[yidimsum]

I bought a pair of 1950's Mullard Black Plate ECC35 (supposedly one of the best 6SL7 tube variants) from a guy on Audiogon who said that he had used them for a year in his Cary 805C monoblocks. I was very surprised when I opened the box that they are a pair of "Pearl Cryo-Valve" tubes. Do cryo tubes really make a difference? From the Tube World website, they mention the cryo procedure in great detail. On the box, it says:

"Deep-chill annealed for 24 hrs. at -320 degrees F. This reduces microphonic effects, lowers the dynamic noise floor & increases the "apparent gain" to greatly relax and improve the dynamic and low level resolving power. The pins have been hot-dip, bright-tinned in 60/40 tin/lead solder for much improved contact quality."

I'm going to pop them into my amps tonight. I'm not sure what to expect, at $375/pair I would never buy them new unless I hit the lotto.

Has anyone had experiences with cryo'ed tubes? Do you think a cryo'ed new production tube attains the performance of a good NOS tube?

 

[ServinginEcuador]

yidimsum,

Yep, IME cryo treating does indeed make a difference in the tube's sound. I wish I could say I did some direct A/B comparisons of a pair of tubes that were cryo treated against some that were not, but never had the chance. I have heard from the current owner of the Siemens tubes that I sold anothe rmember here that they are much better than their current CCa tubes that they have. To be fair mine were an older model that had a slightly different construction, so this could contribute to the differences also. The buyer was esctatic with their purchase, so I was happy also.

While I think that a cryo'd pair of current production tubes will improve their sound I doubt it will bring them up to NOS tube sounds. They are just not as good sounding to begin with. I would say that for saving money it would be a REALLY good idea to go with a cryo treated set of current production tubes. They will sound better.

If you want to know about a really cheap place to cryo treat tubes for about $1 each PM me for the web site. I did a batch of about 30 tubes and it only cost a little over $1.50 or so each including round-trip shipping. It is a risk and some tubes can get thermal shock and get ruined by the cryo process, so caveat emptor.

 

[yidimsum]

Thanks for the info SIE. Are all cryo treatments created equal, i.e. number of hours of immersion in liquid nitrogen? Jena Labs is another place that stands by cryo'ing tubes and wires:

http://www.jenalabs.com/pages/cryo1.html

They even talk about cryo'ing CDs/SACDs/DVDs!

 

[ServinginEcuador]

yidimsum,

No, not all treatments are equal. Some don't lower the items down slow enough, some don't leave them at cryogenic temps long enough, and others just don't know how to treat tubes. A tube has disimilar materials in critical places, ie pins coming out of glass, so lowering the temperature slowly enough to allow for a much closer coeffecient of contraction will greatly reduce the potential damage to tubes. I believe they reco a good 48 hours of cryo treatment to make a difference. That allows for about 12-24 hours to lower the tubes to cryogenic temps, than a godo 24 hours at that temp before bringing them back up to room temp.

As to cryo treating CDs and such, wow, that's a bit overboard. Even for a die hard tweaker like myself that's a bit over the top. No wonder us tweakers have a bad name! Sheesh.

 

[Tuberoller]

I'm still torn over the effectiveness of cryo treatments in audio applications,specifically tubes. I have no doubts about the benefits of Cryo treatments in other applications. I was shown the almost unbelievable improvements in metal tensile strength and micro stability on a Titanium Intake valve from the Engine in my 1965 Malibu Race car. My engine builder succesfully demo'd the breaking of a standard non-cryo'd valve on a trans dyno spinning at 17,000rpms when he slowly filled a metal test sleeve with fluid causing the the valves to exlpode. The treated valve never blew up but bent badly. I was sold and treated every part I could,including the connecting rods,valves,valve springs and all the bolts. again,I'm not sure about audio apps but I'm gonna do a comparison when I get the time.

 

[zoboomofo]

I don't mean to thread crap, but what's the deal with the 'Great Britian' reference? Is that a joke?

 

[Orpheus]

well, i know that cryo treatments are used in many mechanical applications. but i don't think they are done the same way. i truly doubt that freezing something after the finished product has already been manufactured does anything beneficial. cryo is part of the maufacturing process, and i'm sure it has it's place in the forging of the part somewhere, but i doubt afterwards.

anyone know anything about cryo treatments as it is used during the manufacturing of mechanical parts?

 

[drewski]

I bought one pair of the croyed Siemens and Halskes CCa's from SIE. I already had a pair of the non-croyed Siemens and halskes CCa's, and they sounded decent- smooth, warm, and very pleasant. But when I tried the croyed pair, they were incredible. The croyed pair was more dynamic and had a much more forward and lively midrange. It was the combination of warmth and dynamics that you strive for in this hobby. But unfortunately for me, one of the tubes got very noisy after only about 100 hours

, so it was a pretty expensive experience.

I've got a batch of tubes and cables that I've been thinking of having cryoed, but I just can't get myself to send several thousand dollars worth of gear to be deep freezed!

 

[yidimsum]

Quote:

Originally posted by zoboomofo I don't mean to thread crap, but what's the deal with the 'Great Britian' reference? Is that a joke?

Heh, I didn't notice that. Maybe Tube World printed some boxes wrong and just ended up using them.

 

[zoboomofo]

Quote:

Originally posted by yidimsum Heh, I didn't notice that. Maybe Tube World printed some boxes wrong and just ended up using them.

Yeah, you'd think that for $375, a guy could get some spell checkage to go with those tubes. : P I've always wanted to try some cryoed accessories for my dac, but that's way out of my budget.

 

[ServinginEcuador]

Quote:

Originally posted by yidimsum Heh, I didn't notice that. Maybe Tube World printed some boxes wrong and just ended up using them.

Aren't Mullards made in the UK? Could that be what they meant when they said made in Great Britian?

 

[yidimsum]

Yeah, they are made in the UK. It's the spelling of "Great Britain" vs. "Great Britian". I don't think Tube World uses the original boxes, they just use boxes that say Mullard and then stick on the stickers with tube test data.

 

[ServinginEcuador]

Tubes made in UK, boxes made in China. I get it.

 

[Budgie]

I did read an article (somewhere) that suggested not cryo'ing NOS tubes as some may crack during the process from heat/cold stresses. Those NOS tubes are valuable and rare so why waste em?
I would think that if the process is slow and careful, the loss should be minimal, though. But it is something to think about before shipping your valuable old tubes off for treatment.