Author Topic: Cryo Valves? (Read 3142 times)

psy · « **on:** April 04, 2008, 01:12:38 PM »

http://www.watfordvalves.com/products.asp?id=10&man=112

Cryo valves... Are these just a way to part a fool with him money? Or is there some truth in the musical qualites of the process?

Roobubba · « **Reply #1 on:** April 04, 2008, 01:22:05 PM »

In the typical "I've heard this but I don't know anything about it first-hand" way that the internet is wonderful for...

I've heard that there's not much difference, so it's probably a waste of money.

Take that with a large pinch of salt: I don't know from first-hand experience myself, and I can't ever remember the source, so it's unverifiable!

Hope this helps, LOL!

Roo

DeanS · « **Reply #2 on:** April 04, 2008, 02:49:32 PM »

Well, taking metals down to this temperature will effect the properties-ie removing stress within the crystal lattice. If absolute zero was attainable then there would be zero stress within the material

Now whether this makes them more musical and sound better- I myself think the 'jury's out on this one. There is however concerns over the different contraction rates between glass and metals and the seal. This could lead to leaking and subsequent early tube failure.

The best tubes I have ever tried have been NOS Mullards and GE's which had probably never been near a helium or Nitrogen dewar!

ailean · « **Reply #3 on:** April 05, 2008, 05:14:22 PM »

I bought a Cryo valve, more or less for the hell of it. The problem is that unless you buy an untreated one to compare with you don't know (and I didn't). But I liked the idea that the process might improve the materials performance and endurance. It was a philips JAN spec 12ax7 from watford.

One day I'll get another untreated one and see if I can spot the difference. :)

HTH AMPS · « **Reply #4 on:** April 05, 2008, 07:18:51 PM »

does the cryogenic treatment permanently change the structure of the metal though? - when it comes back up to normal temperature, surely there's no difference (like Han Solo in Star Wars, ha ha)

ailean · « **Reply #5 on:** April 05, 2008, 07:36:45 PM »

Yes it is a peramenant change. At extremely low temperarture the crystaline structure changes and re-aligns, which is what allows any stresses in the materials to work themselves out. When the temperature comes back up the structure locks back into place but in the new formation. Kinda like melting but colder is how I understand it :)

I read about the process they use, it takes 12 hours to go down to the lowest temperatue, then it soaks for x hours (where x is a number I can't remember) and then 12 hours to come back up to room temp.

It could be a complete crock, but it sounds cool having cryogenically frozen tubes in your amp :)

pagan7 · « **Reply #6 on:** April 07, 2008, 10:15:42 PM »

I can only speak from the experience of replacing the single standard Marshall tube in the pre amp section of my AVT275 combo with a cryo one from Watford Valves and have to say it does make a difference.
The standard Marshall valve was good but the cryo one is better....more of everything....presence, sparkle, gain and mid grunt. Nicer cleans and dirtier distortions.
So a bit like stepping from a Jaguar into a RollsRoyce...similar...but MORE :idea:

Hell Hound · « **Reply #7 on:** April 09, 2008, 09:51:53 AM »

I have a few cryo valves in my Koch head, I bough those because they were advertised as lower noise than their non treated counterparts. They do what they were advertise for, very low noise (almost no noise even at full blast, and some of my tubes aren't cryo. There was a little noise before with the TAD I had)
I have an Harma 7025 in v1 and a NOS Philips 12AX7WA in v2. v3 is stock phase inverter TAD 12AX7WA and a pair of TAD EL84. I'm going to change the phase inverter by another cryo NOS Philips (balanced) I think and get a pair of Sovtek/EH EL84 :)