Jadis has a cult following because of its wonderful midrange etc.It is truly one of the great tube amps with supper transformers and build quality.Mr Anus is pissing in the wind just because he is a reviewer for Stereophile and likes to get things at 50% off doesn't mean he is the last word in audio.Been in this hobby over 50 years never let a reviewer sell me anything as its my ears and my wallet.Good luck!!
I think all the review should be read to say is that the JA 200s are not an ideal match for the Wilson Alexias, at least in the reviewer's opinion It's a shame that the reviewer didn't have other speakers on hand to see if the problems were with the amplifiers in general or were related to their interaction with the speakers. I note that Art Dudley, to his credit, did a follow-up to his review of a Peachtree amplifier when he considered the distributor's point in the manufacturer's comments that Dudley's vintage speakers were not an ideal or typical match for the amp.
Indeed, I am very happy with the midrange reproduction from my new Jadis amps. However, the lows and highs are equally as impressive on my system, the amps are tremendously ‘resolving ‘. More so in fact than any other amp I have had in my system. My amps are strapped at the 4-8 ohm strapping and the KT150’s are easily able to drive my speakers. I had no concerns about the amps ability to drive my speakers, and unlike JVS, my speakers are a much easier load. (Although not one that any flea powered amp could be happy with). JVS doesn’t seem to understand that the “marriage” between gear is paramount in the result that one will get...probably due to his lack of experience. Imho.
This review is a true disaster in my opinion.
I own this JA200 MKII on KT150 tubes and know their sound very well. It is amazing sounding amplifier. It must be used with quality preamplifier.
The reveiewer made so many mistakes that should simply apologize for their job. Powering this amp directly from DAC, using Wilson Audio and Nordost cables is a short way to screw up the sound.
I agree 100%. One of the worst reviews I've ever read. Why only one speaker model was auditioned with this amp is a mystery. I'm not a Jadis owner but I have tube amp experience. A tube amp configured at 1 ohm certainly will sound like crap in the top end. I tried the 2 ohm tap from my VAC amp into N802's and it was dull, boring, and lifeless. I would bet the results would have been much better using the 4-8 ohm tap even if the speaker does dip to 2 ohms at one point in the bass. Why try to optimize this this one impedance at the the expense of the rest of frequency range?
But then again, why did Jadis supply the amp this way?
There is plenty of blame on both sides. Stereophile should do a follow up with a different reviewer, speakers, and proper impedance match.
The review concludes with the following:
For beauty of sound, the JA200Mk II monoblocks have few rivals. They're extremely quiet and fast, and their midrange, neither over-emphasized or bloated, is to die for.The amps were delivered and setup by a principal of Jadis who knew ahead of time what equipment they were to be paired with. The manufacture or distributor configured the amp to its one ohm setting.
I suspect most Jadis owners would use a preamp, but the $35k dCS is a DAC/preamp of exceedingly high quality. None of the specs would suggest a mismatch of any sort.
Overall, the article is more a comparison than an outright review. The reviewer is probably accurate in the sonic differences between the Jadis and Pass in his particular system. Considering the weight and size of the Wilson loudspeakers, it's probably not very practical for the reviewer to swap out loudspeakers.
It is what it is, the review says the Jadis sounds wonderful, but different than the Pass solid state. Would anybody here feel better if he concluded the Jadis sounded just like the Pass?
Onhwy61, just one problem...is it not the reviewer’s job to try and make sure that the gear under review does NOT have a compatibility issue with his existing gear?...and if so, report on that fact!
If JVS speaker’s were not ideal as far as a match with the Jadis amps, and as you say the speakers could note easily be replaced, would it not make more sense for another reviewer to take on the task? A reviewer with more experience and with more compatible gear. Failing that, a disclosure that the amps were not at their best due to the speaker/amp mismatch.....just a few of my thoughts.
Towards the end of the article the writer points out that the manufacturer doesn't think there is a compatibility issue with the loudspeakers that would result in what he is hearing. And I'll state again that Jadis knew ahead of time what loudspeaker the writer was going to use and configured the amps to what they thought would be the optimal setup (KT150s/1 ohm). It would be interesting to hear the combo with a different amp configuration to see what effect it would have, but it doesn't appear that the manufacturer/distributor made that suggestion. Maybe next month's issue will have a manufacturer's comment.
My take away from the review is that the amp made beautiful sounding music with the Wilson, but that it might not be the amp for someone seeking Hi-Fi thrills. French sophistication at its best. What more could a discerning music lover want?
BTW, what loudspeaker are you using?
bdp24, I think you have an excellent point there. Although I suspect that most readers would know that Altec Valencia's have a very specific sound....which may or may not appeal to everyone.
Onhwy61, I did not see anywhere in the article a reference to the fact that JVS was listening to the amp with KT150's and also with the 1ohm setting....1 ohm setting yes...but with what tubes?? The photos of the amp only show it with KT120's???
JVS does state at the end of the review..." neither Thomas J.Norton's measurements of the amplifier's predecessor ( what this has to do with the current amp's measurements and specs is questionable, IMO) nor Jean-Christophe Calmettes himself suggested that that might be the case" ( In reference to JVS Alexia's being bass shy). However, this presumes that Calmettes himself was aware of JVS feelings regarding the bass shyness. ( which he possibly did not,as he apparently does not have the best understanding of English!) If he did, I cannot imagine why he would not be concerned about the very low impedance drop issue.
BTW, my speakers are Sonus Faber GH's....an excellent match with the new Jadis JA30Mk2.
soundsrealaudio, I would suspect that the new Jadis amps would work very well with the Vivid's. IMO, the sweet spot of the Jadis line is the amp that I now enjoy...the JA30Mk2; not sure if this would have enough grunt to drive the larger Vivid's...like the G2's or above, but if it did, I would bet it would be a killer combo.
FWIW, after re-reading the review, it looks to me like the only person who knew the amps were strapped for one ohm was John Atkinson, and only after he opened up the amplifier--he notes that the distributor had stated they were in the 4-8 ohm setting. And the reviewer says that the manufacturer rep installed KT 150s, and JA stated he measured the amps with KT 150s, and I must assume that at least JA knows what KT 150s look like, so perhaps those are stock manufacturer/distributor photos in the article (they certainly have the look of them--compare the photo quality of the amp shots with the photo of Calmettes)?
In an ironic way, this will potentially prove a good review for Jadis.
Every month, these magazines feature a half dozen or so components. Rarely does anything happen beyond the company using the review on their website to prove its worth to those already well on the road to considering it for purchase. How often do we discuss the review in forums like Audiogon? In other words, does it pay real dividends? Does it create buzz?
Here we are talking about a review / component / company, with the overwhelming majority of folks standing up to take notice, and defend Jadis. That’s a rare occurrence, and likely an unintended positive outcome few would have predicted. I can’t remember how long it’s been since a more diverse and spirited Jadis discussion came down the road. Quite possibly, Jadis will get their money’s worth and a whole lot more from this review
I seriously doubt, knowing the Jadis amps, that the DAC that JVS was using will have enough output to really drive the amp...while this may work with other amps...like a Zesto BIA. I think a great deal of what JVS heard can be attributed to a mismatch between the JA200mk2’s and his ancillary gear. Plus, it would not be my first option to set the amps up at their 1 ohm setting.
Relating that the amps were lacking in the bass and upper frequencies would certainly lead me to believe that something was very wrong with the set up. Of course, we are assuming that the amps were being used with the KT150’s, which is not entirely clear.
And I repeat, the manufacturer/distributor set the amps at 1 ohm, not the reviewer, and it was certainly not incumbent on him to open up the amps and reset the amps at a different setting. That's easy enough when you have separate taps outside the amp like ARC and VAC do, but not obvious or easy with Jadis. According to JA on his measurements section, the distributor told him the amps were set to the 4-8 ohm setting; if there was a mistake, don't blame the reviewer. If anything, I'd like to have the distributor resubmit with the amps set at 4-8 ohms and see how that works.
As far as running the dCS right into the amps, my experience with all amps I've used, not just my old JA80s, has been to prefer the sound with a preamp in the chain (especially a Jadis or similar quality tubed preamp), although they certainly weren't lacking for highs or lows when I tried a passive volume control with them. However, there are a lot of people in these forums who prefer running their DACs right into their amps, as any search in the forums will show. I would like to have someone like Al look at the specs and see if there really was a mismatch between the Jadis and the DAC that would explain the reviewer's observations, but unless you can show us one you're just speculating..
The review does highlight the great strength of Jadis electronics, a wonderful midrange. Even with rolled off highs and a full but overly ripe bass, my JA 80s were in my system for well over 10 years with a less than optimal speaker match (Duntech Princesses) simply because the midrange was that good. Jadis really isn't for the person who wants aural thrills, and I would also submit that their products are more geared to the person who listens to acoustic rather than rock/electronic music. Michael Fremer (I think correctly) pointed that out when he reviewed the JP80MC preamp years ago.
Ultimately, you made an excellent choice getting the JA30s (which, by the way, in my view have the best bass reproduction of the Jadis amps, at least in their original version), I'd not worry about the review. A person who knows the reputation of Jadis and what they are best at won't be scared off by the review (unless maybe if they own Wilson Alexias).
rcprince, since I am very happy with my new JA30Mk2’s, I have no intention of selling them....and as such I couldn’t care less whether the review impacts Jadis values or not. However, I do think that the JA200Mk2 review was very poorly done and shows the inexperience of the reviewer. IMHO, an amp should be able to do it all...and not leave some aspect of music production on the table. ( Yes, i know this is a very lofty goal, but any gear that is able to produce a wide range of sounds...from the deepest lows to the highest highs, should be looked upon as superior to any piece of gear that is limited to just one area of the audio spectrum---even if that area is the most important midrange and superbly reproduced!)
Setting the amp back to the 4-8 ohm strapping is not hard to do on the Jadis amps, and I do feel that the reviewer fell down here. It clearly states in the owner’s manual how to do this. Whether the amp was set up at the factory in this manner, I have no idea ( if so, that was a huge mistake IMO), but I believe the new amps are shipped with the standard 4-8ohm setting in place.
As I let my subscription go after a multi-decade run, I went out to buy the current review. I canceled Stereophile and TAS as the reviews leave me cold in comparison to earlier days. But at $9.53 after tax for a single copy, it obviously pays to keep the subscription for the annual $12.
To get a more complete picture, I also returned to the previous Jadis JA200 reviews by Dick Olsher (1993) https://www.stereophile.com/content/jadis-ja-200-monoblock-power-amplifier and Jonathan Scull (1994 + follow-up in same year) https://www.stereophile.com/content/jadis-ja-200-monoblock-power-amplifier-jonathan-scull-review Though not a fan of J10 back then, I encourage folks interested in the decline of high-end audio reviewing to do likewise. I bemoaned how things moved backwards back then, and they’ve gone a lot further.
Funny, when these older reviews came out, the $18,900 price tag struck me as ridiculous to the point of obscene. Yet in today’s world of five figure ubiquity for uninspiring components, dare I say $33,900 for these amps almost feels like a value component? How the world has changed... Regarding the output tubes in photos, except for JVS’ system, they feel like the stock photos the magazine all too often employs. Folks have long criticized Stereophile’s lack of review visuals. The magazine declared in the 90s they would put right, yet still have not. That only comes off as more surprising with today’s digital cameras, iPhones, and the like.
I’ve never liked Nordost cabling, but the company’s obviously sold a lot of it. The digital front-end doesn’t present anything untoward to me, and would look to the Wilson Alexias as an interesting partner. Having JC Calmettes personally show up to (suboptimally, 1R OT strapping and all) set up the amplifiers in the system became a point of failure for whatever reason. The previous reviews begin to show how far the product moves forward in the hands of a determined reviewer (or owner). Beyond the Nordost power cords, JVS took to pen and paper using the amplifiers more or less out of the box. I’ll agree to anyone asserting that’s the reviewer’s job, review the product as received. Fair enough. In fact, expected.
Have things reached a point of reviewers offending by not praising a component up one side and down the other? ALL components have flaws, and ALL can find criticism. Perhaps my biggest problems with the high-end audio media rests with reviews failing to deliver honest assessment. Some label such writing advertisement.
Anyway, in no way would I label the JVS review of the Jadis JA200 a SLAM. onhwy61 makes a good case. The review contains liberal use of the highest of superlatives. Any company would lick their chops over coming home with that many gems to run in ad copy. In fact, with all three reviews in front of me, the current comes across as the most positive. I predict the Jadis JA200 finds a place in Class A when the April Stereophile’s Recommended Components appears.
Apart from the review itself, if anyone cares, as one who’s had Jadis products in my system over the past 2 decades:
1. When tube amplification returned to prominence in the late 90s, we heard they didn’t live in the plug and play world, and required actual care and feeding. As I mentioned, while one may not need to emulate Jonathan Scull, Jadis amps demand something of the owner to hear what they can honestly do
2. As much as any, and more than most, Jadis components sonically reflect the tubes one uses in them.
I’ve long claimed their amplifiers sound best running EL34 output tubes, and recommend JJ E34L, specifically. Interestingly enough, Dick Olsher came to the same conclusion with those same E34L besting the big tubes. For those willing to pay for them, vintage Mullards take things up 2 - 3 levels.
12AX7 drivers sound equally as important as the output tubes. Not sure what the factory currently employs, but in my experience, it’s always new production, and European, at that. Outside of the Chinese (Shuguang + Psvane) triple mica variants, current production falls far behind vintage offerings. Input tubes also need consideration, and I’ll leave it at that
3. I’ve reached the point of not preferring bigger amplifiers. Forget about the heat, space, demands on the home’s electrical system, electric bills, or retubing costs. The increase in parts detracts more than the potentially additional muscle offsets. Of course, some loudspeakers and rooms do need more power...
Having tried a number in my system, the sweet spot for me in the Jadis lineup lies in some of the 2 (Orchestra Reference) and 4 (DA88S + JA80) tube offerings
4. Jadis products do not produce neutral sound. Call it a flaw or whatever. One seeking absolute neutrality or accuracy (whatever that is) would best look elsewhere. Jadis produces a euphonic sound, though not in the pejorative it’s taken on over the year to denote lushness, richness, slowness, bloat, or products that claim "tubelike" virtues because of same.
As folks have said here, for the right person and system, a Jadis can provide as much happiness as anything out there
Trelja,while I agree with most of your points..particularly the interesting point about the cost in the past and our perception of that vs. today; I think you are showing us that you have not actually heard any of the latest Jadis amps. The new KT150 based versions are far more neutral sounding than any of the amps that came before from Jadis. So, while the latest models may not be as warm as in the past, they are certainly different sounding than even from a few years back.
Another thing, when JVS states:" the double basses that give the urgency and dread to the symphony’s opening were hardly audible through the JA200 mk2’s" I don’t think this is at all positive...and his conclusion....
"But those who put a premium on brilliant highs and resounding bass may prefer to admire the sounds of the Jadis amps for a hot date or two, without committing to a long-term relationship"...would be at best a ’back-handed’ compliment and easily conceived as a slam. All IMHO.
Excellent thread here in many aspects. I haven’t read the review.
I have owned the current version of the Jadis Orchestra Reference for one and a half year now and am quite puzzled how often people refer to Jadis amps as not being ’neutral’. What is neutral? A colder, more tight sounding thing going on? In that case solid state is more neutral.
I run mine with the factory installed tubes (EH KT90s and Tung-Sol 12xa7s) with Shahinian Compass speakers. I’m sure if I installed EL34s I’d get more midrange with the amp. I tried to tube-roll the 12xa7s but soon came back to the factory installed ones.
With my current set-up bass, mids and treble sounds quite balanced to my ears and this is the best amp I’ve ever owned. It really plays music. I find it resolving, superb soundstage and great dynamics. It just sounds right.
I’m currently planning to buy a Jadis DPMC phono stage. Any users here?
@daveyf, I think you are showing us that you have not actually heard any of the latest Jadis amps. The new KT150 based versions are far more neutral sounding than any of the amps that came before from Jadis. So, while the latest models may not be as warm as in the past, they are certainly different sounding than even from a few years back."
You’re right. While I’ve been around some of the KT120 offerings, I’ve not yet heard the amplifiers running KT150 output tubes. I’m not much of an ARC fan, but know a guy who moved from 6550 to KT120 to KT150 in his amplifier. Although I certainly still have no interest in that product, the KT150 readily eclipse the other two in it. But I also haven’t ever felt interested in buying a set for myself, either.
@howthefidelity, "I’m sure if I installed EL34s I’d get more midrange with the amp."
Yes, but at the expense of the low-end. Still, those JJ E34L are the tubes I run in mine. Unlike the more expensive amplifiers, JOR uses the Dynaco circuit, with fixed bias, and a completely (more neutral) different sound than its cathode bias big brothers. That said, that circuit with the right EL34 tubes produces some of the most glorious midrange attainable that even the more expensive products cannot touch.
What 12AX7 have you tried so far?
@trelja, regarding 12ax7s I tried some old Mullards that I have. They sounded great but overall changed the balance in a way, where I preferred the synergy with the Tung-Sols. It’s been a while, so I can’t recall pros/cons in this case.
Your fixed vs cathode bias design explanation makes a lot of sense. I feel and hear in my current system synergy the JOR works great as is (KT90) and I tune my sound via the phono stage, cables, cartridge and so on. Also the fact that it takes a visit to an amp-tech to bias the damn thing makes me want to keep it pretty stock. But again, this is hi-fi and can change pretty quick and before you know it I may have JJ E34L running in the JOR :-).
Do you know how much power the JOR uses at idle?
Regarding the original topic of this thread it just shows how important it is to always test gear in your own surroundings.
@howsthefidelity, you’re right about the Mullards. Please give the Shuguang (or Psvane) triple mica 12AX7B aka Silver Dragon a go. At $10, you will absolutely not believe their performance. They easily best the Mullards, and compete with the best ever variants. Impossible sounding, I realize...
A journey of building and modding amplifiers completely rewrote my thoughts and beliefs, and I now feel fixed versus cathode bias sits among the top of the factors of how a tube amplifier performs and sounds. Fixed bias sounds a lot tighter, faster, reactive, and neutral. Cathode bias sounds more relaxed, warm, liquid, lush, romantic, and slower. Neither presents a better or worse presentation, it’s why they make vanilla AND chocolate.
If you can handle working around high voltage, you can easily bias the JOR yourself. The effort lies in taking it apart, and (especially) putting it back together. Removing the side panels and bottom plate, simply rest the amp on its side on something like a piece of carpet, with the power transformer sitting on the lower side for obvious reasons. Measure the voltage across the ~5.6R resistor that sits between the output tube’s plate (via the yellow wire) and the output transformer. Adjust the potentiometer to 90 - 120 (Jadis considers 110 best) mV, and you’ve biased the tube. Repeat for the other 3 output tubes, and you’ve biased the amp. There’s an additional step some employ, but as it confuses the heck out of people, and rarely yields anything, let’s disregard it. Beyond this, the figures I just listed leaves the amp biased extraordinarily (and surprisingly at 40% plate dissipation for an EL34’s rated 25 watts, and far colder for your KT90) cold, which Jadis acknowledges. Personally, I bias the amp a lot hotter, though still conservatively, but I won’t say anything further than that for now. Also, I’ve suggested folks consider cutting holes in the bottom plate that line up with the bias resistors and potentiometers, as the ability to bias the JOR without taking it apart would reduce it to something that takes just a couple of minutes.
Officially, the JOR uses 300W at idle.
@trelja thanks a lot for the pre-amp tube recommendation (I'll check those tubes out) as well as how to bias the JOR. I could bias a new set of tubes myself but it's more taking the amp apart that worries me and why I better leave that for the tech. Also I expect the KT90s to last for at least 3-4 years and a general check-up can be done also when installing and biasing the new set of tubes. My sound preferences is definitely towards the fixed bias designs.
Jadis refers to 300W at maximum. I don't believe (or hope that is) it draws so much power at idle. But maybe I should just contact Jadis.
daveyf, the Ja200 MKii amps in the review belong to us. They are currently driving the most difficult speakers to drive on planet earth, MBL 101E MKII. The highs are mind blowing and the bass is as good as with 2 pairs of MBL N15 mono blocks in bi-amped configuration. In fact, it is the first time that I dare to demo those speakers with tube amps.
So, the mismatch with Wilson makes no sense to me. After all, we have all seen them driven by 18W Lamms (not that I agree with that idea). The problem might have been elsewhere. I have owned DCS DAC in the past and never liked it preampless. I found it's digital volume control lacking dynamic drive. It always sounded significantly better going into the CAT JL2 through the CAT Legend preamp that I had at a time - you know what I am talking about since you own one of those.
At Axpona, When Jason first heard the amps and asked to review them, JA200Mkii were driven by Jadis JP200MC 4 chassis preamp.
Kyomi_audio, you make some excellent points. Although I think we have seen Lamm single ended amps (read low powered) drive Wilson speakers like the Alexandria’s quite well..that is not so for the far less efficient Alexia’s.
Nonetheless, I think the real issues are coming from the fact that JVS utilized a DAC as the front end driver....why on earth you would do that escapes me??
Unfortunately, J Calmettes was apparently at the meeting and apparently did not object to this strange pairing. I have no clue why he wouldn’t have had an issue with this, and at least have suggested (strongly suggested) a preamp...like the Jadis that you are utilizing,or another brand. (Again, like you said..CAT).
One of the reasons that I knew the JA30 mk2’s would have no trouble driving my medium efficient SF GH’s, is the fact that they utilize an amazing transformer...plus I have the ability to correctly match the impedance to the speaker load. However, under no circumstance would I consider running the amps from my DAC into the GH’s..even if it were the latest MSB select 2 DAC....which the Dcs certainly isn’t.
Good to hear that you are getting great results with the MBL’s...an unlikely pairing that I wouldn’t have expected would be synergistic.
@kyomi_audio you make some excellent points, and I agree with you. The JA 200 MK2 should have no issue whatsoever driving the Wilson Alexias.
The Alexia may prove a bit more demanding than the WATT/Puppy and its successor, Sasha. But I've heard several instances of those loudspeakers driven to more than good effect by the JA 80
Well, I think we now know why the amps were strapped for one ohm. I had heard an earlier version of the mbl 101s driven quite well by the original version of the JA500s years ago (6550 output tubes), but I still thought it would be hard to imagine them driven with anything less powerful in tubes, glad to hear I was wrong. Would love to hear that combination, especially with the JP200 MC (had to sell mine when I downsized, I still miss it).
rcprince, you are correct, I was experimenting with straps. However, I heard no audible difference between 4-8ohm and 1ohm settings - at least not a significant one. That is why I did not bother to change them back to 4-8ohm setting before shipping the amps to JVS. I can reassure you, it would have no affect whatsoever on the outcome of the review.
You are more than welcome to visit Chicago and hear the JA200/JP200/101Mkii combination. It is quite remarkable.
George, you should remember that ALL speakers react differently regarding the impedance interaction with the driving amp. Therefore, unless you had the exact same pair of speakers that JVS was using, your results with a different speaker are going to be wildly different.
While you may NOT have heard any significant difference with the speakers you were utilizing for this test, that cannot be said for what JVS heard with his set up!
I would highly recommend that one of the reps for Jadis ( or you?? ) request a follow up from Stereophile; this time allowing them to do the set up in regards to the strapping and other items. ( hopefully someone over there would have the experience required to mandate a preamp in the front end!! ---or perhaps the Jadis rep or you can!).
The Jadis JA200Mk2 review---or slam!
Who in their right mind gives a tube amp to a reviewer with speakers that have a .9ohm EPDR loading in the bass, this is an admin cockup.
This is what I wrote in the comments at the bottom of the Stereophile review.
"The reviewers Wilson Alexia are full range passive (no active bass) but that bass can go as low as .9ohm EPDR, I can't see any tube amp even this good one getting the very best out of the Alexia's bass, like a big current pumping solid state could do."
Then you can read between the lines of the reviewer.
georgehifi, would the absolute confidence of your highly opinionated post indicate that you have heard the Alexias with ALL muscle tube amps such as Jadis JA200, Ja500, CAT Statements, VAC Statements, VTL Siegfrieds, Tube Research and others? I am sure everyone here would love to hear your impressions:)
As fas as "Who in their right mind gives a tube amp to a reviewer with speakers that have a .9ohm EPDR loading in the bass, this is an admin cockup" comment - are you part of the industry? Do you know how the reviews are generated and arranged? Maybe you could teach us amateurs a lesson or two??!!!
Being a retail outlet for the Jadis, you need to get off your high horse and read a bit more carefully, I’m not saying the Jadis’s are crap, what I’m saying is a review was done on them saying the bass wasn’t up to scratch.
"the bass was also quite good"
"the bass less full"
"the double basses that give extra urgency and dread to the symphony's opening were hardly audible through the JA200 Mk.IIs."
But this was because of bad component matching, not the amps which I’m sure sound magnificent with the right speaker. They did the same with the review og the MkI of these, I think maybe they just have it in for Jadis.
If you did your homework, I have a reviewer friend, who had/has both MkI and MkII Alexia’s and we have tried many different amps on them and I can confidently say that a tube will not get the best from their .9ohm EPDR loaded bass.
Even the mighty JC1 Halo monoblocks were bettered by the Gryphon Antillion Evo’s and there’s no tube around that could hold a candle to these into low impedance’s and give that amount of current needed into that load.