Pre/Power Amplifiers

Lame analogies – both banal and obvious – spring to mind when one is directed to review an amplifier which is a little over half the power of its predecessor. One thinks of cars offered with engines of half the horsepower of a dearer sibling, of second growth wines, and other half-pint offerings. But the D’Agostino Relentless 800 Mono Amplifier – a heady £236,000 per pair – delivers the wattage that provides its model name: 800W per chassis. And that is conservative.

The original Relentless monoblock – CEO Dan D’Agostino’s ‘dream of an amplifier without limits’ – is now superseded by two siblings, the massive Relentless Epic 1600 and ‘baby sister’ Relentless 800 (with no Epic in its name), seen here. Let’s get the physically daunting stuff out of the way first...

Each Epic 1600 monoblock weighs 258kg, the 800 a marginally more manageable 145kg. Lucky owners will welcome a team of beefy shleppers when receiving either. Once in situ, you will not be moving them around. Halving the power may have halved the weight, but you still need two spaces on the listening room floor to accommodate each of the 800’s 549x264x660mm (whd), which is a limited saving over the 1600’s deeper, wider and taller 572x280x826mm (whd).

Needle Match
Available in silver, black or custom finishes, with a distinctive copper trim, the Relentless 800 dominates the view in front of the listener almost as much as would any loudspeaker. This is not a discreet little block of chocolate like a Meridian amplifier of yore, nor a Quad 303 the size of a loaf of sourdough. The Breguet watch dial-inspired meter, a D’Agostino signature, glows a comforting green but its ‘time-keeping’ is less accurate... As its moon-tipped needle swings past the midday position the amp is delivering a little under 20W/8ohm, not the indicated 800W, as confirmed by PM. It will deliver this sort of power but, by then, the needle will be hard right and your speakers firmly in the red zone. Truth is, such is the power of the Relentless 800, if the metering were accurate then you’d barely see the needle twitch!

Once installed, these are as set-and-forget as any good amplifier should be. The sides of each chassis are channelled for convection-style cooling, while the top is suitably vented to keep the heat at bay – so no egg-frying safety issues emerged in our testing.

Around the back, the unit reaffirms Dan D’Agostino’s insistence on robust connectivity suitable for a powerhouse. Inputs are on balanced XLR only, while the solid copper speaker terminals are designed for spade lugs, not 4mm bananas. A toggle at the rear turns on the power, while a soft-touch button under the fascia – another D’Agostino hallmark – switches the units on from standby. As this might inconvenience some, eg, those as slothful as I, the back panel also has 12V trigger sockets for system-sync’d switch on. Lastly there’s an industrial-strength 30A locking connector for the AC mains, another touch which tells you that Relentless models are built like military materiel. Wusses need not apply.

Trickled Pink
As explained in our interview with Dan, devising a half-power (or thereabouts) version of the 1500W original was not simply a case of reducing the number of active devices or the capacity of the power supply. In practice, the company’s development of its MxV amplifiers [HFN Aug ’22] affected the entire range of models, with ‘trickle-up’ technology transitioning the original Relentless Mono amplifier into both 800 and Epic 1600 siblings.