Life of KT 150 Tubes

@decooney- I have spoken with the engineer at Auris and he specifically said to adjust bias 55-60 mA.I have tried 45 mA no difference to my ears. Never tried KT 120, engineer Said not to. Thanks for your input

@Larryi - Lesson Learnt well, unlike Tube preamp which is self biasing , I agree that swapping popped tubes could have damaged my Other Amp. 

It could be a blown fuse or a resistor, but damn this unit requires an experienced tech to even open it. unlike other tube amps I have seen, this unit is almost concealed. The Auris company in Serbia gave me " fantastic solution" take it to their service center in California, while I live in Canada. Upon calling the service center he said it would be cheaper for him to fly to Canada, as both units crated weigh almost  100Kgs. Canadian distributor spoke to me and asked me to take it to Edmonton 300 Kms away to their dealer. I am going this morning and will keep you all  posted. I once again appreciate all you guys for your input and advise.

How do I post pictures?

@Helmholtzsoul - Blowing the fuse is my first Guess, and next is blowing the resistor. To check the fuse  unit needs to be opened. Did talk to experienced vale tech, locally, he said he wouldn't even open it without schematics.  I  certainly wouldn't mind driving 300 kms to the only Dealer in Canada. I am sure the dealer would not give me the service Tech info, because I did not buy the unit from him. Auris has  responded they wouldn't give the schematics. 

@Decooney - I Turn Amp OFF first and ON last. No power outrage or surge.Naim separates is on the same circuit. Never used them simultaneously .Alway had bias set between  55mu-60mu as recommended  by Auris. I spoke to Tung-sol they said life is between 1000- 2000 hours. Thats is a big variation!!!!!

@Lewm-  As I mentioned,  I know both units have an issue. It could have been a tube popped, that is ruled out even with new tubes there is no Biasing.  

My issue is I don't  have an authorized tech near me . Spoken to couple of Vale Techs locally  they need schematics before they will open the unit, which Auris will not give. Emailed the distributer and they say take it to nearest dealer. There is only one dealer in Canada. He says "find out the culprit who popped the KT150". at least he could have said bring it over we will get it checked. This dealer did not sell the unit , he became the dealer much after I got the unit from distributor .

I am still waiting for the distributor to contact me.

@lLoydc -  "You should buy US-made amps". yes, if you are in North America and more so if you are in the US. I would say  before buying check for local authorized center. It is a personal preference that I like European , but comes with a price in North America.  I had issues with Dynaudio during warranty period. canada does not have Dynaudio  distributer  anymore. US distributer were amazingly good to replace a new set of speakers.

I appreciate all your input and advise. Some of you seem so technically sound probably you wouldn’t hesitate to open. While I was communicating with you all Manufacturer emailed me back that he will help me out , he cc’d the distributor to find a Tech for me. If nothing happens then I would venture into opening it.Wonder why they make such great amps , market it without having tech support. I have had amps that lasted me for decades.With The Russian war it is so hard to find KT150, it’s solely made in Russia. 2000 hours life is fair. That would last me around 3 years with using my Naim separates . I have opened up Audio Valve from Germany few times. Newer had major issue , changed tubes and fixed point to point soldering. Auris is a beast , hard to open.

All of you have provide me great support and advise. Thank you guys.

As you guys seem so knowledgeable . Let me tell you this.

When I turned on my pre and monos , left Chanel was not working , checked the input and out , everything was good. I did get a faint burnt smell on the left unit. Left unit had signal coming in. Right unit was working. I changed  both the KT 150 from left to Right , I couldn’t tell which tube popped, that’s it even the right unit stopped working. Both units had signal coming in. But no sound.  

@jasonbourne52-   “Forget those new design KT150 tubes! Only use 6550/KT88's. These have proven reliability - and a lot more affordable! JJ in Slovakia makes good ones.”

JJ6650 is 1.6 amps where as KT 150 is 2.3 Amps. I am sure it will work as I am down sizing. But wondering the SQ? Some one suggested KT120? 

@boomerbillon - where do you draw the line for 'Driving the amp Hard'.  I am following the instruction as per manual and the engineer to specifically have the mU between 55-60, driving 8 ohms focal Sopra 3 speaker. My volume is never past 25-30% on my pre amp Audio Valve Eclipse. Your advise is appreciated.  I will try 6550 and experience the difference.

@decooney - It’s been 2 weeks since I dropped of the Amps at the Dealer. So far no word yet . Dealer did mention amps will be sent to his Tech and it will take 4 weeks  at the least. Dealer did say he received the schematics from Auris and the case is ‘ out of warranty service’ as I missed by 4 months. Mean time i have already ordered KT 150 from Germany , cost me less than 1/2 the price of canada and USA .KT 150 is made only by Tung Sol and they are Russian . I called supplier in the US , shocked to the hear even though it is in stock they are banned from selling because of sanctions.  KT’s are hard to find.Now I am afraid Custom duty will be very high because of sanctions. Will  find out when I get it.

This is nothing but ‘Gouching”  It is true supply is in very big demand for Russian made Tubes. KT 150 used to be available for $100 CAD now you will not find them for $225- $250 per tube now. Canadian availability is very Low, if it is it is pricy.