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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

Showing 4 responses by bifwynne

bifwynne OP
2,206 posts
 
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.
bifwynne OP
2,206 posts
 
Gary (Hifigeek) -- is Steveaudio's experience a rare occurrence with the VT100, or is my general recollection re installing and biasing power tubes in the VT100 on point. More to the point, as an ARC authorized tech, would you recomend that only someone who knows his/her way with electronics repairs handle a retube?
bifwynne OP
2,206 posts
 
Gary (Hifigeek) is right on as usual. I own an ARC VS-115 amp which has bias test jacks OUTSIDE the amp. The ARC supplied plastic screw-driver thingy is a very safe tool to use to access the bias pots. I bought the metal screen tube cage, but will NOT pull the top panel that covers the works in order to screw the cage on. I rest the cage on top without screwing it on just to protect the tubes from an accident. It's just too damn dangerous to expose the electronics!

I just re-tubed my Ref 5 and VS-115 using Kevin's tubes. The old tubes from the Ref 5 and VS-115 had over 3000 hours on them. Major, major improvement!!
bifwynne OP
2,206 posts
 
Gary (Hifigeek), quick Q re 6922 tubes. I own an ARC PH-7 phono pre, which uses four (4) 6922 tubes in the audio section. After how many hours of use shoulod those tubes be replaced?? I have heard various views of 6922 tube life in that application ranging from 4K to 10K hours.
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