6922 Tubes!


Hi everyone, There are many old threads about the 6922, I wanted to know what people are using currently that wont break the bank, ( ie...$150 per tube seems a lot). I need to buy 4 new ones for my phono preamp. Should I just order a set of tubes from the manufacturer (Manley Labs) it seems they like to use Electro Harmonics and they are very affordable, so what does a $100 tube do?? because the originals were pretty nice sounding. I just dont want to overspend on tubes for the unit/system im using them in.  Help.

Matt M
128x128mattmiller
@bdp24 
Hi Eric,
Regarding Cryo treatment, I found the following link for Tyra Labs, which  briefly explains there cryo process and the electrical benefits. 
I thought you may be interested, being they are located in Lake Oswego, Oregon; semi close to your local.

http://www.jenalabs.com/cryogenics/cryo-jena.html
http://jenalabs.com/

Wow, thanks a million Brad. Yeah, Lake Oswego is only about a half hour drive from me. Jena Labs has a dealer in Portland too, Echo Audio. Rather than paying Upscale more for each tube, maybe I can take all my tubes to Jena and have them treated. I think they have a minimum charge for the service, no matter the number of items, assuming they'll all fit in the freezing apparatus. Maybe I'll look into having my brass snare drums and cymbals done too!
Even though there claim to being an affordable process, I'm not sure what there definition means. I say this based on the cost of there cables, etc.
I'm considering cryo treatment for some tubes I have, more for increasing the longevity then SQ since NOS tubes are getting more and more expensive and harder to find. Of course any benefit in SQ would be a plus.  I need to do some further research regarding cryo of tubes.
I remember reading somewhere that due to the difference in the temperature coefficient of materials the process ruined a set of IC's; the shield contracted greater then the conductor and or dielectric. JENA claims that there liquid process obtains temperatures much lower then the gaseous process.
Actually I think the term "expansion/contraction coefficient of materials" should replace the term "temperature coefficient of materials" denoted in my above post
Liquid nitrogen is actually not much colder than nitrogen vapor. I also suspect Jena Labs uses the vapor for most of the Cryo process with a dip into the nitrogen liquid for a brief time at the very end. Otherwise thermal shock would be an issue. Furthermore the temperature difference between vapor and liquid within the dewar is only around 20 degrees F so there may be a bit of an exaggeration regarding the temperature advantage of direct submersion. Of course even lower temperatures could be achieved by pressurizing the dewar. In addition, the ramp down time, dwell and ramp up times are probably more significant than the temperatures in terms of effectiveness. Thermal shock would almost certainly occur if the tube or cable or whatever was immersed in liquid nitrogen right away without the slow ramp down and dwell times in vapor. Another indication that temperature per se is probably overrated is that very good results can be obtained with the home freezer, leaving the tubes or cables or whatever in the freezer for 48 hours. You can even ramp up in the main refrigerator section for 6 hours. I estimate that home freezing at -10 F can get within 80% of the results of real -300 F Cryo. Tell all your friends.