Upscale Audio -- Tubes and Reliability


Just wanted to get this out there for the benefit of A'gon members who own tube gear. All of my gear is ARC tube equipment.

I've been buying tubes from Kevin Deal - Upscale Audio for quite some time. Most recently, I bought a tube set for my amp. One of the KT-120 tubes didn't bias well. Kevin replaced the tube -- no questions asked!

In another case, the common carrier screwed up the delivery of a tube order. I left a VM for Kevin. He returned the call within 24 hours and made the situation right.

As an fyi, Upscale Audio burns in their tubes for 72 hours before testing and matching. Yes, there have been some glitches here and there, but so far Kevin has always come througth and made good.

Although I still buy some tubes from ARC, on rare occassion a few tubes blew shortly after purchase. Yes . . . ARC was 100% reliable in making good. Problem is ARC charges twice the price Upscale Audio charges.

Although I suppose one could argue that an advantage of buying from ARC is that if a tube goes bad and takes out some passives, ARC will pick up the tab. That may be true, but what good is that guarantee if you have to pack up your equipment and send it back to the factory.

In my case, I am fortunate because an ARC authorized tech lives near my house and makes house calls. True! As I reported before, one time a power tube blew and took out a bias resister. The tech came to my house and replaced the resister in about 45 minutes.

So for me, I guess the bottom line is this: if an UA tube goes bad and takes out some passives, is it worth the price savings to have the tech come out to fix the affected gear. So far, the price savings has justified the risk.

FWIW.
bifwynne
Another vote for Kevin at Upscale, got my Primaluna 1 there, a real no hassle excellent experience.
I bought a matched octet of 6550's for my ARC VT100 Mk II from Kevin a few years ago. I was also very satisfied with the experience, but subsequently Upscale announced they would no longer sell tubes for this particular amp. I am not sure where I will go the next time this amp needs re-tubing. I'm thinking of going with KT120s, but I dread paying $100 each from ARC. Any other VT100 MkII owners care to comment on this thread?
Mabonn, just a guess here, but I think it may be because the VT100 Mk II may not be user friendly when it comes to biasing the tubes. I've read somewhere that the bias pots are very close to some high voltage rails or contacts. If my surmise is correct, it's possible that Kevin may not sell you the KT-120s either for safety reasons. I know that he stocks both types of tubes. Btw, Kevin charges $90 for a pair of KT-120s, less than half the ARC price.

You should call him to see what the story is. Please report back. If Gary (Hifigeek) catches this post, perhaps he can weigh in about whether an electronics tech should install and bias the power tubes in a VT100 Mk II.
The reason ARC doesn't want those tubes in that series of amp is because that tube is mounted horizontally. Output tube sockets can become loose over time. It's less of an issue when the tube is mounted vertically. Because the KT-120 is taller, and heavier then it's 6550 brethren, it is far more prone to sagging in it's socket and losing contact with the socket. Thereby causing it to arc, damaging both the tube and surrounding circuit components.