General Asylum: REVIEW: Joule Electra Stargate Amplifier (Tube) by Celluloid General audio topics that don't fit into specific categories.

For Sale Ads FAQ / News / Events

Model:	Stargate
Category:	Amplifier (Tube)
Suggested Retail Price:	$5500
Description:	30 watts SET
Manufacturer URL:	Joule Electra
Model Picture:	View

Review by Celluloid on November 11, 2001 at 06:22:09 IP Address: 168.122.12.61

Add Your Review for the Stargate

---

JOULE ELECTRA STARGATE

BACKGROUND: As an owner of many tube amplifiers over the years, I have sampled a wide range of the available flavors...from straight push-pull, push-pull triode, adjustable feedback models to SETs of various sizes. Among my purchases have been the M100 Audio Research, various Conrad Johnsons, the Music Reference 9, Lux tubed mono blocks, vintage Scott and Stromberg-Carlsons, EARs, the original Dynacos, McIntosh monos, the 8417 & KT 88 Quicksilvers, the Bel Canto 40i, the Mesa Baron and others. And that’s not counting all the solid states, which I have rarely kept very long in my main system. Hey, you only live once (I think) so I figure if I average one or two tube amps per year sooner or later I may get lucky before I simply run out of time. Not that some of these weren’t very good, even excellent, but many of the designs were deficient in either dynamic power or range, bass and/or top end, or reliability. Admittedly, a number of my speaker choices had difficult impedance curves or were simply too inefficient to be seriously driven by tubes. One of the companies that always intrigued me was Joule Electra, especially since their OTL show demonstrations with the Merlins have been so impressive. His Joule Linestage is justifiably famous--and Jud is well-known for creating innovative designs with NOS tubes. When I heard Jud Barber was designing a new transformer-based amplifier, the Stargate, utilizing the same 6C33B used in BAT and Lamm, I decided to take the plunge--without an audition. A Joule dealer I know had one pair on the floor and raved about them, but his shop was nearly 2000 miles away. I also talked to both Bobby Palkovic at Merlin and Jud a number of times before deciding to become something of a guinea pig--they were not only a brand new design, but I would be among the first owners.

THE EQUIPMENT: These large, hefty tube SET mono block amplifiers come packed individually in impressively sturdy plastic cases. This is the best packing job on amplifiers I’ve ever seen--the kind of cases manufacturers use themselves for their CES demos. My Fedex delivery man dropped them off personally after duty hours--he packed them to my house in his own car, not in his uniform and company truck. Why? He said he wanted to see my latest audio purchase; he’s gotten fascinated with the whole hobby after a dozen audio deliveries to my house. So we unpacked them together and both of us shook our heads and smiled. They’re big and shiny. The chassis is certainly larger than it appears in pictures. I may be grinning but my wife sighs. There goes the living room. I’ve already taken over another large room with a dedicated widescreen 5 channel video rig. Hey honey, you love music, right?? I actually bought these just for you...these are your Christmas present! (Pretty suave, huh? Well, it helps to be experienced at these post-purchase negotiations on the home front.) If they do go into a living room, be careful, the supplied spikes can put a half-inch hole in your hardwood floors. I understand that Jud Barber, the chief designer/owner of Joule Electra now supplies acrylic disks to protect your flooring (and if he reads this, I hope he sends me a set...hint.) I did my early listening with the spikes, but later, after my wife got a look at what was happening to her antique floors, I decided discretion was the better part of valor and rested the amps on some adhesive felt pads. There are two large Russian 6C33B (MIG) output tubes per side, putting out 30 watts parallel SET. (You can also purchase in triode, Class A, push-pull.) I listened to both modes in the last 11 months. There is a handy knob on the back that allows one to adjust the feedback, though even a full 360 turn only adds 3db of negative feedback, but still, the damping of frequency extremes is quite noticeable--especially in the bass response. Input and output tubes have bias controls, with an LED readout on the top plate of the amp. Mine came in champagne-colored fascia and transformer covers, which mitigates the straightforward industrial look of the mono blocks. Happily, the actual word “Stargate”--a little too trekkie for my taste--appears nowhere on the amplifier.

THE SOUND: First impressions? What one notices initially upon firing up the amps are the frequency extension, the sense of power/control and the image size. Quick conclusion? Sounds like the best attributes of tube and solid state have finally been combined. The first months of listening are devoted to resetting your ears and expectations. That’s because the increase in detail is quite stunning; you begin to wonder where these inner nuances of the music have been hiding. Could this be the SET magic that devotees are always talking about? Perhaps it’s the newest edition of the Merlins? Or just brilliant and lucky system synergy. My last rig, happily keeping the beat in a fellow AA inmate’s home, was hardly deficient in this area (tube and ss amps driving the Guarneris.) But this is a quantum leap in both macro and micro dynamics. Since these “new” subtle details often emerge from the background, albeit quite clearly and distinctly, one senses a far greater depth and width to the sound stage. After a couple of months re-listening to all your favorite CDs just to illuminate these previously buried treasures, the larger musical picture comes into focus.

These are fast and articulate amplifiers: by that I mean these brutes keep time--with a vengeance. If you wonder what “pace and timing” is, or why the British reviewers rave about “PRAT, these amps will vividly define these values for you and settle all questions. I’ve never quite experienced (especially in its no feedback mode) amps like this that jumps all over “the beat” And pace, timing, and transient speed spells resolution--meaning the individuality of the each musical performance prevails. This would make you think that they are lean, and, well they are up to a point, but, paradoxically, they are also very rich harmonically. An audio high wire act. They dance right down that fine line, refusing to be ruffled by preconceived notions that separate resolution from richness. This complements my own tastes perfectly. For those who have read my previous reviews, you know my particular audio hobgoblin is any component that leads to a homogenization of the music. For example, the Holograms (an Acoustic Zen “tuned” biwire speaker cable--see my review) lend a very slight, pleasant--i.e. forgiving--extra body to the music. This can be interesting or attractive, for a while. But after inserting pure silver speaker cables (B&Ws) everything--especially the resolving of dynamics, “air” and ambiance improved so greatly that the Holograms made a quick exit from the system. They were dampening the resolving attributes of the Joules. Holograms can provide an extra smoothening or filtering of the edges of the music, and I can understand why one might (un)consciously choose to go this route. But the Joules don’t need it, you need something much more neutral to get the best out of them. This is exactly where the Joules surpass many other amplifiers by a wide margin, with a twist. While everything is purer and more distinct, there is also a sense of greater musicality, even on deficient recordings. Not really a paradox, but usually, highly resolving amplifiers come at a cost, since too much “transparency” renders inferior recordings unlistenable. With the Joules, even average recordings tend to sound unusually satisfying. (Especially if you get the polarity right...see below.)

To check my perceptions of their astonishing retrieval of micro-dynamics against a known reference, I used the Chesky test cd and followed a Stereophile reviewer’s standard of comparison, track 3 at 2:08 for low level resolution. One assumes the reviewer chose this selection because it is difficult to hear the percussion at that point in the track. You will wonder what he is talking about with the Joules. Huh? There isn’t anything special to discern here--I would have never used this myself for true challenge, since all is as clear and distinct as one could imagine. Apparently, since I am only guessing at the reviewer’s assumptions, some amplifiers can’t reproduce this percussion properly, but on the Joules you can hear it with absolute clarity, coming up effortlessly from the background. I think a fair question one might ask about amplifiers that can reproduce these micro-dynamics so easily is whether or not these details become too forward, thus destroying the back to front sound stage. We’ve all heard amplifiers, especially solid-staters, that are outstanding at retrieving details, but sound too aggressive. If these lower level signals move up from the rear to take residence at plane of the baffle, “deep” space would then be restricted to an area from the face of the speaker to the listener-- which is my definition of an “etched” and hard sound. The Stargates disprove the common audiophile notion that components which excel at resolution do so at the expense of depth of field and warmth.

A better example of a real world test is how the Stargates handle Sinatra’s “Live at the Sands,” a decidely non-audiophile recording that can easily humble a system. Through the Joules it is absolutely thrilling. Basie swings huge dynamics, with a horn section can knock you off your pins, and with the 50 year old “voice” in vintage form. I formerly had many reservations of this recording on compact disc. The Stargates reveal a Sinatra who is little ragged and coarse in the few first numbers (the show seems to be recorded in continuity) but he grows increasingly warm, resonant and powerful as the performance develops. Everything is revealed, including breathing techniques, vocal moves with the mike, and all the ambient venue cues and placement of the instruments. For instance, I’ve never noticed before how Frank clearly uses an “ffff” sound in the mike after singing the word“love”at the end of a phrase. This sustained “f”is completely distinct from the “v” and enters only after the full word is sung. It’s a little grace note, and isn’t overemphasized, but it adds immeasurably to the listener’s perception of the humanity of the performer and the intimacy and drama of the event. With the Guarneris and CJ, it was a lesser experience. The Stargates/Merlins seem more refined, balanced and extended, with far better resolution. They give you the not only the resonance of the chest cavity, but also the “throat” and breathing techniques of Sinatra. This is all unambiguously integrated with the “sound” of the microphone and the ambient space of the “room,” providing and unexpectedly rich, warm yet intimate experience. Magic! You feel transported back in time and space. You become intellectually engaged, i.e. aware of the equipment/music interface, but the emotional content quickly subsumes the intellect and one is completely immersed in the musical event to the exclusion of all other considerations.

As for the bottom end of the amp, the Stargates are unusual for tubes in how deep and authoritative they sound. In my room, I can get a very full, precise tone at 31.5 hz--nothing tubby or flabby and no with no hangover and amazingly quick recovery in complex or congested passages (at least on the Merlins.) Playing test tones shows an admirably linear response, despite my very difficult room. This could be due to the size of the output transformer, which alone weighs over 20 pounds. I can easily rattle the picture frames and mirrors in the listening room on cds like “Spyboy,”(another Stereophile reviewer favorite) with torture tracks like “The Maker” or “Deeper Well” before distress. To see how loudly it might play, I tried adjusting the Linestage for double the gain, but didn’t attain any additional headroom. The solid foundation and grip makes it seem that there is tremendous power in reserve, but there really isn’t. Earthshaking volume settings (and I like to play loud; but others tell me it’s more like “very, very loud”) can drive any tube amp into distress, and in this regard the Joules let you know if it is pushed too hard. It is only 30 watts, after all, and how much is 30 watts SET? I substituted a well-respected Plinius integrated into the system for comparison, but it really wasn’t a fair fight. The Joule system simply sounded superior. In solid state there is a demonstrable reduction in image size and depth, with less dynamic attack and contrast. It was as the dimension and color was removed. The comparison did, interestingly, reminded me how much (on the Joules) I had gotten into the habit of riding the volume control. That is, even on familiar recordings I had the sense that I was consistently turning down the volume a minute or two into a track because I had underestimated the dynamic range of a recording. The Joules have startling dynamic contrasts. As for the rated power and compatability, you can usually throw the book out with SETS. This pair drove both Quad and Martin Logan CLS with aplomb and had plenty of horsepower left in reserve. In fact, they sounded subjective bigger (bolder and better) than my friend’s 100 watt ARCs driving the MLs. And he thought so too. Ultimately, the Stargates seem to be a very modern style of tube amplifier. . .

LISTENING NOTES: You must play around with the polarity, especially at your speakers. I know the Joule LS ships with polarity reversed in order to cut down on the extra wiring, stages, etc. Clark Johnsen’s study of rarefaction, “The Wood Effect” should be required reading for all audiophiles. The effect is not subtle. It can transform a system when one gets it right; and even using test cds with polarity tracks is not enough, I have found. Trust your ears and your favorite cds. If you have a polarity switch in the digital processor, like Meridian’s, you may find that has a small additional benefit, though not so great as swapping speaker polarity. I always get the speaker leads right with the cd first, then go back and forth on the much more subtle digital end. The more obvious sounding the extremes in polarity shift in any single component, the better the design, if I read Clark’s thesis correctly. And the polarity difference in all the Joule equipment I’ve used really is dramatic. And, of course it follows that it also reveals polarity in recordings with great ease. For those who don’t think rarefaction is audible, especially on cds, I guarantee you will hear it on Joule. I mention this because the Stereophile reviewer who uses “Spyboy” and waxes at length about the vocals and bass has never suggested that this cd is clearly recorded and/or pressed in mixed polarity. If he has the vocals firmly anchored in the middle, I can guarantee you that the bass and drums are wrong! And if he is really hearing subterranean bass, the voice has to significantly diffuse. No matter which polarity you choose, it is “wrong”--as the Joule tells you emphatically. Unfortunately, a test cd typically gives one a single instrument/voice. The Chesky test cd gives one a trumpet. Not helpful. You really need a strong powerful bottom end and a vocalist/piano, and no matter what polarity you chose, you will still find many cds with mixed or reversed polarity.

There is a feedback knob at the back of each amplifier which can reduce the transient speed and assuage the edge of the worst recordings. As I understand it, it doesn’t affect the frequency response at all, but instead alters the speed of the transient response. As you turn it counterclockwise, the sound softens considerably, giving you the more typical tube sound at the point where you’ve added the full 3 db of negative feedback. I generally prefer no feedback, but I understand others are using the knobs as a tone control, dialing in just the right amount for each cd. A very handy tool.

TECH NOTES: After owning temperamental tube gear (I got to know ARC and CJ tech people pretty well!) the Stargates are apparently bulletproof. I blew one of the big output tubes in the first weeks, (Jud ships with an extra 6C33B just in case,) and instead of taking down the amp in flames (Hello CJ, it’s me again!) it didn’t even cause a hiccup or fuse replacement. I understand there is a huge NOS stock of these tubes in inventory, plus they are very cheap as these things go. (All the other original tubes are running pretty close to the original bias settings despite vigorous play of nearly a year.) It’s difficult to get a fix on where this sense of dynamic power comes from since the Joule LS 100 has such modest published specifications for gain. Mine is set at a miserly 4db of total gain (!) but adding two jumpers to the board doubles that number. With the Joule LS and Stargates I can rarely exceed 12 o’clock on the volume before it is just too much. (In fact, the extremes of my listening range runs only from about 10 to 1 on the volume pot. I could probably use another halving of the overall gain in the pre amp, anyway to do this, Jud?

As for other tips, a solidly engineered power cord seems to add a slight reduction of power line noise, but otherwise, I didn’t have to go esoteric with tweaks. I tried a few of the high end PCs in the $300 range and a couple seemed to actually mess up the image and bass. One or two were indistinguishable from my own Asylum re-terminated Belden. I eventually settled on the Bolder Cable type 1--it sounds both quiet and unobtrusive.

CONCLUSIONS: Jud Barber is renowned for his OTL designs and he voiced the Stargates to sound as close as possible to these expensive OTL mono blocks, but with the advantages that a transformer can give when properly implemented. He seems to have gotten it just right. The Stargates put out a rich and dramatic sound that has remarkable resolution and authority of presentation. On well-recorded CDs it was about the best I’ve auditioned and on those middling recordings, you might be surprised how these amplifiers can make them sing.

---

Product Weakness:	might need careful matching with inefficient speakers
Product Strengths:	clear, clean, articulate--with both resolution and warmth

---

Associated Equipment for this Review:
Amplifier:	Joule Electra Stargate
Preamplifier (or None if Integrated):	Joule Electra LS 100 (Purist option)
Sources (CDP/Turntable):	Marantz SACD1, Meridian 508.24
Speakers:	Merlin Millenium/Battery BAM
Cables/Interconnects:	Luminus Audio Synchestra Signature ICs, Bolder 1 PCs, B&W Silver Anniversary silver biwire
Music Used (Genre/Selections):	Jazz, vocals, rock
Room Size (LxWxH):	15 x 24 x 7.5
Room Comments/Treatments:	Miracle Audio Timbers (ebony)
Time Period/Length of Audition:	11 months
Other (Power Conditioner etc.):	ESP Power distributor, Acme outlet
Type of Audition/Review:	Product Owner
Your System (if other than home audition):	N/A

---

This post is made possible by the generous support of people like you and our sponsors:

Kimber Kable

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---