The GRYPHON DIABLO 300 integrated amplifier is thoroughly evaluated by Howard Milstein.

I had been waiting a while to be able to hear and review this “monster” of an integrated amplifier and thanks to Anthony Chiarella, (marketing director) and Rune Skov(sales director) it thankfully and finally came to fruition.

Rune Skov

As with previous reviews of integrated amplifiers, lots of audiophiles have learned about the benefits of the finest, single-chassis units available. Notwithstanding Gryphon’s infinite high-end separates as well, (e,g. their essence and Apex series).  

Many of today’s most eclectic designers are producing sophisticated integrated systems that offer equal performance to a system made up of pricey separates. The Gryphon Diablo 300 dual-mono integrated amplifier is such an example.

The Diablo 300 comes in a case that is more akin to a Sherman Tank than that of the original Diablo and the gargatum 300 features zero negative feedback, a genuine Dual Mono configuration, a 43-step fully balanced relay volume attenuator, and ultra-precision resistors.

Flemming Rasmussen, Gryphon’s designer, exposes once more something uncommon in our profession with just a glance at the aesthetics. Super clean, huge, beautifully constructed, and ergonomically inebriating are just some of the byproducts of this Diablo 300. Before we undertake the evaluation of this amplifier’s subjective sound qualities, let us look a bit under the hood and within the technical parameters of the Gryphon Diablo 300.

In theory, the way the Diablo is built should ensure that it is, at leas, one of the greatest sounding amplifiers in the world, regardless of price or brand. Some of the design parameters listed here should fortify this assumption.

If you take a quick look at some of these key features below it tells the story very well, but of course, there is much more to this amplifier, including:

  • True Dual Mono configuration
  • Zero negative feedback
  • Microprocessor-controlled 43-step fully balanced relay volume attenuator for best sonic performance based on a minimalist contingent of ultra-precision resistors
  • Ultra-short signal path
  • Minimal internal wiring
  • Military spec. dual-layer and four-layer printed circuit boards with up to 105-micron copper traces
  • Dual Mono Holmgren toroidal transformer with vacuum treated core and windings to virtually eliminate mechanical noise
  • New, high-speed, discrete single-ended Class A input buffer for best possible sonic performance

In addition to the above, It would appear to be quite mandatory to add these two important technical details:

1-The Massive Heat-Sinking: the Diablo 300 has more surface area devoted to cooling transistors and internal circuitry than other most other Integrated Amplifiers (the entire aluminum chassis functions as a heat sink) which enables Gryphon to run the outputs at his-bias while keeping the amplifier cool and in the long term, quite reliable.

2-Its Mechanical Stability: Diablo 300, uses a massive, rigidly-constructed chassis that offers a remarkable degree of damping and vibration control, allowing sensitive electronic circuits to operate without degradation from vibration or mechanical noise. This attention to mechanical stability provides the ideal foundation for optimal circuit performance.

Unsurprisingly, Diablo 300 does not employ negative feedback. A creative avoidance of the inherited time delay anomalies that are typically produced when the output signal is transmitted to the comparator loop at the input, as required creating intermodulation distortions, is undoubtedly one of the approach’s few benefits.

Furthermore, the voltage amplification stage of the Diablo 300 now employs low capacitance pre-driver transistors with the enhanced current.This results in a huge, extended frequency bandwidth and a higher slew rate, which translate into a massive musical energy flow.

With a frequency range/response of 0.5 Hz to 350 kHz, the Diablo 300 is quite amazing. The nameplate 300 stands for, undoubtedly, three hundred watts into an 8-ohm load. This is a significant improvement over the original Diablo and doubles into 600 Watts over a 4 Ohm load before reaching the impressive 950 Watts into 2 Ohms.


Well, yes and no. The amplifier features high current, high gain bipolar transistors, allowing it to operate in pure class A for the first 5–6 watts with a very high current before switching to A/B mode.

As such, The Diablo 300 will definitely be able to drive practically any speaker in the world thanks to its amazing control and use of a big power supply with a total power capacity of 136.000 uF.

Those first few watts of Class A power were a bit hard to tally out in the listening sessions with the Diablo, but there was no doubt that the amplifier was presenting a huge amount of clean and blissful power reserves with all the speaker systems it was connected to in this review.

I talked to Sales director, Rune Skov about some of the above-specified intricacies that enable the Diablo to work and sound as it does. I asked Rune to specify some little-known and appreciated technical attributes that have had a huge influence on the sound of the Diablo 300:

“One of the main reasons is the microprocessor-controlled 43-step fully balanced relay volume attenuator based on a minimalist contingent of ultra-precision resistors. Using the attenuator (type of volume control) eliminates a lot of noise and the attenuator will have very little overall influence on the sonic performance. Normally the volume control is the weakest link when talking about a preamplifier or the preamplifier part of an integrated amplifier. But in this case, it will have a minimal influence due to the design topology.

Another thing is the incredibly short signal path and using a minimum of internal wiring. When adding a cable to the design the character of the amplifier will change and it is getting more and more difficult to control the sonic performance while getting closer to the goal of creating an almost sonic-neutral amplifier.

The true dual mono topology is also a key factor for the performance as we want to get as close to maximum channel separation as possible. Of course, it could have been completely mirrored amplifier and power supply boards like in the more expensive amplifiers, but we are at an incredibly high level of electronic design and amplifier topology in this current design”.

“We are also using some other features but they are a confidential part of our design philosophy and enable us to maintain the top position in the market for luxury high-end audio equipment.”

Out back are those huge binding posts, two balanced (XLR) inputs, three unbalanced (RCA) inputs, a dedicated subwoofer, and tape outputs, an AC fuse, a ground post, an IEC power outlet, and numerous 3.5mm trigger connections are all located on the back of the device.

The upper, center portion of the rear panel is occupied by a blocked bay, marked Optional Module, for the separate moving-magnet/moving-coil phono stage. A dealer or manufacturer can install these.

The front panel of the device has all the major controls, making it completely usable even without a remote. Although I only used the superb remote towards the end of my time with the Gryphon, I can say that the design of this remote control is a separate story within itself. Indeed, you won’t be able to forget it after you have seen it and used it. Diablo’s front panel is ergonomically useful, and stunning to look at. All the main functionality is here; on/off button, up and down input selection, mute button, and of course volume knobs to lower and raise the volume. It must be noted that the manual volume control buttons are very “touchy” in use. Be careful to keep a light finger touch when adjusting them as they can jump very fast if not used carefully and insightfully.


The sample I received of the Diablo contained its own internal DAC, but no phono stage. The DAC is equipped with the highly respected ESS Sabre ES9018 chipset as well as asynchronous USB, AES/EBU, optical, and twin S/PDIF coaxial connectors.

The remaining inputs can only accept signals with a resolution of 24/192 PCM, but the USB input can accept signals with a resolution of 32-bit/384kHz PCM and DSD512

Through Diablo’s formative menu system, the Gryphon DAC module enables the use of customizable PCM and DSD filters. On the PCM side, there are digital filters with slow roll-off (short group delay) and sharp roll-off (long group delay), while on the DSD side, there is a first-order analog filter that may be turned off.  

Ultimately, I was able to add a separate phono stage to the proceedings which gave some excellent results when vinyl records were employed for the subjective listening tests. As for how this huge reservoir of an amplifier showed itself on its own, some perceptive observations were made.

The first thing that hits you as you listen to the Gryphon is its amazing power output and how it controls the overwhelming aspects of the loudspeaker in use. Huge transients can be heard as the sound incorporates a detailed quality from all program sources that are permeated throughout the listening room.

When it comes to transients, The Diablo 300 seems to have an appetite for emphasizing the attack of the notes. However, they allowed the note to emerge distinctively, and a bit singularly. No, this was not a “bright” sound by any means. Instead, it seemed mostly spot-on in its treble response, though once in a while, stringed instruments showed a touch of “bite”– thereafter decaying quite naturally and unrelentingly.

With many recordings of all genres, the unit will accurately expose any artifacts that are understated in the recording or indeed, your full system itself. This amplifier jumps at you with its acute display of recording ambiance, be it studio or live recordings while introducing an arousing, slightly extended top end. In the final analysis, the Gryphon displays the above in a somewhat “reserved” yet quite explicit reproduction quality that your ears catch and appreciate immediately.

It’s easy to ascertain that one can almost “touch” the instruments and players on the soundstage as the Diablo digs in and exploits its most explicit work. However, this never interferes with the unit’s delectable bits of nuanced detail, intimacy, and that neutral “you are there” quality of reproduction.

I believe most users’ first impressions when the Diablo 300 starts to play is one of huge impact, a naturally smooth, slightly tonally “explicit” frequency response while at the same time preserving a “dynamically polished” impression of sound to the listener. This “hallmark” of the Diablo 300 will vary of course depending on your upstream components, cables and ultimately your preferred loudspeakers.

Even when pushed hard, Diablo’s treble remains clean and mostly elegant; even throughout complicated musical passages, while never losing its composure.

The midrange and vocals can sound huge and alive, full of energy and expression, or at lower volumes, extremely focused, clean, and tight sounding with great resolution, depending on the source or DAC involved.

Considering what I have said about the source material, the Diablo 300’s bass quality immediately caught my attention and has a very distinctive sonic character. It is infinitely full-bodied and “deep” with enduring “slam” in the lower registers and a tight mid-bass response on all music, be it pop, rock, or classical material.

Furthermore, the Gryphon Diablo seems to fully ‘light up the sound stage with subdued ‘exuberance’, yet a delicately displayed audible character as you listen to an abundance of different sources; be it digital or analog that may be at your disposal.

As for the midrange itself, it is quite transparent, maybe a bit “honed” in its response, and ever so intricately “clear cut”, particularly with well-recorded acoustical instrumental and vocal recordings. Be prepared for this amplifier to show up poorly engineered recordings without any type of hesitancy whatsoever!

On the other hand, when you get a masterful vinyl or CD performance introduced to the Gryphon, the unit has an uncanny type of quality that puts the tonality of the performing instruments almost right at the heart of your listening seat. The amplifier exhibits fine soundstage depth and considerable width from the loudspeakers themselves.

Interestingly, this Gryphon does not need hundreds of hours to get itself into great physical shape. With the Diablo left on for only a few days, you can hear and feel its muscle and delicate musicality that is displayed quite easily….it is an amplifier that is extraordinarily cultivated, be it at lower volume levels or intensely higher levels as to how it plays your most discreet musical tracks.

Comparatively speaking, there is only one other integrated amplifier on the market that can equal or exceed the sonic impact of the Diablo 300; and this unit is exactly DOUBLE in price! What does that tell you about this integrated amplifier’s overall prowess?


The in-built (add-on) Gryphon DAC was a huge benefit because it enabled me to learn the truth about how this amplifier sounds in full. The DAC fitted, is fully adaptable and the Diablo 300 has slots that can accept alternative modules to expand functionality including another extra, premium MM/MC phono module that can be ordered immediately or bought later, as soon as funds permit.

For the review, I tested 3 different optional DAC configurations, including the BorderPatrol SE-1 as well as the Denefrips Pontus. My usual Audio Note CD3.1/x2 was also there for CD usage. There were some intriguing variations in sound that were observed between all 3 units when combined with the Diablo 300, including some minute and other somewhat more tactful differences.

After some robust auditioning with Diablo’s full system intact, I first inserted my reference BorderPatrol SE-1 into the system using my Audience Studio One interconnects to get a grip on any sound performance changes observed. As is the hallmark of the BorderPatrol, a touch of tube lushness was observed which quickly increased the ambiance and some spatiality to the sound. I quickly found it a bit more seducing than the much more expensive inboard DAC of the Diablo 300, though a touch of midrange structure was covered up by the former at the expense of some pensive detail and “immediacy” displayed by the Gryphon.

The next challenge to the mighty Diablo was the Denefrips Pontus, R2R (review forthcoming) which I had been auditioning for a month or so. The Pontus is an extremely neutral and natural-sounding DAC and it invigoratingly exposed its sound quality as such. However, If you prefer the audible perception of a more “engraved” or cutting-edge sound quality, the Diablo 300 DAC has this in spades. When placed against the Denafrips, the question of which is more natural would be a matter of opinion, although once again, the Pontus’ easy, and beautifully smooth sounding DAC can be had at a bargain price for the taking.

Thereafter, things quickly turned around when I fed my Audio Note CD3.1/x2 into the picture. Here the sound became much more romantic with those tubes in the Audio Note’s output stage. Tube aficionados will appreciate this as the sound enveloped into a detailed, yet unquestionably more luxuriant and enveloping quality that the Audio Note always exhibits to its utmost.

Ultimately, my recent sample acquisition of the new MoJo Audio “Mystique X” R2R DAC was put between the Audio Note Transport and the Diablo 300. This unit was only burnt in for a day or two but I was a bit overwhelmed by the sonic impression it added to the Diablo 300. (I am still amazed at the small, but important differences in sound quality observed between different DACs and their contrasting design attributes!)

To be brief, the Mystique brought forth to Diablo some of the finest musicality and tonality from recorded music that I have heard in my system up to now. Mind you, this is just some initial impressions so wait a while for the full review.

As one can see from the above, the Gryphon Diablo 300 was able to perform magnificently with every outboard DAC it was paired with, and yet — comparatively speaking, its inboard DAC was able to bring forth a sound quality that left very little to be desired, particularly considering this amplifier’s steep price.

Some short listening time with my non extravagant, yet completely crystal clear and heartwarming vinyl setup brought forth similarly exquisite results when adding on a separate moving coil phono stage. Depending on your specific phono cartridge of course, and it’s mid to high-frequency neutrality, (the ZYX Bloom 3  in my case) the sound quality will be overtly rich and satisfying. This titanic of an integrated amplifier worked wonders both digitally and with analog vinyl setups to quite an extraordinary magnitude…as it should for approximately $16,000!


Arguably, there is only one integrated amplifier that I have used that can be compared to the Gryphon Diablo 300; that is the darTZeel CTH -8550 MKII, which I reviewed late last year. In this respect, the darTZeel is double the price of the Gryphon, but for the most discerning audiophiles, this level of quality must be addressed and compared for those enviable users to differentiate the two units.

The Gryphon has a bit more usable power reserves to bait all types of high-end loudspeakers of varying loads, giving it a huge punch of brute force when the source material permits. Its sound is intricately detailed, transparent and a touch leanly balanced in its formatively “goldenesque” midrange while the high frequencies are as sweet and reserved as can be discerned.

Alternately, the darTZeel has a massive amount of undeniably dashing “magical” musicality abound and throughout its full frequency spectrum while offering a build quality that is quite on par with the Diablo 300. However, all of this incontrovertible majestic ‘splendor” comes at a price — and it is here that some users and enthusiasts may not be able to fully justify it. 

What the Diablo 300 has over the former amp is a plethora of optional add-ons that are immensely useful to build upon if and when you ultimately need them as well as a comparable, though considerably different style of sound reproduction; not to mention being half the price of the darTZeel!


The Diablo 300 from Gryphon Audio Designs is an esoterically distinctive and captivating audio component. Its build quality is superb, and its aesthetic and electronic design are akin to almost any integrated amplifier I’ve seen and/or listened to in a high-end component.

This Diablo 300 is made to effortlessly swallow up any speaker on the market; even when with the most difficult loads. When giving the amp a lot of coercion, it showed no signs of strain whatsoever; producing some of the most engaging and accurate musical representations I’ve heard from an integrated amplifier, let alone almost any amplifier I’ve had in my listening room up until now with quite a stunning sound quality.

This unique and absolving audible character is distinguished by a golden, rich, svelte midrange, a fully intensive bass response, and pleasantly extended highs.

The Gryphon Diablo 300 is not a moderately priced component by any means, coming in initially at approximately 16k dollars. Not a pittance for most audio enthusiasts, but what this immaculate machine has to offer is most profound in almost every way. If you are in the market for an integrated amplifier at this level of performance, The Diablo 300 is the only way to fly!

Review system for this product:  Loudspeakers: Harbeth Compact 7ES-3 XD loudspeaker ~ Quad ESL-63, Spendor BC1, ~ Digital: Border Patrol DAC SE-I ~ Innuos Zenith Mk.3 server/streamer ~MoJo Audio ‘Mystique’ X DAC, Denafrips Pontus DAC, Audio Note (UK) CD3.1x/2  Analog: Audio Technica LP-7/ZYX Bloom 3 mc cartridge  Amplification: ~ Pass Lab XP- 12 preamp ~ Pass Labs XA30.8 power amp ~PS Audio M1200/ Cambridge Duo MC/MM ~ Rotel Michi 350 integrated amplifier / Cables/ Conditioners: Inakustik AC-3500p power station & LS-4004 speaker cables, AC-2404 reference Air Power Cord ~ Audience Studio 1 interconnects, speaker cables, Clarus “Crimson” 75-ohm digital spdif / Audio Art 1 e” AC Power

Gryphon Diablo 300 integrated amplifier base price: $16,000 USD.

Company Information
Gryphon Audio Design
Industrivej 9
8680 Ry

United States of America Distributor
Gryphon Audio NA Inc.
9 Lynn Court,
Woodcliff Lake, NJ 07677

Voice: (201) 690-9006


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