[Philistine]

I have Dan's 999ES CDP with tube rectified PSU.
The PSU has a Mullard 5AR4, and the CDP has Bendix 6900's.  I have tried the standard Tung Sol's that Dan installs and also tried a pair of cryoed Tung Sols, these were an improvement on the standard tubes and very close to the Bendix.
Has any tried cryoing a 5AR4 or the Bendix?  I'm thinking of giving it a try out of curiosity 

[Philistine]

Based on what cryoing did for the Tung Sol's (improved as opposed to changing the sound) then it's worth a shot to see what cryoing a 5AR4 will do.  The Bendix tubes are too $$$$ to risk!

Anyone recommend a reliable cryoing outfit?

[HumanMedia]

http://www.cryo-freeze.com/

You will have to sign to indemnify them for any accidental damage, but they are reliable.

[Vtech2000]

Yes, there is often an element of risk with deep cryogenic treatment of electronic components (tubes in particular).  We have cryo'd scores of new, NOS, and old tubes, and we have yet to loose one to the process.  Of course this is likely attributable to the quality of the employed process itself.

We cryo'd Dan's "standard" Tung Sol tubes, and a NOS Mullard 5AR4 rectifier tube.  Compared to listening to each before and after the cryo treatment process, well worth it, well worth the relatively small risk.  Go for it.  The sonic improvements rendered by the deep cryogenic treatment are incredible.  You won't regret it.

[Ken D]

Brad,

I have 999es and tube PS.  I'm in Seattle.

What company did you use cryo the tungsol and Mullard ?

thanks

Ken

[Bill Baker]

 I am still running our Response Audio RAM Signature CD 25 that we released in conjunction with Dan a few years back. (RAM = Response Audio / ModWright) It was a Music Hall CD25 that Dan modified to use his truth tube stage and no Op Amps. It uses the 5687 tubes. We use to supply these cryo treated Tung-Sol tubes. I have a few non-cryo'ed Tung-Sol here as well. Long story short, I keep going back to the Cryo'ed tubes.

 From what I understand, the Mullard 5AR4 is the Cat's Ass in his new power supply. I have the SWLP with external tube rectified power supply and when I get a few Mullards, I will send one or two in for cryo'ing (along with some other pieces).
 Right now I am running a Groove Tube 5AR4 in place of the Sovtek which was a big improvement to my ears.

 One thing I have noticed is that Cryo'ed tubes seem to last longer?

[ted_b]

Not just a Mullard 5AR4, but the rare Metal Base one (Mullard or Philips).  Dan says his tech LOVES this tube for the 9.0 PS or 36.5 (my new pre, arrived this week) but I can't find one under $350.  I bought the Mullard Sylvania for $75 and am using it currently.  Very nice.