Gryphon Apex Stereo power amplifier

Some time ago, an amplifier in for review caught fire when first powered up. I don't mean it smoked and sizzled and shut down—I mean that actual flames shot through the top grate. Fortunately, I was able to grab a kitchen fire extinguisher and douse the thing with foam. (Sorry, this was decades ago, and I don't remember the brand, but I think the company had a fire sale and was shut down.)

Another time, a representative of an amplifier manufacturer visited for an install. Once everything was connected and ready to be powered up, he assumed an unusually defensive stance. He turned his back to the amplifier, reached behind it, and, with a grimace on his face and eyeing the exit, flipped the power rocker on. Nothing exploded, and the amplifier powered up, but it was not a confidence-inspiring performance.

A "massive" upgrade
With those late '80s experiences in mind, I watched the Gryphon Apex Stereo, a manatee of an amplifier at 445lb, as it was tipped on its side so that it could pass through the door and be rolled on a dolly into my listening room. The pair of linebacker-sized piano movers entrusted with the task skillfully, carefully positioned the Gryphon in the designated space between my reference monoblocks then deftly righted it, landing it gently on its feet without raising a speck of dust from the old carpet. Whatever their fee, it was worth it!

Packaging a nearly 500lb behemoth for safe shipping and easy unpacking is an engineering challenge of its own. It took a great deal of ingenuity to implement packaging for the Apex that satisfies both criteria. It makes clever use of slippery sliding sheets—the kind used in hospitals to move patients—to slide the amp off its shipping pallet, and it includes an inflatable air wedge (specifically, a Winbag, footnote 1) to raise the amp, once off the pallet, one side at a time to remove the shock-absorbing shipping feet and, optionally, install the supplied spiked feet.

If you saw the Gryphon Apex Stereo amp on static display at AXPONA and noted how big it seemed in that large space, imagine how big it appears in my modest-sized listening room. It is nearly 3' deep, intimidating in its monolithic black oneness. It commands attention with a black hole pull.

The Gryphon Apex replaced a pair of darTZeel monoblocks in my system. Everything else remained the same, including the darTZeel NHB-18NS preamplifier. I carefully connected the amp to the speakers and to the preamp's balanced outputs and plugged the two AC cables into dedicated 20A lines. (I don't think this review would be possible if the electrical system of my house had not been upgraded a few months ago.) Once I was certain that all connections were correct, I flipped the two rear-panel power switches then tapped the red Standby icon on the touchscreen, bringing the Apex to life.


Red error lights flashing across the top of the touchscreen evoked flaming amplifiers in my mind and got my adrenaline flowing. Temperature Error, DC/HF Error, AC Phase—it looked like a massive failure through high temperatures and catastrophic input current. Had I crossed the speaker wires?

Thirty seconds of panic evaporated with the click of a relay, which extinguished the error lights and put the amp into Play mode. This was all completely normal. Whew!

You could admonish me for not reading the manual first. I did so later and learned that "all display indications will flash for approximately 25 seconds before the amplifier is fully operational." The Gryphon Apex will always be installed by a dealer, but I think it would be a good idea to provide a heads-up warning about those flashing error lights early in the manual and not wait until page 21. (Not that it would have helped me, since, when it happened, I had not cracked the manual at all.)

That is the last negative comment you'll read in this review about the Gryphon Apex Stereo amplifier.

Design and features
The Gryphon Apex Stereo and the sibling Apex Mono amplifiers (which were not auditioned here) are both powerful, cost-no-object designs. Both are biased heavily into class-A, meaning that the transistors never turn off, from the largest positive voltage through the maximum negative voltage. It's an inefficient way to bias transistors, but in addition to producing high electricity bills and a lot of heat, class-A bias also results in very low distortion and ear-pleasing sonics.

Gryphon says it distrusts autobiasing schemes that claim to dynamically adapt bias to changing conditions to optimize performance, believing such schemes have more to do with marketing than with technology. Gryphon admits that class-A entails heavy transformers, very large heatsinks, and large quantities of expensive metal and parts.

The inherent inefficiency of a class-A amplifier means that the Apex Stereo's massive dual-mono design, which uses 32 very high-current bipolar output transistors per channel, produces just 210W at 8 ohms. Available power dramatically increases, however, as load impedance decreases: 420 watts at 4 ohms, 800 watts at 2 ohms, and 1490 watts at 1 ohm. This makes it an ideal amplifier for driving speakers with punishing loads. The Wilson Audio Specialties XVX, for example, ranges from 2 to 4 ohms throughout most of the audioband but dips to as low as 1.6 ohms at 326Hz. Based on Gryphon's specs, the more punishing the load, the better this amplifier performs.

Other design features include zero global feedback, 1,040,000µF capacitor banks—more than a farad of capacitance!—2kVA toroidal transformers, low-capacitance, class-A J-FET input buffers, balanced, dual-differential class-A input circuitry followed by a fast, symmetrical class-A voltage amplification stage, DC-servo coupling, four-layer 105µm (or less) copper-printed circuit boards, and many other build and circuit features. As with the recently reviewed Gryphon Apex Commander preamplifier, the designers paid particular attention to mechanical isolation.

Three bias options are available, selectable through the front-panel touchscreen: Low for efficient, noncritical listening; Medium, which provides 100W of pure class-A while higher power as class A/B; and High, which is 100% class-A power, for the ultimate performance. The instructions caution that after changing the bias setting, the amp requires approximately 45 minutes to "settle" before the effect on sound can be assessed.

I ran the amp the entire time in High; let the electricity bill be what it may.

In the interest of energy efficiency and environmental responsibility, Gryphon incorporates a feature the company terms "green bias." When using the Apex with Gryphon's Commander preamp, the two can be linked with a special cable that allows adjustment of the bias according to programmable switching points within the preamp's volume control. I wasn't supplied with the accessory and did not test this feature.

Footnote 1: A useful tool. See Also available at—Jim Austin
Gryphon Audio Designs ApS
US distributor: Gryphon Audio N.A.
(201) 690-9006

Anton's picture

Similar to Mike's burning ampnesia....

When I was 20, the cassette deck in my car seized up and would not release the tape I was playing. My budget was too tight for a new deck, so I simply listened to that darned tape over and over and over and over for an entire year. I don't remember which tape it was.

Scott Strother's picture

Gryphon should be justly proud. I don't think I'd ever leave the house, listening to that masterpiece.
It's colossal!

georgehifi's picture

Gotta love a real amp (linear) that can do current into low impedance, and probably 1ohm as well if the test gear could take it. By doubling it's wattage for each halving of load impedance.❤️
And that can do real square wave testing (without AP class-D filters) to show the real thing, and not a imaginary pictures like the ones presented of Class-D amps square waves.

Cheers George

windansea's picture

Reading Mr. Atkinson's measurements, this beastly amp does not seem to double down from 8 to 4 to 2. Not like the Krells were famous for. Kinda weird, it's gigantic, cost no object, yet fails the ol' "double down" test.

oldslat88's picture

Sorry to see you go. Looking forward to following you at Tracking Angle.

MhtLion's picture

Michael, I’m very saddened to hear that this is your final review on stereophile. Please note you are my favorite reviewer of all time. Wish you well on everything!

volvic's picture

This beast could easily drive both my Linn Kans I & II…overkill??? You betcha!!! Damn the torpedoes!!!! What a terrific read. Godspeed Mickey, see you on the other side.

sw23's picture

I'm sure it sounds glorious. But why cram all those goodies into one box? Is there some advantage I'm unaware of?

supamark's picture

They also make a mono version, the Apex Mono for those with more room. Personally, I have room for neither :(

Mark Phillips,
Contributor, Soundstage! Network

Glotz's picture

I really wished they had this amp for audition at AXPONA this year... sigh.

Great review cutting to the truth of the sound and I am going to miss the crap out of Mikey in these pages.

Finally got to meet Mikey this year as well! He was funny and nice like always. I was too stoned.. lol. Gonna miss him but Stereophile will only get better and so will TAS.

Happy 60th Stereophile!!!

Glotz's picture

A hundred bucks more? Been thinking about Class A tube equipment recently.. I also wonder about the the additonal heat in summer.. lol.

Herb Reichert's picture

according to the specs the Apex consumes only 0.5W at idle

if that is true you will only pay to play . . . think quarter coins not c-notes


Anton's picture

I wonder which power cords they supply with it?

Glotz's picture

Thanks Herb!

supamark's picture

Sad to see you move on from Stereophile/Analog Planet, your turntable reviews are aces - I bought my Rega P10 based largely on your review, you perfectly described the sound.

Your experience with the Apex mirrors that of my editor at Soundstage! He said it stomped a mud-hole in his Boulder 2060 (a very good amp itself) with Vivid Giya G1 speakers. That's two very different speakers, made by designers with very different design goals, with which this amp kicks ass. I think we have a new contender in the SotA for amps. Time to head down to the local dealer and spend some time with a Gryphon amp.

I had to google the founder to make sure he wasn't the same Flemming Rasmussen that produced/mixed Metallica's "...and Justice for All" (he isn't, hence the "E.") but that would have been funny (both strange and ha-ha).

Mark Phillips,
Contributor, Soundstage! Network.

michelesurdi's picture

i wonder,would two hundred thousand bucks get you the same measurements in both channels?

tabs's picture

If one thing makes me sick to my stomach about the old guard it’s that Stereophole keeps making excuses for “sample deviation” and such when the highest of high end stuff doesn’t measure well. These people are charging one hundred thousand dollars per unit, and you are letting them off the hook for not delivering on basic quality control? What are regular customers supposed to expect if Gryphon can’t be bothered to provide a solid test unit to Stereophile? What does that say about their respect for Stereophile in the first place? Or their customers?

Stereophile played the same game with D’Agostino amps not too long ago that came in subpar with all sort of problems. It’s embarrassing and everything anyone needs to know about where their interests lie.

Maybe the simplest answer to all these problems at the high end is quite simple. It’s that the likes of D’Agostino and Gryphon are trading on brand and image and not on any discernible engineering advantage, and that their customers don’t really care as long as it projects the right message or has the right look.

ChrisS's picture


David Harper's picture

yes but a good argument can be made that at least the Lambo is, objectively, worth it's price. A stereo amp, not so much.

ChrisS's picture

...and counting...

Or any item in a 99cent store.

Anton's picture

I grew up in Reno, NV. We had a local Ferrari dealership owned by Bill Harrah of Harrah's casinos and car collection.

Harrah's dealership was the biggest in the world at the time, and I couldn't see why a place like Reno had such a big deal dealership. Ferraris were thick on the road in our area. We even had a Ferrari festival and annual hill climb.

I later found out that that dealership worked with his auto collection restoration department and every new Ferrari that came in had the body panels properly aligned, the stitching brought to uniform quality, the paint finish finished, etc.

His dealership prepared the cars he sold so the new owners would have what they thought they should have buying a car like that.

Maybe ultra high end audio offers a niche for buyers where a new owner could have his 100,000 dollar amp drop shipped to a "finisher" like Harrah's used to be, and the buyer, for a small additional fee (20%) would know that his new toy was performing as promised. Otherwise, how do consumers know they are getting what they purchased?

I think this could make some coin.

The prep service could even offer to make sure the units get paired with the optimal power cords, for an additional fee and purchase, of course.

I'm too old, but one of you young folks should totally do this!

ok's picture Burmester (and Kondo I think) provide indivindual measurements for every single component they make. For that kind of money they should all do the same I suppose along with a 10-year guarantee.

Jack L's picture


Agreed for gears at such hefty pricing levels.

But different bench test methods may yield not-identical data.

To measure the output power of a power amp, the dummy loads alone, can be different from the different amp manufacturers, & from different labs. Many use only a hi-power resistor as the dummy load.
Quick & easy, but it is totally different from the realworld situation: loudspeaker system !!!!

The power data thus measured is only theoretically ideal condition which do not reflect the actual output power performance when driving loudspeakers which got some complex LCR AC network, not pure resistance at all.

For Stereophile lab, a simulated loudspeaker load built up of LCR
network is used to used to measure the output power of any integrated/power amp under review. This is therefore much closer to the realworld situation an amp is loading. Therefore much more reliable performance data we can read.

Such similulated loudspeaker load already exposed the harmonic distortion vs outpower power 'weakness' of this 10-grander Danish made power amp at 4/2-ohm loads !

So "individual measurements for every single component" is helpful but not any all-cure remedy for its realworld performance.

Listening is believing

Jack L

ok's picture

..but my concern was more about quality control. This is an extraordinary amplifier no doubt, but something inside the right channel is probably broken, something that can most likely be easily fixed and individual measurements would certainly let show. In fact I think this is the main purpose of audio measurements in general and not a mine-is-bigger competition.

Anton's picture

More of a check to make sure it isn't broken!

Jack L's picture


For so expensive amps as such will surely be hand-built individually on a bench per order, instead of on a production line like parts, e.g. resistors & capacitors. The component once completely built will surely be bench tested to ensure fully functioning & complying the design specs before shipment to the dealership depots.

Heavy components, like this 500-pounder, are much more vulnerable to damage during transit from the manufacturers overseas to local dealership depots & then to customers' homes.

Good luck to the enduser customers !

Jack L

Anton's picture

When did it break and who broke it.


AnalogueFan's picture

The analysis would have been fairer if two Gryphon monoblocks had replaced two dartZeel monoblock.
Excellent Review!