Psssshhhtt!!  "Vapor lock released, Captain, cryo-thaw complete. Chas connected to the Torii outputs, but it's high risk, Captain: 12WPC of zero-feedback, fully unregulated, dual-transformer single-ended instability per channel into the upper reaches of the sonic stratospheric pure class A POWER.  OK, we've got Mendelsohn's Violin Concerto in D loaded in the transport, NASA-designed Unity Horn Speakers connected to Chas' toes.  Ready, ready! T-minus 5, apply B+ to EL34s, T-minus 3, engage transport, T-minus 1, ramp grid voltage of 6N2Ps........... shake, bake and quake......... wooogie, mooogie and boogey....... Chas is ALIVE!!!".  Discovered after 10 years to have accidentally fallen into the bottom of a cryogenic research vat and then forgotten at -220F until Uncle Sam came around to perform a tax audit and wouldn't believe he had simply disappeared!

Just goes to show, cryo isn't just for tubes, everyone.  Chas looks great: classic grey on top with flashes of white at the temples, tennis fit and wondering what Steve and Co have been up to these last 10 years!  :o

"Ahhhhhhh.  Yes.  A fine, big hello! to Steve, Lon, Randy of Kaintuck, SelmerDave, HurdyGurdy, and so many others I recognize from days gone by.  Rather wonder if anyone still uses that cryo'd cat5 speaker cable or Cryo'd 6N1P-EV tubes I hawked on the cheap all so long ago.

I just retubed what may be the only Gen1 Torii kit ever built (Steve can correct me, if I'm wrong) with new cryo'd, matched Svetlana EL34s
and the sound is darn impressive.  Scary realism in some areas as the new tubes are still breaking in.  Amp built to allow either a small feedback or zero, but zero preferred even if the response is a bit skewed to the highs.  Only one input tube per channel being fed a smallish CD signal, directly off a DAC chip through a teflon cap, so using a 6N2P instead of 6N1P for higher gain.  Great recordings sound pretty incredible.  Poorer recordings are unlistenable, but a flip of the feedback switch and the bad stuff is tamed, but output is then marginally low.  My old Zen Select was more forgiving with similar detail and better frequency balance and easier to drive, but dynamic realism is better on the Torii on my 94db unity horns.  Some things simply sound  90% "real" which is something I only recall back from the days when I was a vinyl-only audiophile with serious $$ into all that turntable, tonearm, cartridge, tube preamp gear.  Pretty good today for a Sony 685V DVD player taking the signal off the DAC through teflon caps with no added amping. (could definitely do with a nice tube gain stage).  

I remember well building this amp 10 years ago now.  Steve hand-drew me a schematic on a sheet of paper, sent a box of parts and all went well until first attempt on this Ferrari fried an output transformer and tube.  New set of transformers later, courtesy of Steve D., and all was stable on the second try.  The amp has a tiny AC hum, but not noticeable once the music starts.

I found a couple of improvements by A-B testing (with another switch) different SS rectifiers.  Finally settled on one which is used as a TV sweep display super-fast, low distortion rectifier --- triangle decay extended and air around instruments increased.  Another was the addition of  small Hammond chokes (one per channel) just before the input tubes B+ voltage --- background noticeably darker with a more refined sound, but no harm to dynamics.  Also, tried larger chokes in series for the output tubes' B+, but then took those large chokes out --- they hurt dynamics too much.

Hopefully, more to come....  glad to see some old "faces" still here.  Chas  :)

Stone!  You remembered the Cat5 cryo'd thread!  OK!  Wonder if anyone else does? I sold that stuff for $1.00 a foot all over the world. I still use that ridiculous thin stuff to feed my massive horns (each weighing about 200 lbs+).  

Funny thing happened today.  Well, the new cryo'd EL-34s were sounding pretty well broken in after 5 days now.  So, I decided to raid an old cache of input tubes I got from a fella in Germany about 8 years ago.  Four Siemens CCa gold pins, four ITT Lorenz 6922 gold pins, four Valvo Ecc83 gold pins, more... compared them with vintage 1974 6N2P-EV.

So, what's funny?  The CCa tubes were sounding so good, I didn't want to stop listening -- the dynamics were just SO right and imaging was pretty good, but seemed to still wander with frequency change.

So, then stuck in the ITT Lorenz 6922 gold pins and had to fiddle with all four to get two which matched as something magical was happening.  Something I never even thought possible from CD trash (when I switched to CD from vinyl, I felt it was like resigning myself to a life of Schlitz after Guiness Stout).

Well, got two low output 6922s in this gold pin Lorenz batch to make some magic.  Not only did my huge unity horns disappear as in "nothing coming from them!", but symphonic instrument placement was accurate front to back AND side to side, with precise "there" placement and no wandering of Isaac Stern playing the Mendelsohn (recorded in '59, now on SACD, tape hiss and all~yeah!).

Solo lute was so rich, focused and just natural -- very meaty sound, dynamics delicately accurate, startlingly powerful.  Reach out and shake my hand imaging!

But it's the imaging.  I never thought any CD could do accurate front to back with proper timbres, and live air.  

Well, I'm gobstoppered!

Hail the Lorenz 6922 in this dear old, modded to the gills Torii Kit.  The most marvellously unstable amp in the universe!

Thanks for the kudos, Stone!

On an absolute basis, I've had systems in the past which performed even greater magic -- and this back in the mid-1980s, when I owned Audio Classics -- a tiny concern dedicated to best sound.

Michell Gyrodec turntable, Souther tonearm, ClearAudio cartridge, Audible Illusions tube preamp, Quicksilver tube monoblocks, Tom Goetz custom full range speakers -- and just one jazz LP recorded in a live bar with two-mic tube recorder simplicity back in 1957.  The imaging was so real, all you needed was a smoke-filled room and a glass of bourbon and you were "there", transported to the moment lived many years before.  The imaging was simply "believeable" and probably 90% accurate -- enough to totally fool you.  I've never felt anything that real, since.  Mostly, because I gave up on vinyl, sold my vacuum record cleaning machine, and scaled way back when children started coming into my life and the finer things had to go on hold.  In the mid-90s I decided to get back into audio a bit, but with CDs -- just to have some decent sound.  Eventually migrated to my first Zen Select Kit when they first came out, then built a pair of reference quality unity horns, then a WO32 subwoofer, then upgraded to my present Torii kit project which is pretty darn good.  

Source is hardly state of the art -- just a Sony 685V with upgraded power cord and I found a way to take the signal directly off the DAC using the leads of two rather large russian military teflon capacitors to RCAs and into the Torii amp.  

And tube rolling is a synergistic thing.  Sometimes it works, sometimes not so perfectly.

The present window of perfect imaging is pretty much all it can be -- volume and especially balance must be adjusted carefully, the head must be placed quite perfectly between the speakers -- move 2 or 3" away and the sound is still great, but the palpable image begins to breakdown.  Rather like a perfect telescope (another of my hobbies).  The finer the optics in your telescope, the more critical and sharp the focus -- a tiny nudge of the focusing wheel and you see the magic of perfect image go away.  Same with fine audio or at least, my system.  

The magic is pretty darn fine.  So good, in fact, that I plan on relocating my gear to another room where a central listening position will be feasible and comfortable -- assuming the wife agrees -- lol!

My old LPs?  They've been in boxes for about 30 years now.  Never sold them.  Maybe time to think about giving Mr Michell (I was once a dealer for his turntables) a call..... (edited to note I just learned John Michell passed away some years ago now)...

Just might, might make it to the Decfest for at least Saturday -- if I do, I'll at least bring my Torii amp to put it against whatever.... It's doing pretty well, just now.  Rather hope to see you there.  

I strive to give satisfaction, Sir.  Would you like your martini in the drawing room this evening, Sir?  Dry as usual, I presume?  Very good, Sir.  Evaporated spirits ARE exceedingly dry, Sir.