Gryphon Audio Diablo 333 review

Gryphon Audio is a Danish high-end brand founded in 1985. Its first product was a moving coil step-up unit, which in many ways set the template for components the company makes to this day. Since that auspicious beginning, Gryphon’s products have always been positioned at the top end of the market, prioritising engineering purity and performance above all else.

The Diablo 333 amplifier is a fine example of the breed. It is the pricier of the company’s two integrated options, and sits in an extensive range that includes almost every part of the audio chain. The breadth of Gryphon’s output is wide for such a modestly-sized brand and includes a complete record deck, including tonearm and cartridge, alongside various phono stages, integrated and pre/power amplifiers plus a small range of not so small speakers.

Digital hasn’t been ignored either, with a number of CD players and digital-to-analogue converters on offer. The company even makes cables and furniture, so it is possible to have a complete end-to-end Gryphon system if you desire. Impressive.

That adjective equally applies to the Diablo 333 too. This beast is all about big numbers. That starts with the base price, which at £24,500 / $24,900 / AU$39,995 sits near the top end of the scale as far as one-box designs go. This integrated is chunky but not over-sized by class standards, though the all-in weight of around 50kg makes us pause for thought as we take the unit out of its smart wooden crate. You will certainly need help unpacking it if you value a healthy back, and require an equipment support sturdy enough to resist folding under the pressure of all that weight.

Design

So, 333 watts per channel into an 8 ohm load. Can we just stop and think about that absurd figure for a second? That amount of power probably makes the Diablo the most powerful domestic amplifier that What Hi-Fi? has tested in its almost 50-year history.

Astonishingly, that figure doubles as impedance halves and almost doubles again to reach 1100 watts per channel into 2 ohms. We doubt that there will be many situations where this amplifier comes up short when it comes to volume levels, in a home context at least.

However, if your room is the size of an aircraft hangar or you own some of the most electrically-demanding speakers on the planet, we suspect Gryphon would happily point you towards its even pricier pre/power combos.

Take a look inside the Diablo and its construction is just as good as you would hope for given the price. At its heart is a massive 2200VA dual mono toroidal mains transformer (a hefty 17.5kg in weight) and 68000uF of reservoir capacitance per channel. This arrangement ultimately feeds highly regulated power to different parts of the circuit, isolating the various sections from each other to keep the sensitive audio pathway as pure and noise free as possible.

Gryphon’s amplifier designs have always been dual mono in nature and this one is no different.

A dual mono design avoids the possibility of crosstalk and reduces any channel-to-channel interference, so helping to maximise the circuit’s performance, in particular when it comes to stereo imaging. The Diablo’s circuit features zero global feedback – another Gryphon trait – and operates with an ultra-wide bandwidth (0.1Hz - 350kHz (-3dB limits)) to ensure that musical transients are reproduced accurately.

Other characteristics of this amplifier’s electronic design are that signal paths are kept as short as possible and the engineers have worked hard to reduce the use of internal wiring. Both of these things reduce signal degradation.

Build & features

This amplifier’s overall construction quality is exceptional. Whatever you think of the Gryphon’s distinctive black on black aesthetic, there is no denying the quality of the build, fit and finish. Every panel lines up perfectly and the precision in terms of machining is exceptional. This is an expensive product and we are pleased to find that it has the luxury aura to back up its hefty price tag. Such things aren’t always a given with high-end products from relatively small manufacturers.

The Diablo 333 also proves slick in use. It has a 4.3in TFT touchscreen display that’s crisp and clear. The touchscreen is nice and responsive in use, making the initial set-up a breeze. It is all intuitive, allowing us to adjust everything from the name of an input and its relative sensitivity to the amount of time the display stays on with ease. You can add a pleasing remote handset to the list of positives too. The Gryphon has a nicely weighted metal unit that is simply laid-out and responsive.

High-end integrated amplifiers don’t tend to be packed to the rafters with features, and this Gryphon hardly bucks that trend. Anyone thinking of buying at this level prioritises performance, and so the manufacturers tend to remove many of the frills to maximise sound quality.

As standard, the Diablo 333 is a relatively simple line level integrated amplifier, with four inputs (including two balanced XLRs) and both fixed and variable line-level outputs. There is provision, however, to add optional modules – the PS3 phono stage (£4950 / $5600 / AU$9995) and the DAC3 digital-to-analogue converter (£6950 / $7000 / AU$11,995).

Neither is cheap, but they are neat ways to add functionality should you need it. Our review sample is equipped with the phono stage but not the DAC module.

The DAC3 remains an interesting proposition though. It is based around ESS Sabre’s ES9039Pro chipset, which ensures compatibility with 32-bit/384kHz PCM and DSD512 files. There are five inputs – USB Type B, AES/EBU, BNC coaxial x 2 and an optical. The circuit mirrors the dual mono/ zero global feedback philosophy of the rest of the amplifier and offers seven user-selectable digital filter options to allow the user to fine tune the performance to taste.

The price, just as with the phono module, is a big hurdle though, and there is no shortage of talented outboard alternatives on the market. Still, given the quality of the rest of the amplifier we would be keen to give it a listen.

The PS3 is a switchable moving magnet/moving coil phono module with the switching is done through the Diablo’s menu system. Its balanced Class A circuit follows the same dual mono/zero global feedback ideals of the main amplifier and offers fairly conventional gain values of 42dB for moving magnet cartridges and 64dB for moving coils. We are glad to note that there is a fair bit of adjustability when it comes to cartridge loading options – done through a series of dip switches – so it shouldn’t be difficult to optimise the performance of most moving coils.

Note that the phono input is done through a pair of balanced XLRs. There aren’t many record players with this connection, so you will probably need to get your tonearm’s lead terminated with the appropriate plugs if you buy a ’333. This is something your dealer should be able to help with. We used RCA-to-XLR adaptors instead, which isn’t ideal but at least allows us the chance to get an idea of how the phono module performs.

Any amplifier at this level demands top class partnering equipment. Such is the Gryphon’s transparency that any cut corners are soon highlighted. Our main sources are Naim’s range-topping ND555/555PS DR music streamer and Vertere’s SG-1 record player package including Xtrax moving coil. As for speakers, our trusty ATC SCM50 are on hand alongside Wilson Benesch’s Discovery 3Zero and the surprisingly capable Epos ES-14N standmounters.

We have our usual reference Burmester 088/911 MkIII pre/power along for comparison and the fresh memories of Goldmund’s Telos 690 (tested at £32,500 / $36,250 / AU$60,000) and the Esoteric F-01/PS-01F (tested at £27,500 / $23,000 / AU$39,000) high-end integrated amplifiers.

Sound

The Diablo 333’s huge power output is central to its sonic presentation. It should come as no surprise that this amplifier is happy to play loudly. We try all our usual bass torture tracks from Massive Attack’s Angel and Nitin Sawhney’s Anthem Without Nation to Time from the Inception OST, and the Gryphon barely breaks a sweat.

It delivers some of the most grounded and punchy low frequencies we’ve heard in our test room, and does it with class-leading composure. It is all so effortless that even our reference Burmester pre/power (180 watts per channel) is made to sound small and undernourished in comparison.

At the same time, large-scale dynamic swings come through with enthusiasm and utter conviction. There is an authority about this Gryphon integrated’s performance that is a joy to behold. As we listen to Stravinsky’s The Rite Of Spring, the Diablo delivers each of music’s seismic crescendos with an iron fist and class-leading control. The amplifier’s presentation is breathtakingly physical and set against an astonishingly quiet background.

The Gryphon delivers a huge sense of scale too, something helped by its muscular nature and the ability to render a panoramic and utterly stable soundstage. This amplifier’s stereo imaging is a real highlight, being wonderfully expansive, carefully layered and beautifully focussed. It never gets blurred, even when the music gets demanding and the Diablo is pushed hard.

As we work our way through our music collection, we find that Gryphon’s engineers have managed to combine beauty with the beast. Listening to Tracy Chapman’s debut album, we’re pleased to note that this steamroller of an amplifier is equally capable of finesse and subtlety. On Fast Car, Chapman’s voice comes through with hope-tinged vulnerability intact. The amplifier sounds crisp and articulate, delivering the song’s ebb and flow with unexpected agility.

Rhythms come through with verve and the tonal balance, though a touch dark in nature, is convincing. While we note that the amplifier is just a little subdued in the way it renders midrange/treble dynamic nuances, it remains a terrific listen, sounding sweet and light when the music demands and relentlessly powerful when that requirement changes.

We are pleased to report that the optional phono stage also performs well. It is impressively quiet in terms of noise and retains the composed nature of the line stage. Detail levels are good and music comes through in a musical and cohesive way, though perhaps not with quite the transparency required to fully justify that hefty price.

Our use of adaptors isn’t likely to have helped, so we’re willing to be open-minded as regards the phono stage’s absolute ability. We are also mindful that an outboard phono stage adds yet another box into the system, which goes against the logic of buying an integrated amplifier in the first place.

Overall, how does the Diablo 333 compare to the similarly priced Esoteric F-01/PS-01F integrated/power supply combination and pricier Goldmund Telos 690? The Class A Esoteric sounds even more delicate and fluid, delivering a sweet full-bodied sound that’s an absolute pleasure. But, at just 30 watts per channel, it simply can’t compete with the Gryphon’s muscularity and scale. The pricier Goldmund is a more precise and articulate performer, and notably more neutral in balance. It is decently muscular too, though not to the Gryphon’s level.

Verdict

Regardless, Gryphon’s Diablo 333 proves a wonderfully versatile performer. It can speak quietly and wield a big stick at the same time, and that’s a talent worth having. Rarely have we heard such a powerful unit sound so fleet footed and musically cohesive.

In recent months we’ve been fortunate enough to test some world-class integrated amplifiers. We are pleased to say that the Gryphon’s Diablo 333 should be counted among them.

First reviewed: March 2025

SCORES

• Sound 5
• Build 5
• Features 5

MORE:

Read our review of the Esoteric F-01/PS-01F

Also consider the Goldmund Telos 690

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