Life of KT 150 Tubes

@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!

The Amplitrex is not going to give a KT150 an adequate test. Better than most other older testers but still it doesnt have the juice. 

Very few tube sellers are willing to test these higher voltage tube correctly as it requires a much higher than normal investment. I checked into a custom made rig and when I finally found a competent builder that was willing the price was just too high for a tube which is more of a commodity and can always be found cheaper than what I would have to charge.

Not necessarily. The Amplitrex can supply 500 volts on the line, which as you say is not ideal, but it is the best out there. This would give one a better idea about the general health of the tube than any other tester i am aware of. Are you aware of a tester that can supply 600 volts? Custom made is probably not the answer for the reasons you state.