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Prema luna Prolog 5 replacement power tubes (KT88)

Hi folks. long time no talk. 

The symptom: 
My brother in law owns a Prema Luna Prolog 5 power amp. I suspect that one of his tubes has a vacuum leak. The tube will fill up with a blue flame, then burn off the escaped gas then send a loud pop through the speakers when the escaped gas is burned off. 

The question:
Im looking for a replacement output tube for this piece. I doubt Prema Luna makes their own tubes eventhough the tubes are branded with their logo. I suspect that the tubes are made in China. Does anyone know who manufactures the tubes for Prema Luna, or does anyone have a recommendation on replacement KT88's that sound as good or better than the OEM tubes? Oh and of course he is not looking to go to deep into his pockets. I was considering a set of Gold Lions or Mallards which are in the $200-$250 price point for a set of 4 matched. 

Thanks in advance

-Keith
barnettk
barnettk OP
410 posts
 
Ok yes I did consider that since he is a big fan of the brand. 

Thanks 
hgeifman
2,325 posts
 
FYI:  “When installing fresh power tubes, you have to remember that your old tubes likely required less negative bias to maintain the same idle current as they aged. Before plugging in your fresh set of power tubes, you may want to adjust the bias the so the reading on your meter is lower before plugging in the new tubes!


This is a very important step. If you have the bias setting turned up too high (technically the negative bias is too low, causing your meter to read a higher number), it may let the tubes get away from you once the amp is on. In some amps, this can result in a burnt fuse. or worse yet, a burnt resistor. If your amp uses a cathode or auto-biasing circuit, then you don't have to sweat this step, but if you adjust bias manually it is very important”   

The above is from Kevin’s website   


barnettk OP
410 posts
 
Oh and for you Prima Luna owners I apologize for the miss-spelling of the name :). 
barnettk OP
410 posts
 
@hgeifman 

From what I understand the Prima Luna amps are auto biasing. 

This is what Upscale audio recommends when rolling the tubes in the Prima Luna: 

"In KT88's the most common is the Electro Harmonix which is great, the Mullard re-issue and Gold Lion re-issue which in essence are the same tube and are superb."

So I was pretty much in the ball park as I was considering telling him to go with the Gold Lions.

thanks again.
barnettk OP
410 posts
 
@hgeifman 

Oh Ok I just looked at the link. He has the actual OEM KT88's at $55/per. not bad, and that is in his price range. So there ya go. Thanks this has been very helpful. 
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