Power Tubes... Can they cause volume (power) loss as they age?

[tunghaichuan***]

Just another reinforcement of my belief that Tung may be God.

Hardly. I would bet that Ch0jin has forgotten more about electronics than I'll ever know. I've just been doing this a long time and am OCD/pedantic about minute details.

I'm having a hell of a time getting a 12AX7 and 12AY7 that aren't microphonic for my 5E3. I'm actually considering NOS.

FWIW, I suspect a lot of new production 12AY7s are nothing more than weak-testing 12AX7s. NOS might be your best bet. Look for 6072 tubes, they are industrial-labeled 12AY7s. They'll probably outlast new production tubes by a great deal, and will probably sound better as well. If you find 6072 tubes, be prepared for sticker shock.

[Ch0jin]

[QUOTE=tunghaichuan;221122]Hardly. I would bet that Ch0jin has forgotten more about electronics than I'll ever know. I've just been doing this a long time and am OCD/pedantic about minute details.

Aww shucks, thanks for that Tung.

The reality is that vacuum tube technology (aside from CRT's) was off the syllabus by the time I studied electronics. All I've learned has been from the older guys I worked with like 15-20 years ago, and recently, from the intrawebs.

You could say I was raised "Solid State" and converted to "Vacuum Tube" in my late 20's.

Just received my package from thetubestore ! Man, $70 shipping really does make those couriers hustle. From Ontario to Sydney in 5 days. That's got to be the fastest I've ever received anything from that far away

Now I just have to wait out the rest of today at work.... (or perhaps a few more days until I build a bias adapter so I can see how the new tubes bias up. Working in a 1 Ohm resistor inside the chassis looks far too much effort. PCB's huh.)

[Commodore 64***]

FWIW, I suspect a lot of new production 12AY7s are nothing more than weak-testing 12AX7s. NOS might be your best bet. Look for 6072 tubes, they are industrial-labeled 12AY7s. They'll probably outlast new production tubes by a great deal, and will probably sound better as well. If you find 6072 tubes, be prepared for sticker shock.

Just won an ebay auction for 2 12AU7 and 1 12AY7: all untested, but I took a gamble for 15 bucks shipped.

[Commodore 64***]

FWIW, I suspect a lot of new production 12AY7s are nothing more than weak-testing 12AX7s. NOS might be your best bet. Look for 6072 tubes, they are industrial-labeled 12AY7s. They'll probably outlast new production tubes by a great deal, and will probably sound better as well. If you find 6072 tubes, be prepared for sticker shock.

I nabbed a used, untested, GE 6072 on ebay for 11 bucks. And it works! Thanks for the heads up! Sounds great too.