Jadis Defy 7, Quicksilver KT88, VAC PA90 tubed power amplifiers

"It's the difference between a stuffed dog and the real thing," said Gunter (George) Bischoff, of Melos Audio, on the difference between solid-state gear and tubes. "The real dog may piss on the rug, needs visits to the vet, gets fleas, has to be walked, but it's a living thing—a real dog. The stuffed dog requires no care, needs no maintenance, but has no life."

"But I own a cat, George. Low maintenance."

"You still own a live cat, not a stuffed cat. The cat needs to be fed, has to get rabies shots. There is still some maintenance."

I gotta be a glutton for punishment.

A year or so ago, I received a pair of VTL 225 monos on loan from Audio Advisor, Inc.—David Manley's 225Wpc monoblock tube amps, the ones so hailed by Robert Harley.

All was well for a month or so—but this was summertime. Whew—those sixteen EL34 output tubes (eight output tubes per amp) gave off a lot of heat. I had the amps atop a record cabinet in front of some windows. You could see great gobs of heat rise from the amps.

The sound? Splendid on my Spendor S100 speakers. Maybe slightly rolled-off on top—with ample, if not particularly tight bass. The amps had a lot of power, but what I missed was bass solidity. Still, I enjoyed these amps—until the fateful moment when Götterdämmerung took place.

I looked up from my listening chair and one of the EL34s began to glow a deep orange, as if the tube were aflame! Simultaneously, I heard distortion. I leaped up to turn off the amp, but too late. The tube went from orange to white before I could hit the off switch.

Whew—at least the amp didn't catch fire or damage my speakers. I returned both loaner amps to Audio Advisor and turned my attention to solid-state—the B&K M-200 monos and the Adcom GFA-565 monoblocks I've already written about. (Audio Advisor says all they did was replace a couple EL34s and the amp was fine. Still, I shudder to think of what might have happened if I'd gone out for the newspapers while the amps were warming up.)

What is it about the sound of tubes?
Whenever I have solid-state gear, I keep longing for the sound of tubes. I'm reminded of what a certain manufacturer of solid-state preamps once said—that he couldn't design a solid-state amp that sounded like tubes. He'd tried. Tubes and transistors would always sound different, he feared—despairing, perhaps, of his own ability to clone the sound of tubes.

Funny, ain't it, how solid-state manufacturers are always trying to clone the sound of tubes. "It's his most tubelike amp yet," is a comment you sometimes hear from audiophiles whenever a new solid-state amp by a top designer hits the market. But then a couple of years passes and this designer's next amp is the most tubelike ever.

We talk about how amps with MOSFET output devices sound more "tubelike" than amps with bipolar output transistors. But tubelike isn't the same as tube. Tube gear tends to produce timbres which sound different from solid-state gear. Tube gear tends to sound more "musical." For those of us who grew up with the sound of tubes—in table radios, early TV sets, and ordinary phonographs—there is a rightness about the sound of tubes. I remember our family's old Westinghouse floorstanding console radio—wonderful rich sound, although I'm sure the highs were scarce. ("The radio has a nice tone," said my mom. And she was right.)

So, hankering for that old-time sound, I periodically get sick of solid-state and give tubes another try. For instance, I tried a couple of Quicksilver amps with the Spendor S100s—both the "standard" Quicksilver monos with the 8417 output tubes, and the KT88 version, with the KT88s. Nice sound—truthful timbres, holographic soundstage and all that—but not enough dynamic force in the bass (I was going to say "balls," but...). Neither pair of Quicksilver amps exploded. This has always been a good quality about Quickies—excellent reliability.

The Jadis Defy 7
Howie Hyperfy is big on Jadis (footnote 1).

He had the JA-80s, then the JA-200s—neither of which, unfortunately, could coax what he (or I) felt was convincing bass from his Avalon Eclipses.


"Howie is still in hi-fi hell, tearing his hair out," said Wolf Man, with his wolfish smile.

At Victor Goldstein's suggestion—the Jadis importer—Howie tried a Defy 7 (footnote 2). (Howie is in the hi-fi business, so this was easy. Actually, Howie is a consultant to Jadis. And a good one, too.)

So Howie got the Defy 7, which I would agree does have more bass impact (I was going to say "balls" again, but I caught myself), and he STILL wasn't happy. In desperation, he called in Lars!!!!

"How was the sound, Lars?" I asked my Swedish buddy.

"Good detail and transparency. But the bass I'm afraid was lacking."


I haven't been to the Howie home lately, but I did phone Hyperfy to find out how the Defy 7s were getting along.

"Oh, great, great, great," enthused Hyperfy. "Tons of bass. Bass all over the place. You wouldn't believe the bass."

He was starting to sound a little like Victor.

"Lars didn't think so."

"Lars was a big help with speaker positioning. But I've done other things since his visit—Tube Traps in the corners, an absorbent panel on the back wall. Took care of the problem—that and the Defy 7s. Tons of bass," Howie refrained.

It sounded to me like he was trying to talk himself into hearing more bass.

Meanwhile, thanks to Victor Goldstein, I got a Jadis Defy 7. I still had the Spendor S100 speakers when the amp arrived—it took two people to carry it into my listening room. Big, big chassis. I didn't have to wait for good sound. Perhaps the amp had already had a few hours' use—it sounded as if it were already broken in.

I liked the amp, right off. Specifically, this $5495 stereo amp—which runs class-AB, by the way—sounds French. If you've heard a good French symphony orchestra, you'll know what I mean. The sound tends to be lean, crisp, clean—not at all fat or beefy, like, say, a German orchestra, or chocolatey, like the Vienna Philharmonic. I'm not saying there's anything wrong with the Vienna Philharmonic—I wouldn't want to hear a bunch of Frenchmen play Bruckner, for instance. But French orchestras have a distinctive sound, and the Jadis Defy 7 reminds me of it.

Bass, I thought, was very, very good for a tube amp—on my Spendor S100s, which can sound flabby with the wrong amp, especially the wrong tube amp. By this, I mean the bass was solid—less ample than it was with the VTL 225s, but tighter, better damped. As the week went by, the sound of the amp overall was very much to my liking—lean, clean, but also sweet, smooth. All this plus bass with a tight tushy. (Ooops! Sorry, ladies.)

Then it happened—exactly eight days after I first got the amp. It was a Sunday and the amp had been playing for at least 12 hours. I heard something which sounded like tube farting—coughing—in the right channel. "Damn," I said to myself, "I got a tube problem." Then I thought the problem stopped.

A few minutes later, the noise started again—only worse. And then—a pop, distortion (not necessarily in that order), and bluish-gray smoke. Fortunately, I was able to leap from my listening chair and turn it off. No damage to my speaker.

Victor Goldstein, the Jadis importer, was mortified.

Footnote 1: Jadis, Villedubert, France. Web: www.jadis-electronics.com. US Distributor: Fanfare International, Inc., New York, NY 10021 (1991); Bluebird Music Limited, 310 Rosewell Avenue, Toronto, Ontario M4R 2B2, Canada. Tel: (416) 638-8207. Fax: (416) 638-8115. Web: www.bluebirdmusic.com

Footnote 2: Martin Colloms reviewed the Jadis Defy 7 Mk.II in April 1993.—Ed.


teched58's picture

Anyone home? Has everyone over at Stereophile quit? AP has new stuff all the time. It's not of much interest since it's all record reviews, but at least they're trying.

Every time you rerun one of these old pieces, it only goes to emphasize how good you were then, as compared to what you are now.

JRT's picture

... and are interesting content regardless.

John Atkinson's picture
JRT wrote:
... and are interesting content regardless.

The page-view statistics do indicate that readers are interested in these vintage reviews.

John Atkinson
Technical Editor, Stereophile

Jack L's picture


Really ? YOU want to enlighten us how bad the Sterophile "new content" is "now" compared to 'those-were-the-days' "old pieces" ??

I am all ears !

Jack L

teched58's picture

...since you asked, one notable difference is that "now" YOU are Stereophile's single most prolific commenter.

Listening but not believing your ears!

Jack L's picture


"Prolific" defines:fruitful, abundant inventiveness or productivity.

W. Amadeus Mozart, for instant, was likely the "most prolific" classical music composer ever: 800 symphonies, concertos, chambers, opoeras & chorals despite his short 35-year lifespan !

If you have a problem with my being "Stereophile's single most prolfic commenter" here, why not voice your opinion to the editor here ?

Yes, I comment a lot on audio matters in Stereophile forums but I never ever attack its editorial review policy unlike YOU just did out of the blue !!!! Hence my above question to you !

Let me quote "www.the wildest.com":-
"the scariest & most dangerous DOG fights are the SILENT ones..."

I may comment a lot but the last action I would take is to attack the editorial policy of a publisher. Take it or leave it, pal!

Listening is believing

Jack L

Herb Reichert's picture

The Man

and the first guy I used to read


Jack L's picture


Bingo! Tubes give lifelike music, closest to live !

Listening to tubes is believing

Jack L

Jack L's picture


Not all tubes sound same. RCA sounds soo much better than Raytheon & Signet, for example, for the same tube models !!!

Also how does your "tubelike" sound like??

Frankly, I hate old tube sound: sluggish, & opague. I want my tube amps sound fast, punchy & see-thru transparent like the best solid-state amps, yet melodic & emotional without the clinicality of typical solidstate devices.

So lifelike sound for me, not any "tubelike" sound.

Listening is believing

Jack L

Jack L's picture


Not many tube amps in the current audio marketplace would act like "pissing dogs" some 30 years back ! Tube amps get better & more durable with time.

Yes, vinatage tube amps can be upgraded to get much much better sound with minimum or zip maintenance like a "stuffed dog".

The Dynaco PAS-2 phone-preamp & ST-70 power amp, which were donated to me free some 17 years back, sounded sluggish, opauge & noisy - totally unacceptble to my ears. I would have returned them to my donor friend right the way if I were not an electronic handyman.

That said, all the tubes inside the amps still worked OK!! No "pissing dog phenomemon" !

With my thorough upgrade, now the vintage Dynaco pairs sound fast, punchy & crystalline transparent. Acceptable to my ears !

What make the most substantial sonic improvement is the conversion of the EL34 UL output power stage of the power amp into triode/UL switcheable mode using a unique trioding topology that no commercial brandname power amps ever used, IMO. Much more complex than the historic traditional basic trioding topology used by nearly all brandname power amp makers since day one !

Unlike what Sam Telling commnented above, my Dynaco power amp sounds sooo much better in its trioded mode than its UL mode. Better design/built better sound !!

So "carefree real dog phenomenon" for all the tube amps I design/built/upgraded. Thank goodness !

Listening to tubes is believing

Jack L

jond's picture

It's great to see older articles especially Sam Tellig! And a bonus for me I started reading Stereophile in 1997 so this is a column I never read before. Thanks Stereophile more Sam Tellig and more J10 too.