Clash of the Titans


Any members fortunate enough to have beard any combination of the amps listed below?

VTL 750
Tube Research GT 400
Wolcott Presence
Jadis JA 500
Atmasphere MA2 MKll

Your experiences with reliability, performance, power, dynamics, and how it controlled the speaker. Please include short list of associated electronics and favored source.
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This is an interesting query. May I ask what prompts it?
I use a pair of Atma-Sphere MA2 MKII amplifiers to drive Avalon Acoustics Eidolon speakers. I can't comment on any of the other amplifiers listed, so I may not qualify has having heard a "combination of the amps listed."

Over the past year that I've used them, the Atma-Sphere amplifiers have been completely dependable. The amps complement well the speed and dynamic capabilities of the Eidolons, and they have no difficulty with the 4-ohm average load of the speakers. Bass and mid-bass response is detailed, tight and harmonically accurate.

What I've enjoyed most about these amplifiers are their harmonic integrity, transient capability, and ability to make huge dynamic swings. They are able to reproduce acoustic instruments with a naturalness of timbre and rightness of detail and low-level dynamics that sounds eminently "right" to my ears.

Associated electronics: an Aesthetix Io Signature phonostage, with dual power supplies and internal volume contols, directly drives the amplifiers. (And the Io definitely makes a significant contribution to the overall sense of unlimited dynamics.)

Primary Source Material: LPs, 90% classical, almost 100% acoustic.
I use a pair of Atma-Sphere MA2 MKII amplifiers to drive Avalon Acoustics Eidolon speakers. I can't comment on any of the other amplifiers listed, so I may not qualify has having heard a "combination of the amps listed."

Over the past year that I've used them, the Atma-Sphere amplifiers have been completely dependable. The amps complement well the speed and dynamic capabilities of the Eidolons, and they have no difficulty with the 4-ohm average load of the speakers. Bass and mid-bass response is detailed, tight and harmonically accurate.

What I've enjoyed most about these amplifiers are their harmonic integrity, transient capability, and ability to make huge dynamic swings. They are able to reproduce acoustic instruments with a naturalness of timbre and rightness of detail and low-level dynamics that sounds eminently "right" to my ears.

Associated electronics: an Aesthetix Io Signature phonostage, with dual power supplies and internal volume contols, directly drives the amplifiers. (And the Io definitely makes a significant contribution to the overall sense of unlimited dynamics.)

Primary Source Material: LPs, 90% classical, almost 100% acoustic.
Ivanj, to answer your question.

There are compromises with all audio gear and big tube power amplifiers are no different. They are labor intensive to build and subject to many design decisions that must balance performance, reliability and price. Some designers compromise all three, some only one or two.

My reference speakers are the Soundlab Ultimate 1 which makes that choice even more critical. Not the easiest speaker to drive to live listening levels.

I've already owned the Atmasphere MA 2 ( not Mk ll) , the Tube Research GT 400, two Viva's and now the Wolcotts. Speaking with a fellow audiophile today made me wonder I had overlooked (a possible) perfect option.
well if you had tube research 400s , you had the best amps on earth. all the amps you mention are great amps but the tube researches are the ultimate. the u1s are on a very short list of some of the finest speakers on earth as well.
Albert- Your a friend so I'll tell you the way it is, all that stuff is junk. Get yourself some bose 901's and enjoy the music ;) Besides its not like you could hear the differences in that horrible room of yours :) ~Tim
Tim ... the 901s? Nahhh ... old design. Get the newer Bose "Wave" ... yeah, that great radio/alarm clock/high-end player. Be sure to play it in your garage for all that nice reverb, too. *groan*
Dear Albertporter-

I've heard
VTL 750
Wolcott Presence
Jadis JA 500

Listened to the 750 VTLs on Wilson speakers - very spectacular, dynamic sound. I heard them in a shop on the west coast. Levinson front end gear. Very nice system, not my particular taste however. Dealer claimed they are reliable.

I've heard the Wolcotts on Sound Lab M-1s. They made the other (SS) amplifiers the dealer had sound broken. I ordered a pair. The dealer and some others I've spoken to claim the Wolcotts in their present incarnation are very reliable. I sure hope so....what has been your experience?

I've heard this particular Jadis and some others - older versions - on several different speakers including M-1s, big Apogee Ribbons and Audio Physik something. They sound very good indeed. They really sounded fine on the Apogees! My buddy who had a set on his Sound Labs A-3s finally sold the Jadis because they blew up periodically, and at the time, needed lengthy repairs. (He also had several OTL amps over the years; he said their reliability is "getting better but they all blew up.")

He finally gave up and got a set of Boulder amps for his M-1s (he moved up from A3s.) Those sound very good indeed, but are a bit out of my range financially. It's nice to have a friend with a system like that nearby!

BTW I don't mean to gore anyone's particular ox here and I hesistated buying a high-powered tube amp myself so we shall see.
Allow me to chip in with my limited experience.
Jadis: sound can be best desctibed as emminently "musical" for wont of a better word. My experience with smaller models & briefly with 800, is of a very full sound where it's difficult to discern what you do NOT hear, even if listening critically to sound rather than to music. It is indeed difficult to listen to sound only; the music always took the upper hand with me. Reliability: VERY sensitive to the quality of the electricity supplied, so with loder models, small fluctuations could cause large problems ("blow-up"; allegedly, their components are driven to the limit). However, Detlof has such operational problems under control. Surrounding equip with Jadis 800: their own pre (the "big" one), Audio-Physic Medea speakers, Clearaudio ref TT/ Insider. Music was classical 100%, lieder & symphonic. Nordost cabling (spm throughout). Pls note that the Medea has an active servo sub, and 3x Manger drivers on each speaker for mid-high. The amps were driving the Mangers, ofcourse.

Atma-sphere 60W (model??) driving the same speaker. Same set-up; not very good matching s/where. We changed pre to a CAT ultimate, using the CAT phono. Better results, but we never quite matched the whole system -- we were doing s/thing wrong there... Only sonic comment: to me, the CAT/atma combo sounded slightly faster than the Jadis combo.
Reliability from hearsay, I'm afraid: no problem whatsoever from the few atma users I know... they display a "plug & play" psychology.

I have not experienced VTL, Wolcott, and T-Research well enough to comment.

Finally, a Soundlab experience: I was astounded by a smaller model's performance (still full-range panel: 1-2 below yours?) driven by the following unlikely combo: CAT ultimate pre, Symphonic Line Kraft 250 classA monos (ss), S. Yorke "Zarathurstra" TT/Pluto arm/clearaudio Accurate. Nordost valhalla cabling throughout. Music was classical as above, and included mono recordings and some blues. Full-range sound, astounding dynamics from a stat, top & bottom end I had never expected, and the wonderful feeling oof "being there" and not worrying about the sound per se -- just the music. From memory: effortless transients, natural timbres, harmony, and emotion... were all conveyed. (Pls note that while I listened, I wasn't thinking of all this poetic audio-critic mumbo-jumbo.) Magnificent speakers!
For what it's worth, both the CAT pre and the Kraft (particularly the latter) are very dependable...

Cheers!
Albert, I haven't heard them, but I've been told that the Convergent Audio Technology(CAT) JL-1 is a helluva amp. You can use 6550s, EL-34s, or 6L6s in it for your preference. Pentodes wired in triode. Push-Pull. Performs much stronger than the very conservative 100wpc rating. I've read reports of it playing as strong as the Jadis 500, but better. Still not the equal of low powered single-ended triode, but plenty of guts. If you can stand a lower power than that, the Wyetech Topaz using 572s is reported to be a real great one. I don't know if you like 572s or not. Supposed to be better than the VIVA that you had before. BTW, there is a Berning Siegfried 811 ZOTL on the A'gon classified right now. Only $2750. I've always thought that this would be worth a listen. Might not have the extreme power you are looking for, but it is 12 real strong great-sounding single-ended OTL watts. I know you are well aware of the trade-offs involved. Keep us posted on your progress towards amplifier nirvana!
Hi Albert,
I personally think you have to give the Atma-Spheres another shot. They are definately much better than the earlier ones Ralph sent you, besides that they are the most reliable amps I've ever owned. You can listen day after day and know they are going to work and sound great. What more could you ask for in an amp?
Rusty
I got an update on the VTLs, and alledgedly, their "togetherness" is questionable also, whatdayagonnado?
Albert, do you bi-amp your U-1's? You might have overlooked the Double Kronzilla SET monoblocks ($40.000 per pair)
A friend of mine is bi-amping his Martin Logan Prodigy with 2 pairs and I assume if they are heavy duty enough to drive those speakers, they will drive your SoundLab also. And according to him, nothing better for an ESL than a SET amp without negative feedback.
I might be the first person in Germany to set up such a system. I have ordered a pair of Soundlab A-1 to compare the bass against my ML Prodigy in my system in Florida. I have read everything what people say in respect of the bass, so I am very curious how the Soundlab will compete against the Prodigy. But should the A-1 only equal the Prodigy, then the U1-should be the better speaker and I will hook up a U-1 to two pairs of these Kronzilla amps for my German system.
You can read about the giants of SET: www.blackforestaudio.de and click their English website if you like.
Albertporter mentioned specific products in his thread. If sidetracking is allowed, I can follow up on Tekunda's post re: KR enterprises amps. I heard the Medea (see my previous post) driven by a pair of VT 800P (have I got model right?), 40W SET. By far the best sound of the lot WITH THOSE speakers and a CAT pre. Rest of system was same as above. The big "Kronzilla" are more powerful than the 800 it seems.

Didn't mention these amps as they were not on A-P's list -- but they have VERY impressive driving power and transient attack/dynamics. Not sure if bandwidth is restricted in the low end... Reliability is outstanding; the tubes boast s/thing like 20.000- 50.000 hours. No tube rolling though, these are proprietary tubes. Cheers!
Many ideas to consider here.

I just got a call from Mike Elliott to do advertising photography of the new Aria amps. 350 watt monos that are hybrid.

I know since they are Mike's design that the sound will be good. It will be interesting to see how they balance against all tube design.
Gregm,
these Kronzilla are monster tubes. They take about 120 man-hours to make and Dr. Kron its using the help of bohemian artisan glass-blowers. If I may add my two cents and I do not work for Kron Enterprise, these are the most exciting SET amps in existance today. More a piece of asrt than juts an amp. I just spoke to my friend again and he believes that the amps are very well capable of driving the Soundlabs. And he said if anybody understands amps, a SET with zero neagtive feedback is something really special.
I will soon see and hear for myself.
Tekunda, If you buy Soundlab A1 and listen with the Kron please post or send me your impressions via email.

The A1 is almost identical to my U1, so your performance impressions would be valuable. When are you getting the speakers and amps?
Hi Tekunda,
Your experience with Kronzilla + A1 interests me too, immensely. Since you're in Germany, any chance you can try Symphonic Line's Kraft 250 with the same speakers? I've been trying to find the Soundlab model I listened to with the Kraft 250A monos -- but haven't been able to locate the owner... Certainly an A series by the looks of it, and quite tall & wide, so maybe an A-1 rather than A-3.
Cheers
I will definitely post my experiences here, but since my Soundlab speakers are in the process of being built, it won't be before the end of August, before I can post here concerning these amps and Soundlab speakers.
Tekunda, feel free to contact me once your Soundlab speakers are broken in, I have tweaks that will help performance.
Have had the CAT SL-1 for years, have had the Jadis JA-80 for years.
Also had the chance to listen to the Jadis JA-200, and the JL-1 CAT mono's.
I cannot comment on the other US amps. but i can say with full confidence that entering the Atma-Sphere MA-2 mkII in my system has turned my audiophile world upside down.
I experience an openness and lifelike sound which is hardly to describe in technical terms.
the Jadis and CAT amps are very good mind you.
but compared i experience a much wider frequency, and a much more open sound with the MA-2's. Another thing is the drama and the speed of the amps which is staggering.
I partner my MA-2's with a Cello Encore preamp, and listen to LP only.
The MA-2 is the most reliable amp ever had in my 25 years of listening to music.
Use them balanced in any case.
I use the Voce Divina speaker system for some 6 years now.

regards and enjoy the music !