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For a reviewer it’s very easy to claim that a given component competes with or surpasses others twice as expensive whilst conveniently failing to identify the references. I have fallen for that trick too. For one thing it avoids unpleasant phone calls and emails. Although I won’t return to this, the Diablo in my system did best separates twice as expensive - not by much and valid only for listeners with my inclinations but very real nonetheless. On paper, Gryphon's amplifier recipe is very simple: true dual mono operation for perfect channel separation; true class A operation for perfect linearity and an absence of switching distortion; massive heat sinks and even more massive power supplies for unlimited dynamics; and balanced circuitry for lowest possible noise. Obviously there must be a few secrets to this mix as otherwise anybody could/would design a Gryphon Colosseum. Nonetheless the fundamentals remain well known. What sets the brand apart from the few others who’d even venture into high-power true class A amplification is the ultimate level of refined execution.

Because of its more manageable footprint, higher power and targeted price, the Gryphon Diablo had to forego pure class A operation for class A/B yet its very significant heat dissipation has me suspect that it operates in class A well beyond the first 7 of its 250 watts (250 watts into 8, 500 into 4 and 800 into 2 ohms – impressive for a one-box integrated). The rest of the core recipe remains unaltered with double mono, balanced circuits, zero negative feedback and an oversized power supply. The beast’s front panel offers a very legible alphanumeric screen displaying the input (each can be independently named) and output level; and touch buttons to changing source and volume, mute and monitor and to access the setup menu. Amongst the menu’s hidden features is the ability to assign max and turn-on volumes (0 is default which is where I left it to avoid potentially loud surprises). The menu also allows for setting the third input as HT bypass to drive the Diablo’s power section directly from an A/V processor.

The back panel provides one balanced input, four RCA inputs, one set of fixed outputs and one set of variable outputs to connect to either subwoofers or a second amp. One of the inputs can be fitted with an optional MM/MC phono module but the review loaner was not so equipped (all phono comments were thus based on using either the Esoteric E03 or Nagra BPS phono preamplifiers). The speaker binding posts are massive custom affairs accepting spades or bananas without issue.

The Diablo proved absolutely foolproof in use, the elegant remote allowing easy change of volume and source whilst controlling also mute and standby functions. Speaking of standby, here is my only practical caution. This amplifier sounds good out of standby but much better after 45 minutes of warm-up. I found it consistently better after 24 hours yet. By not running pure class A, it is conceivable to leave it powered up continuously for best sound even though that’s not the environmentally friendliest thing to do and certainly can make for cozy summer sessions since the Diablo runs warmer than my pure class A low-power FirstWatt F5. At minimum you’ll want to place the Diablo on a tall shelf with plenty of surrounding breathing room rather than build it into a wall or tight rack. The review loaner sat on an ASI HeartSong amp stand fronting all other gear and I would not put it inside the rack itself.

Not being a recent product release, I had the advantage over my fellow reviewers. I could peruse their findings before reporting mine. What struck me was thinking that we weren’t reviewing the same amplifier at all. One writer described the Diablo as cold and lacking in emotion. Another called it warm and organic, yet another neutral and fluid. The only thing we all seem to agree on is the phenomenal level of resolution, detail retrieval, ambience recreation and dynamics this amplifier is capable of. In an attempt perhaps to reconcile seemingly opposing views, I’ll add that the Diablo is utterly transparent to the rest of your system, chosen playback material included. This admittedly is something reviewers often say when otherwise feeling at a loss to describe a component’s sound more specifically. Even so, the Diablo had this quality more than any other component I reviewed to date. Everything and anything mattered when it came to the overall voicing of my system. Beware that if you fall for the Diablo's charms, you might spend a lot of time tweaking your system not because you need to but because you now can hear these often small differences so very clearly.

There are some aspects of the Diablo's sound that are its own. Starting with dynamics from massive explosions to the finest of micro fluctuations, this amplifier had the most explosive unrestricted range I have heard. 6moons regulars know that for two of our writers, one of our absolute references for low-level dynamics is FirstWatt’s F5 whenever a mere 25 watts aren’t a practical limitation. Microdynamically the Diablo was at least as nimble.

Muted string pizzicatos from Britten's Playful Pizzicato bristle no matter how low you listen over either amplifier. This translates into amazingly clear transients that are sharp in a good way. A harpsichord is probably one of the most challenging instruments to reproduce. Dull its needle-like attacks and it will sound like a dead toy piano. Over-sharpen them and get holes drilled into your temples. Switching to Padre Soler's Fandango and Sonatas with Scott Ross, a long-time favorite, the instrument was in the room no matter how low I turned down the volume.

The dynamic qualities of Scott Ross' playing remained intact. At very low levels his music eventually scaled down in size but the sharp pinch of the strings never dulled or rounded over as it does sooner or later over all amplifiers - even the F5.

Production line of Gryphon Colosseum amplifiers

Where the Diablo then simply trounced the Nelson Pass design was with macrodynamic explosions. The rise of both amplifiers seemed equally fast (a tad faster for the Diablo perhaps) but the Dane could differentiate dynamic levels to an even greater extent especially on the most massive of orchestral pieces. That was easy to hear. Take the last minutes of Saint-Saëns’ Symphony with Organ, an utter orchestral mayhem with the organ going pretty much all out yet at the very end still adding the kettle drums for the final thunder. With the F5, the drums entered. With the Diablo they exploded. There seemed no limit to where this amplifier could go.