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... Harman-Kardon Citation II amps, run in mono for 120W/ch, instead of these any day.
Description: Tubed, push-pull monoblock power amplifier with separate power supply. Inputs: can be ordered unbalanced (RCA) or balanced (XLR). Tube complement: ten 6CA7, KT88, KT120, or KT150 (choice of matched tubes on request, requires internal modification at factory); one 12AU7 (ECC82); one 12AX7 (ECC83) in driver stage. Outputs: 2 pairs binding posts in parallel to permit biwiring. Output power: 170W at 1kHz, 3% THD. Output impedance: 48 ohms, set at factory, adjustable by internal coupling from 1 to 16 ohms. Input impedance: >100k ohms. Bandwidth: 20Hz30kHz, 3dB. Sensitivity: 910mV. Power consumption: 500VA.
Dimensions: 11.8" (300mm) W by 11.4" (290mm) H by 26.8" (680mm) D (each chassis). Weight: 121.3 lbs (55kg) net, 143.3 lbs (65kg) shipping (both chassis).
Serial numbers of units reviewed: 113248, 113249.
Finish: Brass and stainless steel.
Price: $33,900/pair. Approximate number of dealers: 12. Warranty: five years, lifetime (transformers only).
Manufacturer: Jadis Sarl, 5 Chemin du Pech, 11800 Villedubert, France. Web: www.jadis-electronics.com/fr/. US distributor: Bluebird Music Ltd., 100 Military Road, Buffalo, NY 14217. Tel: (416) 638-8207. Web: www.bluebirdmusic.com.
... Harman-Kardon Citation II amps, run in mono for 120W/ch, instead of these any day.
I'm outa touch, I'd thought that the bigger Wilsons all had Servo Woofers. Hmm How do they get away without Woofer control ? Of course a Solid State Amp's dampening is mandatory.
Mr.JVS ends up confirming the Pass excellence, like everyone else.
Tony in Michigan
ps. there is an Engineering document covering Audio Output Tube spacing, I think the minimum gap is far greater than glass to glass ( which looks like a Submarine Missile Launch arrangement )
... is rather tightly packed, but there are perforations in the chassis between the tubes to promote air flow.
https://i1.wp.com/i1190.photobucket.com/albums/z446/sthull/CES13/Part1/CT6A6117.jpg?resize=640%2C427
Egads,
Audio Research looks like ( a ) Schiit !
I'll pass.
It seems a bit outrageous in appearance, like a razor wire tattoo ( around the neck ) kinda thing.
Maybe I'm too Old-School to appreciate the lack of Gage.
The way Woo Audio does exposed glass Tubes in their FireFly is stunningly beautiful, isn't it?
I'm a tube fan, especially in Microphones used for Studio Recordings of Vocals. Tubes in Pre-Amps are one of my favorite things. Tubes in Amps have never performed well for me, with the ( only ) exception being the Conrad-Johnson MV-45a driving MG2 Maggies with Music Hose MIT750.
The Tune Audio Avaton Horn Loudspeaker gets Tube amplification and is flat out addictive. ( leave your financials in the Safe or you'll kill yourself to own it )
Exposed tube are silliness from trendy MeToo's
Tony in Michigan
ps. William Z is turning over in his vault.
No Servo Woofers ? new
Submitted by tonykaz on February 2, 2018 - 1:59pm
"I'm outa touch, I'd thought that the bigger Wilsons all had Servo Woofers. Hmm How do they get away without Woofer control ? Of course a Solid State Amp's dampening is mandatory."
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 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.
"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. While I can't confirm that this bass shyness was due to the Alexias' impedance dip down low"
Cheers George
... a pair of the Parasound JC-1 amps.
>4kW output into a 1Ω load.
https://www.stereophile.com/content/parasound-halo-jc-1-monoblock-power-amplifier-measurements
I had them way, way back in my pre-Stereophile days. Given that I'm reviewing different equipment each month, as well as reviewing recordings and covering audio shows and teaching about opera and art song and covering concerts [see https://classicalvoiceamerica.org/2018/02/03/a-too-emotional-violin-concerto-played-to-the-hilt/ -- I'm really proud of this review] and plays and writing concert previews and..., auditioning extra products is not so easy.
The good news is, the Wilson Audio Alexia 2 loudspeakers, with a nominal impedance of 4 ohms that dips to 2.8 in the bass, demand less of an amplifier. Review and follow-up of those speakers to come.
... of the Wilson Audio Alexia Series 2.
Will also need to see the phase angle test results to determine just how severe a load might be presented by that speaker.
Parasound versus Pass Labs makes a fascinating comparison. Both John Curl and Nelson Pass have identified certain (and different) aspects of the amplifier distortion spectrum which each seeks to optimize in order to achieve a specific sound quality. JA should try to arrange a simultaneous video interview with these two designers.
Regarding driving the Jadis amp from the dCS DAC, no compatibility issue is evident based upon the specifications. The Jadis has an input impedance of >100kΩ and an input sensitivity of 910mV. The dCS can drive a load as low as 600Ω (with 10kΩ-100kΩ being recommended) and can be set for a 2V full-scale maximum output - more than enough to supply the specified 910mV.
Without utilizing an upstream preamp, you have NOT heard what these amps are capable of. IME, this is always the case with tube amps...and most ss amps as well! Your Dcs DAC was a very poor choice to drive these amps! Strapping the amps for a 1 ohm load, more than likely not the best solution either...the 4-8 ohm strapping would have been more appropriate. I would strongly suggest a follow-up review; this time with a decent preamp upstream and different strapping. I suspect ( strongly) that your opinion of the bass response and the treble concerns would be ameliorated.
Commenting/reviewing mismatched components is not really fair to the component manufacturer under consideration. All IMHO.
a. The choice of strapping was made by the manufacturer and dealer. You may wish to correspond with them. They had the opportunity to request a follow-up review in Manufacturer's Comments, and did not do so.
b. Why is the dCS gear a poor choice to drive these amps and other amps? I have certainly had no problem with any of the SS amps I've reviewed so far. Why are the products mismatched?
FYI, for my next two reviews where a preamp is definitely required, I have been sent a loaner two-piece Lamm preamp. How I'm going to fit it on my rack will be determined shortly.
Ok, you actually brought up a good question...why is the Dcs a poor choice to drive these amps...and not ss amps? I believe it is a poor choice for ALL amps. The Dcs is designed as a DAC...not as a preamp. ( BTW, the ONLY DAC that might qualify SQ wise to drive an amp is the new MSB Select DAC; and as you may know, the Dcs is not in that league at all) A great preamp will have the DRIVE to handle a tube amp...like the Jadis 200Mk2's. The Lamm's you are going to be receiving would certainly qualify in this way. Pair the Lamm's and the Jadis and you would have a much better idea as to what the Jadis can bring to the table. Why are the products mismatched...YOU SHOULD NOT HAVE TO ASK THIS QUESTION!! Pairing a very difficult to drive speaker ( ala WILSON ALEXIA's-- which have a brutal drop in their impedance in the bass) with a tube amp is asking for trouble, IME. You heard what the combo brought about..along with the mismatch of the DAC!! Wake up man...it's horses for courses in our hobby. Would you pair an Apogee Scintilla with a 3 watt flea powered SE amp??? You would IF you do not believe in such a thing as "mismatching'!! --and were inexperienced in the hobby.
BTW, the dealer you mention ( who shall remain unnamed) sold a friend of mine some lower powered Jadis amps for his difficult to drive Gamut speakers( which the very same dealer also sold -- and we are NOT talking about cheap speakers here) Knowing full well the size of my friend's room...Do you think this very same dealer is going to get any of my friend's future business??
If, as you say, the manufacturer has not requested a follow-up, they are making a serious mistake. However, considering they are out of country, that may be a reason. Although, i cannot comprehend why their rep in the US is not all over this!!
I have no answers for absolute statements such as "the ONLY DAC that might qualify SQ wise to drive an amp is the new MSB Select DAC; and as you may know, the Dcs is not in that league at all," and "If, as you say, the manufacturer has not requested a follow-up, they are making a serious mistake."
Have you considered a job as an audio consultant?
I’m not considering a job as an audio consultant, but I may have to consider the job opening for an audio reviewer. LOL.
BTW, have you actually heard the new MSB Select DAC...doesn’t sound like it, otherwise you would understand why the difference can be stated as an absolute.
Submitted by Jason Victor Serinus on February 6, 2018 - 4:29am
"Wilson Audio Alexia 2 loudspeakers, with a nominal impedance of 4 ohms that dips to 2.8 in the bass, demand less of an amplifier."
You had your doubts with this statement also Victor.
""the double basses that give extra urgency and dread to the symphony's opening were hardly audible through the JA200 Mk.IIs. While I can't confirm that this bass shyness was due to the Alexias' impedance dip down low"
Once we've seen the impedance in conjunction with the -phase angle graph in the test, only then we'll see the true EPDR (equivalent peak dissipation resistance) impedance in the bass as seen by the amp, and I will lay money on it, that's it's going to be lower than 2.8ohm
Cheers George
i had a pr of ja80s and later a da60 integrated, both sounded fine but the da60 was one of the most unreliable pieces of gear i ever owned.
hopefully the latest jadis are built to go the distance.
George, I would be willing to bet that your supposition that the Alexia’s drop below 2.8 ohms is going to be spot on!
IMO, utilizing the new Jadis 200 Mk2’s with this particular set-up was a recipe for failure from the beginning....too bad that a good amp is not getting the precise and accurate review that it deserves. Perhaps request a follow up with more appropriate ancillary gear...and another reviewer, lol.