Life of KT 150 Tubes


Auris audio Mono Block -Forte 150 uses Two KT150 for power output for each monos, Very strangely a both amps popped the KT 150 same time. I can vouch it had less than 1000 hours in 2 years as I have NAIM NAC 252/NAP 300 in the same room. I tested the tubes and one is 100% dead and the rest have very marginal life. With great difficulty I have ordered four new tubes. Would any of you know why this would have happened, in the sense bath amps not working at the same time? I am trying to get hold of Auris in Serbia. Even a good Valve tech will not open the unit without schematics and Auris wouldn’t provide one. I am in Canada. There are 2 authorized service center in the US. When crated both amp weighs 94 Kgs.Not easy to ship. I tried with a borrowed set of TUBES , there is no Biasing at all,mA reads 0, but there is signal coming in and VU display lights up. 

Lesson learnt well not to buy equipment that is hard to service. I bought this even before there was a dealer in canada. I tried contacting the distributor Motet in Toronto. They are telling me to contact Dealer in Edmonton 300Km away. He never sold me the unit, why would he have any interest if he didn’t make any money on this unit? The unit cost $16,800 USD. Any advise what I should do?

128x128vishu

@vishu 1000hrs is premature.  

Which do you turn ON first, amps or preamp?

Which do you turn OFF first, amps or preamp?

Did you have a power outage/surge recently?

I know this is silly. Did you blow a fuse? Are both MB on the same circuit? Maybe one lost a valve (tube) and that affected the other (a surge). I’ve blown tubes that blew the resistors for that valve. That has happened a few times. The rest of the time it was a blown fuse or one going bad from to many hard starts.. That little piece of thermal wire has a BIG responsibility.

I’ve seen 300Bs with 20,000 hours and were close to 100 years old. They had another 20,000 hours left.

1000 hours and 16K+, I’d hand deliver BOTH to the manufacture’s doorstep in Hades before they got away with that one. Serbia here I come.