No name is more closely associated with high-end audio amplifiers than that of Dan D’Agostino. During his career of more than 35 years, D’Agostino pioneered countless advances in the design of amplifiers, preamplifiers, CD players, and surround-sound processors. He is known as the audio industry’s most passionate promoter of high-quality, high-powered amplification. Makers of the world’s finest loudspeakers rely on D’Agostino-designed amplifiers for their most important demonstrations.
Dan D’Agostino was founder and chief engineer of Krell Industries through 2009. Since the inception of DDMAS in 2011, energized with a new organization and new state-of-the-art designs, the products that bear his name not only achieve new levels of sound quality, they also look like nothing else in the industry. The new designs combine an elegant aesthetic flair coupled to inventive circuit topologies and innovative materials.
Starting with the Momentum Mono amplifier, the D’Agostino product line now extends upwards to the awe inspiring Relentless Mono amplifier and outwards to the new Progression Integrated amplifier. The Relentless Mono Amplifier is an all-out assault on the amplifier category. Capable of driving any speaker to its fullest capability, the extraordinary power output of the Relentless Mono is only matched by its sublime low volume sound quality. The Progression Integrated amplifier connects the high-performance core of D’Agostino products to the exciting world of streaming audio with Tidal, Quobuz, and Spotify services as standard offerings.
As impressive as these designs may sound on paper, the only way you can truly appreciate their warmth, detail and unmatched beauty is to experience them at your nearest Dan D’Agostino Master Audio Systems dealer.
Combining engrossing sound quality, a flexible platform, and striking aesthetics, the Relentless Preamplifier is the ultimate centerpiece for a truly brilliant audio system.
Created for uncompromising listeners and needing three chassis to execute, the Relentless Preamplifier elevates every aspect of preamplifier design. Individual audio chassis and power sections ensure complete isolation from noise. Audio and power signals are carried through interlocking feet shortening signal feeds to the absolute minimum.
The standard model can be augmented with a plug-in digital streaming module including legacy digital inputs, network, and internet music streaming. Tidal, Qobuz, Spotify, and Roon are all directly supported. An iOS app makes for easy, intuitive operation.
The new Relentless Preamplifier is the ultimate in preamplifier design. The preamplifier plays a critical role in musical playback; the point in the reproduction stage when the music signal is particularly susceptible to compromise through noise and distortion. The use of three separate chassis in the design of the Relentless Preamplifier—a dedicated audio chassis for each channel separated by a power supply/control section—addresses these challenges and brings other benefits as well.
Positioned between the two audio channels, the power supply makes use of extensive electrical and magnetic shielding to keep radiated interference out of critical preamplifier circuits. Internal line conditioning circuitry filters RF noise on the AC power and compensates for asymmetric power waveforms and DC on the mains. Power for the preamplifier stages comes from two 150 VA toroidal transformers – one dedicated to the analog circuitry and one for the digital and control circuitry. These transformers drive an 8-amp bridge rectifier and 26,400 microfarads of filter capacitance. The two regulators for the analog stages are scaled-down versions of those used in the Relentless Mono amplifier. The separate digital regulator is a monolithic platform with thermal and current limiting protection in the unlikely event of a fault. The Relentless Preamplifier has nearly as much power supply capability as many power amplifiers.
The input stage in each mono preamplifier is the result of a design experiment for a circuit that hadn’t been used in any previous D’Agostino preamplifier. As part of development, a version was tested in the existing Momentum Preamplifier. The overwhelmingly positive results led directly to the launch of the Momentum HD Preamplifier. From there, the fullest expression of this idea was developed, and the Relentless Preamplifier was underway.
The audio circuit topology starts with a new discrete differential FET input stage featuring a voltage input signal capability of an extraordinary 30 volts. With an input impedance of over 1 M Ohm, the Relentless Preamplifier’s front end is immune to source related electrical issues. In normal operation, component heating can lead to performance and sonic degradation. Developed specifically for the Relentless Preamplifier, a unique circuit maintains a stable bias so that temperature related anomalies are offset thus preserving performance during extended listening.
Featuring only balanced XLR inputs the Relentless Preamplifier topology rejects common-mode input noise over an unusually wide bandwidth. All signal gain is realized in the current domain using proprietary multiple-output current mirrors with nearly 30 times the linearity of other designs. Executed with four-layer circuit boards for superior signal quality. The use of four-layer boards dramatically reduces distortion and propagation levels as compared to the more commonplace, two layer boards.
The analog and digital circuit elements are isolated, including ground planes, from each other. Where necessary, digital control signals are optically coupled to analog circuits. The signal switching relays are hermetically sealed and use gold-plated contacts for maximum signal integrity.
Utilizing no negative feedback anywhere, core D’Agostino circuit concepts include a signal path that is fully complementary and balanced from input to output achieving a frequency response flat to 120 kHz.. The overall result is a musically dense and dynamically rich signal presented to the balanced outputs.
Arguably, the most striking element of the Relentless Preamplifier is the pair of volume controls fronting the two audio chassis. Volume control circuits are often overlooked, if not actively minimized, in preamplifier designs. This is not the case in the Relentless Preamplifier. Each volume control is constructed using 14 separate metal components ensuring the smoothest response and control of the military-grade, high-linearity solid-state switches and discrete precision resistors employed in the volume circuit. The bandwidth and transient response of the Relentless Preamplifier is completely unaffected by the volume setting. As a result, high frequencies sound especially smooth and extended, and music emerges from “jet black” silence.
The volume settings are displayed via the elegant swiss watch inspired volume wands or can be displayed numerically, from 0 to 99.
The Relentless Preamplifier is a two source/two zone preamplifier. This means that the Relentless Preamplifier can simultaneously control the switching and volume of two sources in two separate rooms or zones. Listening sources may be two analog sources or when equipped with the optional digital streaming module, one digital source and one analog source. In a one zone system, either volume control will adjust volume in the main room or Zone 1. If two zone operation is desired, the upper volume control manages the Zone 1 volume and the lower volume control adjusts the Zone 2 volume.
Housed in machined aluminum and copper, the Relentless Preamplifier remote control is a comfortable design operated via touch pad. Control buttons are minimized with most of the operation executed by navigating via a tactile touch pad. Bluetooth 5.0 technology extends the usable range of the remote control and eliminates the line-of-sight issues that plague conventional infrared designs. New for the Relentless Preamplifier is bi-directional remote-control functionality. All adjustments made on the Relentless Preamplifier front panel are reflected on the remote control’s display screen including input, volume, and balance selections.
117 E Union St
(626) 793-7229
5235 Avenida Encinas
Ste #A
(760) 814-8009
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