
Overview

Reviews from America's best.
When one of America's best-known audio reviewers described our original Hercules amplifier, along with our Altair preamp, as "the most transparent, detailed, and cleanest electronics I've heard," we knew our "dream team" of top audio engineers and industrial designers had achieved its goal: to create the world's best amplifier.

A revolutionary twist.
The Hercules II Mono employs a revolutionary twist on the concept of a fully balanced amplifier. In all balanced amplifiers, mirror-imaged amplifier circuits are used, with one part amplifying the positive half of an audio signal, and the other part amplifying the negative half. Yet in other balanced amps, the two halves are not quite equal, because one uses N-type transistors and the other uses P-type transistors. Hercules II achieves an essentially perfect balance by combining two matched single-ended amplifiers using only N-type output transistors. Every element of the musical signal passes through exactly the same types of circuit components, maintaining all the musicality of the original single-ended module.
Features
1,000 watts of power into 8 ohms
With 1 kilowatt of rated power into 8 ohms (and even that is a conservative number), the Hercules II monoblock has more than enough power for any speaker, any space and any listening taste. It handles low-impedance speakers with ease, delivering 1.5 kW into 4 ohms and an incredible 2 kW into 2 ohms.
Balanced drive design for superior musicality
By using only N-type output transistors, instead of half N-type and half P-type as in other amplifiers, Hercules II achieves an essentially perfect balance between the positive and halves of the audio signal. As in a single-ended amplifier, the entirety of the audio signal passes through exactly the same type of output device.
Modular circuit concept
By building Hercules II from numerous 125-watt single-ended modules, we achieve the sound quality of a small amplifier with a full 1,000 watts of power.
Dual 3,000-watt power transformers
These custom-wound toroidal transformers contain several isolated sets of windings to supply independent power feeds to various circuits within the amplifier. Because the windings are isolated, the demands of one circuit do not affect the performance of other circuits, and consistent voltage and current are always supplied.
No Zobel network needed
Hercules II's inherently stable circuit design eliminates the need for a Zobel network at the output terminals to ensure stability at high frequencies.
Large heat sinks with high-flow ventilation ports
An amplifier of Hercules II's incredible power must have ample and consistent airflow for reliable operation. To ensure that the amplifier runs cool, we equip it with huge heat sinks and hundreds of large ventilation ports that minimize airflow impedance.
Line Stage Gain Module
In order to assure that all incoming signals are perfectly balanced and can thus benefit from Hercules II's balanced drive design, we gave it the same type of input stage we use on all of our line-level components. This fully complementary preamplifier circuit uses hand-selected FETs and servos to achieve an essentially perfect balance between the positive and negative halves of the signal.
Constellation Direct balanced interface
Because all Constellation Audio preamplifiers supply a perfectly balanced audio signal at their outputs, Hercules II includes the Constellation Direct input. This input bypasses the amplifier's Line Gain Stage Module, thus simplifying the audio signal chain and achieving maximum musicality.
Specifications
48.26 x 33 x 81.3 cm (whd)
Awards
Golden Ear Award 2016
"Constellation Audio took what was already the highest resolution and most transparent solid-state electronics I've heard... and vaulted them to a new level of performance in the Series II."
Jimmy Awards 2016
" Constellation Audio's Dream Team of designers consists of stars in the audio firmament. Among others, John Curl, Bascom King, Peter Madnick, and the late James Bongiorno have contributed to various aspects of Constellation product design. The legendary Irv Gross handles sales and marketing. "
The Absolute Sound - Editor's Choice 2016
Inspiration STEREO 1.0, Inspiration MONO 1.0, Inspiration PREAMP 1.0, Centaur Stereo, Argo, Perseus, Virgo III, Altair II, Hercules II Mono have been awarded the Absolute Sound 2015 Editor's Choice award.
Product of the Year Award 2015
Reference Series Altair II Preamplifier and Hercules II Amplifier have been awarded the Absolute Sound 2015 Product of the Year award.
Stereo Sound Grand Prix 2014 Winner
Stereo Sound Grand Prix 2014 Winners:
Hercules II Power Amplifier and Altair II Line Stage
Altair II
"A system that delivers such an incredible sound that you become lost within the music."
"One of the best preamplifiers existing today."
Hercules II
"A stunning performance level that outstrips the original."
"A product that will leave you yearning for it all the more."
The Absolute Sound - Editor's Choice Awards 2012
Editors' Choice 2012
Hercules and Altair have been awarded the Absolute Sound 2012 Editors' Choice award .
Absolute Sound 2011 - Product of the Year Award
Hercules and Altair have been awarded the Absolute Sound 2011 Product of the Year award.
Editors Choice Awards 2017
Editors Choice Awards from Issue #271 of TAS
Editors' Choice Award 2019
Constellation Audio received a number of Editors' Choice Awards for 2019 from The Absolute Sound.
TAS Editors Choice Awards 2020
The Absolute Sound granted a number of our components with their Editors Choice Award 2020, including:
Altair II. Argo. Centaur II, Hercules II/Hercules II Stereo, Inspiration 1.0, Inspiration Mono 1.0, Inspiration Preamp 1.0, Inspiration Stereo 1.0, Perseus, Andromeda, Pictor, Taurus Stereo, and Taurus Mono Amplifier.
The Absolute Sound Editors Choice Awards 2021
Constellation Audio won multiple awards this year in The Absolute Sounds Editors' Choice Awards 2021.
The Absolute Sound Editors Choice Awards 2022
Constellation Audio won multiple awards this year in The Absolute Sounds Editors' Choice Awards 2022.