Life of KT 150 Tubes

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.  

Quote: "“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.”

That might have been true 4-5 years ago. Not so much any more. Its possible OP got hands on some early gen old stock 150s with the amp from 4+ years ago. Just a hunch. They had gotten it sorted out past few years. Again - buying tubes from a reputable tube dealer/reseller matters. Buy from someone with proper test equipment who actually stress tests, listens for noise, and matches output tubes before sending them out. Now fast-forward there are other sourcing problems of course. Hoping at least 1-2 other new builders step up with even better KT120, KT150, KT170 gen tubes. They could sell the crap out of them if they did it right. .

@vishu I had a Jolida 3502p Amplifier and immediately installed cryo’d by Upscale Audio in L.A. 4x KT150’s and they were fine for 8 months. I sold the Amp only to finance the hand building of 6 Orchard Audio Amplifier modules.

The current owner has had the Amplifier since Aug. of 2021 with no issues.

I had Tubes Cryogenically frozen when I bought them from Upscale only because I read somewhere that they will last longer. Nothing to do with how they sound.

Not much help advising you but that was my experience.

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!