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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?

vishu

Showing 1 response by kykat

kykat
48 posts
 

Hi Vishu. In your original post you mentioned both tubes went bad at the same time but in your last post you mention the left amp going bad and the right amp was still working. After switching tubes from the bad left amp to the working right amp, the right amp then blew.

 

My guess would be that possibly a bad tube blew an internal fuse or resistor in the left amp, rendering it inoperable. After putting the suspect left tubes into the right amp, it caused the same issue - a blown internal fuse or resistor. Thats just my guess. 

 

I just looked for pics of the internals online. The only ones I found of the circuit board do not show any fuses but I'm not 100% sure these pics are the same as your amp. I'm hopeful that even if it is a resistor rather than a fuse, it will be easy for a competent tech to find a cooked resistor. Sounds like you are on the right road since the distributor has been asked to find a tech for you by the manufacturer.

 

These days, I don't buy anything without thinking about what I'm going to do if it breaks. There are so many boutique, one man operations and foreign manufacturers that it is easy to get stuck on an island with a faulty piece of gear.  I hope you have a quick, successful resolution of your issue!

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