost no change in output on the 300B tubes, they are being used in the preamp section.  

maxwave's avatar
maxwave OP
1,074 posts
 

@ghdprentice 

Many thanks . I understand a bit.

Differente opinion than the one of  @hjdca  though.

bigshutterbug
395 posts
 

ghdprebtice is correct. The 300B tubes in that integrated are being used as a gain stage for the input signal, and not as output tubes driving the speaker load. They should last many, many years if the circuit is well designed.  The solid state MOSFET output stage does all the work when driving the speakers at any volume.

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