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.
128x128Ag insider logo xs@2xalbertporter
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...

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?
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: and click their English website if you like.