D’Agostino Relentless monoblock amplifier unveiled at High End 2018

relentless monoblockDan D’Agostino introduced us all to his new, and aptly named, Relentless monoblock amplifier via a FaceBook live stream from the Munich High End show.

This piece of “audio jewellery” is a fully balanced amplifier. With the positive and negative matched precisely D’Agostino explained that this cancels out any distortion. Handy when this amplifier is rated at 1500 watts at 8ohms and a mighty 6000 watts at 2ohms. The first 100w of that output is pure Class A.

Relentless power

relentless monoblockFirstly, let’s kick off with the power supply. The core is a transformer that uses multiple sections running in concert. These are all potted and encased in a metal shield. This design reduces transformer noise to near zero and protects the audio circuitry from the transformer’s magnetic field.

The transformer feeds a custom-designed rectifier circuit and a 600,000-microfarad/100-volt capacitor bank. A special holder mechanically grounds each capacitor so there’s no vibrations. Finally, a slow-start circuit activates the power supply in stages, eliminating concerns about capacitive inrush tripping household circuit breakers. D’Agostino joked that switching a pair of these things on in a typical home won’t cause the lights to dim.

Additionally, there’s the Dan D’Agostino’s exclusive Super Rail concept in play too. This makes maximum use of the incredible resources of this power supply. Super Rail employs higher voltage rails in the sections prior to the output stage, effectively “turbocharging” the amplifier and exploiting the full capability of the output voltage rails which improves dynamics, lowers distortion, and tightens the amplifier’s electrical grip on the speaker.

Hot stuff

relentless monoblockThe Relentless monoblock’s unique heat sink combines copper and aluminium in what D’Agostino called a “thermal engine”. Essentially, this wicks heat away from the connected devices.

The elaborate elliptical design expands on the venturi heat sink first explored in the Momentum series. This ensures that the Relentless Monoblock runs safely and reliably even when delivering its full rated power. Thermal, short circuit, and DC protection are included in a non-invasive but comprehensive defense against any external system faults.

Furthermore, the entire chassis of the Relentless is machined from solid aluminium, for superior shielding, thermal stability and vibration damping. High-precision milling allows the entire chassis to fit together solidly with no visible fasteners.

The amp’s new power meter measures more than 8-inches in diameter. The meter’s range and response automatically adjusts to the level of the incoming signal.

Hook up

In keeping with the tradition that started with the Dan D’Agostino Audio Systems Momentum amplifiers, Relentless offers a single XLR balanced input. Speaker connections are made using massive binding posts made from gold-plated brass. Moreover, these feature washers and spacers. To further ensure that you get the tightest possible fit between your speaker cable and the post you also get a carbon fibre hand wrench with each amp.

Lastly, the amplifier stands on a set of 307 carbon stainless steel feet that are rounded so as not to damage your floor. At just under 500lb (around 22okg) each, spikes would just see this thing burrow in to any surface.


The D’Agostino Relentless is priced at $250,000 a pair. A Relentless pre amp is also currently in the works.

Relentless specs

Frequency Response20 Hz to 20 kHz, ±0 dB
<0.1 Hz to 100 kHz +0/-3 dB
Signal-to-Noise Ratio>113 dB, wideband, unweighted, ref. to full power output
Gain26 dB
Total Harmonic Distortion<0.007% at 1 kHz, at 1,500 W, 8ohms
Input Impedance100 kohms
Output Power1,500 W RMS at 8ohms
3,000 W RMS at 4ohms
6,000 W RMS at 2ohms
Output Voltage320 V peak-to-peak
113 V RMS
Output Current400 A peak
Slew Rate100 V/microseconds
Output Impedance<0.03ohms, 20 Hz to 20 kHz
Damping Factor>267, 20 Hz to 20 kHz, ref. to 8 W
Power ConsumptionStandby: 40 W
Idle: 400 W
Maximum: 10 kW
Inputs1 balanced via XLR connector
Outputs1 pair binding posts
Dimensions22.5 x 11.5 x 32.5 in (whd)
57.2 x 28.0 x 82.6 cm (whd)