Cryo Treatment: does it provide improvements in sound or longevity?

Mullard Cryotubes

I'll take those one at a time....

I can provide the fact my Mother worked for Mullard (Blackburn) in the 1960s and 1970s on dedicated valve lines that used cryo treatment to Mil-spec valves - then I worked for Philips Electronics for over 12 years and learnt of the work they did (in conjunction with Amperex) to produce cryo valves for the Dutch Navy and Air force in the 1950s, 10960s and early 1970s

Annoyingly, documentation for what was once regarded as classified information is thin on the ground - but the many reference charts and booklets that outline the use of Red, Green, Black and Yellow paint to Mil-spec and Med-spec valves to denote improved design, rare metals and cryo treatment is evidence you'll have to take (or not take)


Thank You....and you too

@faustuss appreciate the kind words! Correct in stealing my heart. She’s 13 now…kind of wish time could slow down to avoid the future. 

@bolong 

Interesting. I had no idea this was something done on tubes long ago. It is hard not presume they had good reason to go through all that effort and expense without reason. And, more than likely it would be for longevity than audio quality. Doesn't mean it might not improve the sound... as a side benefit. 

"She’s 13 now…kind of wish time could slow down to avoid the future."

@toro3 Yeah, it soldiers on, but you’ll be forever grateful that she passed through this world with you. I’m sure she is too.

"One would have to assume one any verification of process would have to come from a third party inspection or process monitoring. Doubt that is included with the tubes."

@bolong Certificate of Compliance. You can ask for that at the time of sale. The buyers in just about any industry especially electronics are required by the company’s internal controls to request one with every purchase from their vendors.