Hey guys. Rectifier tube knowledge needed.

[Zippy]

Folks, are the cryogenically treated rectifier tubes bs or does it really make a difference. Do you think the price difference is worth paying?

Thanks all,

Zippy

[sam]

Hi Zippy,

Not sure about cryogenically tubes, but this did peek my interest. Here is an interesting link regarding tubes with this process, responses go both ways.

http://dynacotubeaudio.forumotion.com/t ... ated-tubes

[GeorgeB]

Cyro'ed tubes will be just more prone to fail early. Actually it is a complete no-go. While the pin's metal composition is choosen to have about the same thermal expansion coefficient like the glass envelope, this matching is not 100%. If you expose a tube to more than the intended temperature cycling (as spec'ed / guaranteed by design) micro cracks at the seals are likely to form, causing loss of vacuum inside the tube, tube going bad quickly.
Plus, most people would be hard pressed to even tell the difference between a tube rectifier and its solid-state emulation (silicon diode with series resistor) which is a much bigger difference than before/after cyro'ing. Rectifiers are very remote from the actual signal path, after all.

[Case24]

Rectifier tubes should last for years. Decades in fact. They either work or they don't. I have two amps running 50 year old 5Y3GT rectifiers.

[JagInTheBag]

Great feedback Case24

[KenC]

Rectifier tubes should last for years. Decades in fact. They either work or they don't. I have two amps running 50 year old 5Y3GT rectifiers.

As far as I can tell, my '63 Ampeg B-15 is still on its original rectifier tube.

Ken

[Zippy]

I agree. My post was not worded correctly. I have a '58 Silvertone 1391 and a '66 Deluxe Reverb, both with original recitfier tubes. I was just using that tube as an example concerning all cryo tubes. I think it's a marketing thing.

Zippy