Audio Aero Capitole - 6021W subminiature tube ??


I would appreciate hearing from someone who can explain the performance of these tubes in the Capitole, including the typical life of the tubes, whether they are susceptible to becomming microphonic or noisy, and how to purchase or change them if necessary. I believe I read these are really small (like the diameter of a pencil) and that they are soldered onto the board. If that is true, is it then necessary to send the player back to the distributor or manufacturer if they need replaced, or are these readily available and set up for user installation? How many years is typical for the tubes to perform in the Capitole before replacement is necessary? Thanks.
mitch2
Having owned (currently still do sort of) a Capitole, I recently sent it to Arizona for new tubes to be installed - a fairly easy process and not too expensive. The company is Sedonix and are the official service center in USA for AA.

Unfortunately my CDP came back via UPS and no longer works - thanks again UPS.

Plan to replace the tubes every 3-5 years. You should be able to have a local service shop do as long as they have very good soldering skills.
If you leave the unit on all the time, like I do with my Prima mk2, those tubes won't last more than 2 years. I just replaced my Prima's myself last month after 17,000 hours and the improvement that new tubes brought was shocking. So I suggest you do it at least that often if left on 24/7.

The manual says do it every 10,000 hours but normally 6021 tubes last much longer. They were designed for circuits subjected to exteme g forces, such as missile guidance systems, and to have likewise extreme reliability. I have read that some can last 100,000 hours. But it seems AA makes them run very hard because my old tubes had obvious signs of space charge degradation (leaves a sooty film on the inside). So 17,000 hours was too much already IMO. It may be worse in the Capitole, not sure.

Also, the Sylvanias are not made the same as the Philips. Perhaps part of my improvement was due to the change in brands. The stock Philips have gray open plates whereas the Sylvanias have boxed black plates. So the are NOT the same construction which means they could well sound different. This has been my general experience with tubes in any case.

Replacing these tubes is easy if you are a patient person and have access to a high-quality soldering iron. Having the right tool is everything so don't attempt this with a Radio Shack special. Let me know if you want detailed directions.

Arthur
Hmmmmm...My Capitole's tubes are more than four years old. No problem yet.

Good Thread.
Oh, there was no problem with mine either - I got used to the gradual sound degradation! It wasn't until I installed new tubes that I realized there was a problem before. Besides, I didn't want to wait until an obvious issue "popped" up. You never know how much damage a shorted tube can make and I don't like waiting to find out! For $20 and 1 hour of my time, I am off to a fresh start - and my Prima sure sounds like it too.

Arthur
how much is it for a pair of 6021 tubes. do the SE upgrade really need cryo tubes. or changing capacitors make major difference. V caps are only $100.

comments please

Thank you in advance