Gryphon Audio Designs Antileon EVO Stereo Power Amplifier
- by Robert Harley
- Jun 28th, 2021
Audio components come and go over the years, but a few designs are so fundamentally correct from their inception that the product’s basic architecture cannot be improved upon. A prime example is the Antileon power amplifier from Gryphon Audio Systems of Denmark. Introduced in 1995, the amplifier is now in a third iteration—the Antileon EVO, reviewed here. Although it features upgraded parts and a few new design tweaks, the Antileon EVO’s fundamental DNA remains the same
That DNA is like a blueprint for creating a no-compromise stereo power amplifier: pure Class A operation, an absolutely unflappable power supply, an overkill output stage, and massive heatsinks. Add completely independent left and right channels (including transformers and power cords), very little negative feedback, balanced circuitry, fully discrete components throughout with no coupling capacitors, and lavish execution with spectacular metalwork and industrial design, and you have the foundation of an amplifier with potentially reference-class performance. All the basic design elements of the original Antileon are here in the EVO, but taken to the next level of execution.
The Antileon EVO is the very definition of a dreadnought—one look and you know that this amplifier means business. Although rated at 150Wpc into 8 ohms, the Antileon’s size, weight, and construction suggest an amplifier of five times that power output. But as we’ll see, such large hardware is required to ensure that the amplifier delivers its rated power in Class A operation.
Before delving into the Antileon EVO, a little history is in order. Gryphon Audio Systems was founded in 1985 by Flemming Rasmussen, in the same way that many of the best high-end companies started—with the founder building a one-off, no-compromise component for his own use. In Rasmussen’s case, he created a phono preamplifier so that he could better hear exactly how the various phono cartridges he distributed sounded. When a Japanese distributor heard this phono- stage in a CES demo, he immediately asked Rasmussen to build a second unit for him. Unbeknownst to Rasmussen, the distributor loaned the phonostage to Japan’s prestigious Stereo Sound magazine, which promptly awarded the Headamp, as it was called, its highest honor. Gryphon Audio Designs was in business.
Thirty-six years later, Gryphon is a major manufacturer of a full line of electronics, sources, loudspeakers, and cables. Yet the mindset with which the company was started—building components without commercial constraint—is still alive and well. Although not that renowned in North America, the marque is revered in Europe and Asia. My only previous experience with Gryphon (other than at shows) was an exceptional one. In 2012, I visited Andy Payor of Rockport Technologies to learn more about how he designs and builds speakers (see my review of Rockport’s Altair in Issue 214). In his spectacular custom listening room, Payor played for me his flagship Arakkis loudspeaker, actively tri-amped with all-Gryphon amplification. The sound was transcendent. I wrote a blog about that experience, titled “The Best Stereo System I’ve Ever Heard,” which is exactly what it was at that time. Andy Payor is among a small, very elite group of the world’s top speaker designers who scour the planet for the best-sounding amplification. That he would choose Gryphon to demonstrate his flagship speaks volumes.
The Antileon EVO makes quite a visual statement apart from its sheer muscular bulk. The front panel eschews the typical flat faceplate in favor of polished black-acrylic panels flanking a hemispherical ribbed column. The polished acrylic adds a touch of elegance. A large sub-panel, partially recessed into the acrylic side panels, contains a row of buttons and a display. The left-most button turns the amplifier on and off. Turning the amplifier on automatically launches an elaborate test routine that checks the amplifier’s operating conditions before full power-up. This procedure is accompanied by flashing red indicators in the subpanel. After a few seconds, the test indicators go dark and the amplifier is ready for action. You can also manually run the diagnostic program by pressing a front-panel button.
An interesting feature gives you the ability to select bias level—either low, medium, or high. The “low” setting is for listening at lower volumes, in smaller rooms, or to background music, where reducing the amplifier’s electrical consumption takes precedence over the last measure of sound quality. The “low” setting is also ideal for those with high-sensitivity loudspeakers. In the “low” position, the Antileon EVO operates in Class A up to 25Wpc before switching to Class A/B, and runs a little hotter than you’d expect from a big amp. The “mid” setting doubles the Class A output power to 50W before it switches to Class A/B. In the “high” setting, the EVO outputs its full rated power of 150Wpc in Class A. When operated in the high-bias mode, the EVO generates so much heat that you can’t touch the top casework for more than a second. But that’s the nature of Class A operation. Counterintuitively, the harder you drive a Class A amplifier, the cooler it runs, relatively speaking. (When amplifying high-level signals, more of the power is delivered to the speakers rather than dissipated as heat by the transistors and heatsinks.)
When connected to a Gryphon preamplifier, the EVO will automatically adjust its bias based on the preamp’s volume-control setting, a feature called “Green Bias.” Note that Green Bias is definitely not an attempt to track the signal level and continuously adjust the bias on the fly. These “sliding bias” systems, Gryphon contends, can’t respond quickly enough to keep the output stage in Class A at all times. (See the sidebar for a detailed explanation of Class A operation.)
Because the Antileon EVO is a true dual-mono design, right down to the separate left-channel and right-channel transformers, the amplifier has two 15A IEC sockets for two power cords. Inputs are balanced only, reflecting the fully balanced nature of the circuitry. The superlative binding posts are custom-made by Gryphon. A pair of handles on the rear panel is handy when hefting this 185-pound beast. The top panel is dominated by a massive circular transformer cover that has the Gryphon logo etched into it. The two transformers are stacked atop each other beneath the cover. Each of these transformers is rated at a whopping 1.5kVA, and they are mounted in an epoxy resin and then in a suspension system to isolate the amplifier’s circuits from any transformer vibration. The transformers feed filter banks of 335,000µF of capacitance per channel. In addition to the main filter bank, bypass caps are located next to the output transistors. This level of power supply is required to provide enough current for the 20 output transistors per channel to deliver 150Wpc continuously in Class A operation. A consequence of this massive supply, output stage, and heatsinks is the EVO’s ability to double its power rating as the impedance is halved, all the way down to one ohm, and to remain stable. When driving one ohm, the EVO is rated at 1200Wpc, if your wall outlet can supply that much current. Gryphon says that the amplifier is stable driving a half-ohm impedance. Clearly, the Antileon EVO will drive even the cruelest loudspeaker loads.
The EVO’s supply is larger than that found in the two previous generations of the Antileon. In addition to the increase in power-supply size over its predecessor, the EVO’s input stage is all new. The driver stage is independently regulated, and powered from its own transformer windings. Gryphon has developed a mechanical design that allows the driver stage to thermally track the output transistors for greater linearity. The circuit is balanced from input throughout the voltage amplifying stages, thus the lack of unbalanced RCA jacks. Internal wiring is minimal, and where it is used, the wiring is Gryphon’s Guideline Reference, a silver conductor embedded with gold. The connection from the output stage to binding posts is a massive busbar.
The metalwork and finish quality are absolutely first-rate. The closer you look, the more you appreciate the many small design touches that obviously added to the manufacturing cost, but that also add up to a striking visual statement. The Antileon EVO is priced at $39,000, and is available in a mono version with twice the output-current capabilities. It’s worth noting that the Antileon EVO is Gryphon’s second lowest-priced amplifier, with five models above it (counting stereo and mono versions). Gryphon’s lowest-priced amplifier is the Essence at $22,800, with 50Wpc Class A output.
Gryphon recently introduced a line of audio racks and amplifier stands, called StandArt. They sent to me the amplifier stand, which perfectly complements the amplifier’s look and also appears to be well-engineered for vibration isolation. The shelf is a constrained-layer-damped design with a top plate made from Kerrock, a type of engineered stone based on an acrylic resin. The stand is terminated with dual-layer Gryphon Black Spike points.
All things considered, the EVO is a lot of amplifier for the money.
Some audio experiences stick with you over the years, indelibly etched into memory. For me, one of those experiences is the first time I heard a Class A amplifier in my system—the Mark Levinson No.20.5 monoblock, back in 1991. A landmark design, the No.20.5 had an ease and liquidity that I hadn’t heard before from solid-state. As with other Mark Levinson products of the era, the No.20.5 was very laid back, with a subtle expressiveness. Other Class A amplifiers I’ve heard since also exhibited an understated character that favored a relaxed ease over an incisive and vivid presentation—a shrinking violet, if you will.
But the Gryphon Antileon EVO sounded nothing like what I expected. Rather than presenting a polite and self-effacing sound, the Antileon EVO’s character was one of bold assertiveness and visceral grip. Yes, the EVO had those delicious hallmarks of Class A—timbral liquidity, along with an absence of treble glare and grain—but at the same time the music was full of vibrant life, dynamism, and color.
The Antileon EVO’s defining character was one of organic, full-bodied warmth. Instruments and voices were rendered with a density and richness of tone color, along with a “roundness” that’s hard to describe. The EVO was the antithesis of the threadbare and bleached textures that are common shortcomings of solid-state amplifiers. The sound was warm and utterly liquid—almost voluptuous—yet without sounding thick, colored, or closed-in. With a somewhat midrange-forward presentation, the EVO was tube-like in the best sense, but the amplifier didn’t sound like tubes. Rather, the Antileon simply presented midrange and treble textures free of grain, and of the metallic patina that overlays timbres. One consequence of this character was a wonderful “human” quality to voices that emphasized body and warmth. I could hear more clearly the dark huskiness in Diana Krall’s voice on “Temptation” from The Girl in the Other Room. On the track “Cantaloop” from The Manhattan Transfer’s album The Junction, the four-part harmonies sounded richer and denser, at once better blended, yet with each voice more distinct. Without that bit of excessive whiteness in the top end, the soprano part was better integrated with the other voices. On Constantine Catena’s solo piano performances of works by Debussy and Schumann [Fazioli F278], the instrument had a huge, authoritative, and commanding quality on the big left-hand chords, lighting up the surrounding acoustic. This recording was also notable for its lack of hardness, glare, and “skeletal” sound on upper-register transient attacks.
The EVO’s gorgeous liquidity was also readily apparent on Act Your Age, from Gordon Goodwin’s Big Phat Band. The big brass and woodwind section were smooth without being syrupy, and the exuberant trumpets on “Back Row Politics” were lifelike in their freedom from glassy glare. This high-octane album really highlighted my earlier comment about the EVO sounding energetic, upbeat, authoritative, and exciting. Conte Condoli’s flugelhorn on one of my own recordings (Confirmation by the Chiz Harris Quartet) had a rich, golden, burnished character. Some components emphasize the upper harmonics, making the instrument sound like a cross between a flugelhorn and a trumpet. Not the Antileon EVO. Despite the smooth and liquid treble, the EVO had a good measure of resolution and top-octave air. This amplifier isn’t a “detail freak,” but rather one that strikes a wonderful balance between resolution and ease. The EVO encourages higher playback levels and longer listening sessions, due to the absence of listener fatigue.
One of Class A’s great virtues is that its harmonic distortion spectrum is primarily second and third harmonic, with virtually no odd-order upper harmonics, such as sevenths and ninths. We hear those upper-harmonic distortion components as harshness. Second-harmonic distortion, however, is relatively benign since it occurs in nature, and is a significant component of instrumental overtones. In fact, some studio-processing devices intentionally add a bit of second-harmonic to make an instrument sound warmer and “fatter.” By contrast, seventh and nineth harmonics are rarely heard in nature, and add a hard, steely character to the sound. Not coincidentally, these upper-order harmonics are produced when metal is struck—not a pleasant sound, or one you want overlaying harmonic textures. A distortion spectrum that’s primarily second and third harmonic, without the upper-order harmonics, confers the warmth and liquidity that are hallmarks of Class A designs.
The EVO exerted an iron-fisted grip on the Wilson Chronosonic’s big woofers, delivering a “center-of-the-earth” solidity and impact. (Note that my auditioning was without the Wilson SubSonic subwoofers engaged.) The amp was unflappable at any listening level, even with the most demanding music. When reproduced by an amplifier running out of power, kickdrum can start to sound flabby, but I heard no such compromise from the EVO in the bottom octaves. It even reproduced with considerably authority the pedal tones on the spectacular The Bach Gamut, a live program of solo organ performed by Virgil Fox and recorded by Keith Johnson. A little higher up, in the midbass, the EVO was warm and full—perhaps even a bit generous. But unlike some amplifiers that sacrifice precise articulation for weight, the EVO had tremendous dynamic and textural resolution along with powerful muscularity. Electric bass had a wonderful “purring” quality, and acoustic bass sounded like what it is—a big wooden body resonating. The Antileon EVO revealed, in exquisite detail, the subtleties of great bass players. The combination of dynamic agility, pitch definition, fullness, and powerful rhythmic drive was thrilling.
While working on this review, I learned of the passing of one of my favorite musicians, someone I’d been following since my early 20s—Chick Corea. (A 40″ x 50″ portrait of him hangs in my listening room.) I spent a day revisiting his vast and incredibly varied body of work, much of it featuring virtuoso bass players (Miroslav Vituoš, Stanley Clarke, Eddie Gomez, Dave Holland, John Pattitucci, Christian McBride, etc.). The Antileon EVO beautifully conveyed Vituoš’ inventive phrasing on Now He Sings, Now He Sobs, Gomez’s hard-driving style on “The One Step” from the album Friends, McBride’s stunning virtuosity on the recent live album Trilogy 2. The Antileon EVO was a perfect vehicle for appreciating Corea’s music, and the outstanding bass playing on all his albums.
Although I’ve characterized the Antileon EVO as leaning toward a warm and rich sound, it was also upbeat and exciting—often mutually exclusive qualities. I think that the viscerally engaging aspect of the amplifier is due to its tremendous density of instrumental color, as well its stunning speed and dynamic impact. This rich instrumental color is the result of the generous warmth in the power range coupled with the absence of the thin, dry, sterile treble sound of much solid-state. The upbeat quality is driven by the EVO’s transient speed and power. This is a very fast amplifier that can swing dynamic contrasts with startling impact, and real weight behind that impact. The snare pop on Steely Dan’s Two Against Nature—one of the best drum sounds I know of on disc—was phenomenal in its explosive energy, adding a visceral feeling of propulsion to the music. In fact, I can’t say that I’ve heard an amplifier with more startling dynamics than the Antileon EVO.
Some potential purchasers may view the EVO’s 150Wpc power output as inadequate, particularly in an amplifier that costs $39,000. But I can tell you that not all watts are created equal. Not only are the EVO’s 150 watts Class A watts, but the amplifier also has the ability to double its output power as the impedance is halved, all the way to one ohm, where it can deliver 1200Wpc. That’s a sign that the amplifier can deliver ample current. Driving the Wilson Chronosonic XVX, the EVO showed no signs of strain, or of approaching its power-output limit, on even the most dynamic and demanding material.
A more legitimate caveat is the Antileon EVO’s power consumption and heat output. The amplifier was in my system in the winter months, including February’s deep freeze, so I didn’t mind the heat it generated. That may be different in the summer, or in hot climates. The EVO’s massive inefficiency and power draw should also be considered. I get 100% of my electricity from rooftop solar, and so was not concerned about the EVO’s environmental impact and power cost. You should weigh these factors when choosing an amplifier. I appreciated, however, the ability to lower the bias with the front-panel buttons, greatly reducing the energy consumption and heat output.
Class A amplifiers are sometimes characterized as smooth and sweet, yet lacking treble openness, dynamic impact, and excitement. The Gryphon Antileon EVO’s triumph is delivering the great virtues of Class A operation—seductive warmth, liquid textures, and a sense of ease—but with tremendous speed and dynamic authority along with a visceral excitement and energy. Its warm harmonic richness and absence of grain and glare reveal the beauty of tone colors in a way that is nothing short of seductive.
Throw in stunning build-quality and striking industrial design, and you have an amplifier that pushes all the right buttons. Having lived with this third-generation Antileon, it’s easy to see why its fundamental architecture has endured for 26 years—and counting.
Tags: GRYPHON POWER AMPLIFIER
By Robert Harley
My older brother Stephen introduced me to music when I was about 12 years old. Stephen was a prodigious musical talent (he went on to get a degree in Composition) who generously shared his records and passion for music with his little brother.More articles from this editor
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