Jadis JA-200 Mk. II Amplifiers

[bonzo75]

Yes, Dato' Danon did choose Vitus to drive the Pendragons (and now the Kodos).

I do not know the Greg story to which you refer.

But I will add another data point in support of your point: Michael Fremer chose the darTZeel amplifiers over VTL Siegfrieds, preferring the slightly more transparent, slightly less bloomy side of that knife-edge between tubes that get close to the tube/solid-state neutrality line and solid-state which gets close to the tube/solid-state neutrality line. I make that fine decision the other way.

And Marty prefers the midrange of the spectral to his Siegfrieds (not to mention other advantages), and you can go to innovative audio and compare spectral and VTL s450 on XLF for midrange.

 

[Ron Resnick]

An important point is the midrange is just not about the valve tone that will be consistent across speaker. The ribbon has to be driven properly for midrange, not just for dynamics. For the vocalist to have the sustain, rise, depth, all of which contribute to the midrange, the ribbon has to be properly driven. There is a reason Krell on scintilla has such a fantastic midrange. So imo your theory of thinking that NAT being a SET has a better midrange than Krell is not correct. This is correct only if you are using them on Zu, verity, and such speakers.

I agree with the direction of what you are suggesting, but not as far as you are taking it, only because the difficulty of driving a Scintilla is either literally unique, or virtually unique, in audio land. I agree that unconventional drivers (whether electrostatic or ribbon or planar-magnetic) generally need a lot of power. I am a proponent of the view that excess power is good, not excessive.

But you are mainly focused on current to energize Apogee woofer panels, and that just is not the situation I am facing with the Pendragon, or the situation any owner of Gary's ribbon panel faces.

I simply am suggesting that the Pendragon ribbon panel, like the Genesis ribbon panels, really are different animals than multi-way Apogees in terms of current requirements.

 

[Ron Resnick]

Hi Ron,

I currently use a pair of VTL MB-750’s in my development system driving a pair of Kef Blades. My guess is the “slow sound” described by some here applies to running them in triode mode with the stock VTL branded 6550 winged c’s and driver tubes. I use them in tetrode mode with TAD (chinese) KT-88’s and driver tubes and I dont think theyre slow at all. The combination does provide for extremely low distortion levels, THD measures below 0.1% down to 70Hz increasing to 0.2% below, THD+N is unavoidably around 1%, still not bad for tubes.
We have Jadis JA-80 mk-1’s in house, currently on loan to a client but when they return I’ll hook them up and report back. I dont think they compare but have not done a direct A/B before. The Ayon Orthos might be an interesting alternative. I recommend threading carefully as the old 750’s are obviously not flawless but they can be very capable amps when setup right.

Thank you for reporting on this! I set my MB-750s in triode mode (after comparing both modes) almost two decades ago and I never switched them back. I did fine the tetrode mode faster and more dynamic but not as smooth and "sweet."

 

[Ron Resnick]

the Ayon was on my radar in the peripheries (maybe a bit less than the Jadis), which is no dig on Ayon at all. i did briefly take a stab at acquiring one particular tube amp, the WAVAC HE-833 (likely the V2), but then i found the musical connection i'd been seeking with some system tweaks and my tube lust cooled. it only cooled, i still have tube lust. i always think about this or that tube amp, but the reality of my system priorities rears it's head. since that flirtation with tubes, I've acquired the MSB Select II, the Tripoint Elite, and i'm on my way to acquire the AS-2000 (and other more modest additions). so i could have pulled the tube amp trigger if it was important enough to me.......obviously i'm just a tube amp wanker/lurker......so pay me no mind.

Hahaha! That is a funny evolution!

I have always been curious about the Wavacs versus NAT Audio Magma. This is only one data point but A.J. Conti owned NAT Transmitters and NAT Magmas, and he said he did not care for the build quality on the Wavacs. (This is all I know on this point.) I do know that he liked the Transmitters and he loved the Magmas.

I do not know if he ever actually owned Wavacs. I do not know if he ever did a direct sound comparison between Wavacs and Transmitters or Wavacs and Magmas.

Also, I think Stereophile measured Wavacs' distortion during the course of Michael Fremer's review of one of the Wavac models some years ago and they found the distortion level kind of shockingly high at a fraction of maximum rated output. But I think most, if not all SET amplifiers measure poorly to very poorly.

 

[Ron Resnick]

Hi Ron. I heard the Jadis JA-200 MKII with Jadis preamp and phono stage at AXPONA 2017. Here is a link from Stereophile.
https://www.stereophile.com/content/jasons-day-one-continues-one-step-closer-oz
I was able to sit center for the demonstration and recall thinking this system sounded really good. The sound was rich and warm, open, had 3D characteristics. Female voice was very good as I recall but can’t remember what I heard. Phillip O’Hanlon’s room was one of the better presentations I heard at the show. The only VTL experiences I’ve had are with Siegfried and I would say that a full VTL system (Siegfried, 7.5 pre, 6.5 phono) that I have heard on Wilson Alexia would be a contender against the overall sound of this system in the same room with the same speakers. My current personal references are Zellaton/CH Precision so the Jadis system sounded less dynamic, extended, and real to me but that is just my personal preference at this time. The Jadis system with Vivid was impressive no doubt.

Thank you for discussing your impressions here.

KeithR reminded me that when we heard the Jadis on Magico speakers at the LA Audio Show I thought (and Keith thought too) it was one of the best sounds I/he had heard from Magico speakers. I also thought Myles' CJ electronics on his S5 Mk. IIs sounded great. So basically I always prefer tubes on Magico!

 

[Ron Resnick]

The bass of the MB750 only showed its limitations when compared to modern VTL's, Atma-sphere's or for example recent Audio Research amplifiers. I always used it in tetrode mode and most of the time in balanced mode. Today I feel guilty of not having upgraded it - but upgrading it needed around 30 signal capacitors and as the original capacitors were small, typical high quality ones from Mundorf or Vcap would not fit the space. The relative lack of detail playing at low levels extended along the bandwidth.

Unfortunately the balanced input was a late poorly implemented add-on - I only discovered it little time before parting with it.

I measured my units - the output transformer was really good , wit low distortion at low frequencies, but overall much higher distortion that current amplifiers. The power supply was exceptional - there separate power transformers for filaments, output power and input/driver.
None of the power supplies was regulated, as in modern VTLs.

I am reporting on sound with Wislon, SF Aida's and Soundlab's - surely with other speakers it can sound different.

All of this makes sense to me. I know the balanced input on the MB-750s is a phoney-balanced add-on, which I why I have always used the single-ended inputs. I think replacing the appropriate capacitors would catapult the MB-750s out of its golden era and into modern times (ah, sound).

And yes -- I understand about the MB-750's bass limitations compared to current production amps (VTL's and everyone else's). In my current, idiosyncratic situation, the Gryphon bass towers relieve the amps driving the ribbon panels from all low-frequency responsibility.

 

[Ron Resnick]

That must have been a nice setup!

Circa 1988: Reference Recording's Symphonie Fantastique spun on the Goldmund Reference turntable with JA200s driving IRS Vs in Lyric's main room was my very first "religious experience" of an audio nature. After that, I was hooked on this hobby!

 

[Barry2013]

I am reminded of my dealings some time ago with THE Jadis dealer here in the UK.
He was a huge fan of their amps and he even had his Jadis amps rewired with platinum wire. I guess that is really what you call OTT.
I haven't been in touch with him recently but I imagine he is still using them

 

[microstrip]

(...) Sure the heart of the amp is basically the same as the JA-80....its not a brand new amp across the board...and why would it be? ( so the amp shares the same chassis, the same basic look, etc) Instead, Jadis has modified their design with better transformers, larger caps, better wiring, and the ability to utilize the new KT150 tube. Is there a problem with that?

OK, it is a question of semantics - I consider that such differences are minimal - they were carried by many users on existing models, as could be expected considering the age of the model. I was expecting that our Jadis experts would have something definitive and solid technically to inform us, as reports I have read seem contradictory.

What is interesting for me is that small modifications and a big change (the KT150) seem to change significantly the sound quality.

 

[Ron Resnick]

Why are we comparing early 1980s amplifiers to a current, recently redone product?

+1

Yes, let's compare amps accurately and intellectually honestly, generation by generation, as the amplifier companies' products certainly have evolved over time with bigger and bigger transformers, better and more transparent capacitors, etc. I am not suggesting that MB-750s or Jadis Mk. I models are as transparent or neutral or as controlling of bass woofers as today's Siegfried IIs or Jadis Mk. II models or any other company's current products.

I agree that we cannot meaningfully compare Jadis Mk. I products or MB-750s to today's current production amps.

 

[microstrip]

+1. I'm not sure the point here and micro uses the opposite argument for other electronics.

Just the transformer difference to accommodate the KT150 is quite a difference - as it is on my ARC Ref75SE. They've also added auto bias, fused resistors, etc. To say there is little difference from a 1983 amplifier i think is misguided at best.

I also say that there is little difference between the SE series and its precedents, or the REF10 and the REF40, although there are significant sound differences. And yes, I inspected and listened to them side by side. In the case of the amplifiers the larger difference was also the use of the KT150.

 

[Ron Resnick]

And Marty prefers the mistake of the spectral to his Siegfrieds (not to mention other advantages), and you can go to innovative audio and compare spectral and VTL s450 on XLF for midrange.

Yes, Marty made what is to me a very interesting swap. Tube pre with fast, neutral solid-state makes sense to me.

But nothing was a mistake. (Maybe I don't understand?)

PS: Interestingly, every Arrakis-based system of which I am aware uses tube amplifiers -- except Andy Payor who formerly used tube amplifiers -- and now uses Gryphon Audio amplifiers!

(All this tells me, once again, that at that level of electronics quality the sonic differences are subtle and subjective and driven by subjective personal preferences.)

 

[Ron Resnick]

So who is going to order Jadis JA-200 Mk. II AND Ayon Audio Orthos XS for the ultimate high-power, Class A, push-pull comparison?

And then compare the winner to NAT Audio Magma New SE?

PS: We would never all be able to agree on which speakers to use for the test!

 

[bonzo75]

Yes, Marty made what is to me a very interesting swap. Tube pre with fast, neutral solid-state makes sense to me.

But nothing was a mistake. (Maybe I don't understand?)

I meant midrange, not mistake

 

[Ron Resnick]

Hahaha. Good!

 

[microstrip]

+1

One of the big problems I think on this and so many other forums, is that members who have not heard the current/latest gear in question, assume (incorrectly) that the piece that they either owned or heard decades ago is representative of the current offering. (...)

FIY my home experience with the JA80 was four years ago (2013) and the amplifier was manufactured around 2007. At that time Jadis informed that there was no significant difference between my amps and the current ones.

As the Audio Research and the Wilson distributor also distributes Jadis in my country I regularly listen to recent Jadis products - the last one was the excellent DA88S integrated. When he gets an JA80 mk2 I will probably also listen to it.

 

[microstrip]

I meant midrange, not mistake

Funny mistake!!!

 

[LL21]

Yes, Marty made what is to me a very interesting swap. Tube pre with fast, neutral solid-state makes sense to me.

But nothing was a mistake. (Maybe I don't understand?)

PS: Interestingly, every Arrakis-based system of which I am aware uses tube amplifiers -- except Andy Payor who formerly used tube amplifiers -- and now uses Gryphon Audio amplifiers!

(All this tells me, once again, that at that level of electronics quality the sonic differences are subtle and subjective and driven by subjective personal preferences.)

Interesting...i do like tube pre with SS power. I have read about this combination before...it happens to suit me, but I am sure that all combinations can work depending on equipment and system. As for the Arrakis, the system I have heard myself used 4 VTL Siegfried Ref Monos. The Arrakis systemsi have seen online are Gryphon Mephisto, VTL Ref Monos or D'Agostino Ref Monos. I have spoken with Andy Payor who loves Gryphon...I have seen on his old website CJ mono amps as well.

 

[DaveyF]

FIY my home experience with the JA80 was four years ago (2013) and the amplifier was manufactured around 2007. At that time Jadis informed that there was no significant difference between my amps and the current ones.

As the Audio Research and the Wilson distributor also distributes Jadis in my country I regularly listen to recent Jadis products - the last one was the excellent DA88S integrated. When he gets an JA80 mk2 I will probably also listen to it.

Micro, i was not specifically discussing you in my post, but as they say...” if the shoe fits”; lol.
Listening to an amp that was manufactured 10 years ago is getting exactly to my point!
Please go out and listen to the new Mk2 if you get an opportunity, and then get back to us...

 

[ack]

Circa 1988: Reference Recording's Symphonie Fantastique spun on the Goldmund Reference turntable with JA200s driving IRS Vs in Lyric's main room was my very first "religious experience" of an audio nature. After that, I was hooked on this hobby!

The RR Fantastique remains the best recording in my collection; I can only imagine what your experience must have been like!