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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 2 responses by helmholtzsoul

helmholtzsoul
111 posts
 

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.

helmholtzsoul
111 posts
 

After reading the manufacture state the valves last between 1-2000 hours, I think you have your answer. You were close to the 1000 NOT the 2000 mark. I find that as another minus, but the manufacture published the specs before you bought it, (I hope).

I find that rather disheartening when someone builds ANY power amp that the valves only last 1-2000 hours and are very $$$expensive$$$ valves.

If no one want’s to help, why are YOU afraid to open up YOUR amp?

I’m sorry it happened BUT it’s time to fix the amps. BE BOLD! It could be 5 dollars worth of parts and charging up the electric screwdriver.

I just open up my new (old) Cary SLP-05. I could care less what any manufacture says about warrantee if they put a fuse on the inside. It is there to be changed and it blew for the amps protection, NOT the house or domicile. The home has breakers/fuses for fire protection. The Amp has SELF protection. It has zip to do with fire safety and everything to do with AMP protection.

5 bucks worth of parts and some new valves. I have my fingers crossed for you.

Post some pics after you open them.. Lets get some trouble shooting going on..

I use a 40 watt light bulb, switch, and pigtails with alligator clips. I hook up to the clips to the cap, flip the switch a few time and on to the next cap I want to discharge.

When I first started discharging caps in the house, 30 years ago, my wife came out with a pistol, she actually thought someone had shot into the house. I quickly went to the light bulb discharge method.

Remember Granny Clampett? The Little Misses is close. LOL

In any case OP I wish you well, I'm in a close second with a newer GG MC275. I think I lost a transformer. I've never had a Mac transformer fail, I think this one did. 700-1000 for a transformer. It a the new transformer too. My 1964 MC275 won't break. That is one tough amp..

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