Constellation Altair II Linestage and Hercules II Monoblock Power Amplifiers

A Landmark Refined

Equipment report
Solid-state power amplifiers,
Solid-state preamplifiers
Constellation Altair II,
Constellation Hercules II
Constellation Altair II Linestage and Hercules II Monoblock Power Amplifiers

I mentioned this in my original review, but it bears further discussion here. The Hercules II doesn’t sound like an 1100W amplifier. It’s not that it doesn’t sound powerful or has trouble driving loudspeakers. The Hercules II is a powerhouse, reproducing the most demanding bass dynamics with completely effortless grace and authority. When I say that the Hercules II doesn’t sound like an 1100W amplifier, I mean that as a compliment. Many high-power “dreadnought” amplifiers can sound hard and artificial, a character perhaps introduced because the transistors in the output stage all exhibit slightly different operating characteristics. The more transistors in the output stage, the greater the potential for the individual transistors not to work together in unison. There are many examples of an amplifier line in which the amplifiers are identical to each other except for the number of output transistors (along with the size of the power supply and heatsinks). The lower-powered amplifiers always sound better, the most famous example being the Adcom GFA-535 (60Wpc), GFA-545 (100Wpc), and GFA-555 (200Wpc). Cognoscenti knew that the GFA-535 was the sweetest-sounding of the line. Despite an output stage of 64 MOSFETs, the Hercules II is capable of the delicacy and finesse of a low-powered unit, yet can deliver seemingly unrestricted dynamics with grace and ease.

Finally, I should note that the Hercules II takes a very long time to sound its best. The treble purity and resolution are apparent within half an hour or so, but after about four hours the amplifier really opens up, with a greater sense of space and an overall increase in ease and relaxation.

The Constellation Audio Altair linestage and Hercules monoblock amplifiers in their updated version maintain their status as world-class references. They are a convergence of beautiful design and build-quality, practically unlimited power delivery, and, most importantly, state-of-the-art sound. Yes, these electronics are priced in the stratosphere—better than a quarter of a million dollars. That number is breathtaking, but then again so is the performance. If there are electronics that are more resolving and transparent, or that have a cleaner and more filigreed treble, I haven’t heard them.

I concluded my review of the original Altair and Hercules by writing that these electronics have “established a benchmark against which all other linestages and power amplifiers can be compared.” Nearly five years and one update later, along with extensive experience with reference-grade.


Altair II Linestage
Inputs: Four balanced on XLR jacks, four unbalanced on RCA jacks
Outputs: Two balanced on XLR jacks, two unbalanced on RCA jacks (both main outputs); one record output on XLR jacks, one record output on RCA jacks
Input impedance: 200k ohms balanced, 400k ohms unbalanced
Output impedance: <50 ohms
Volume control resolution: 0.1dB, 0.5dB, 1dB (level-dependent)
Weight: 84 lbs. (linestage), 26.2 lbs. (power supply)
Dimensions: 17.5" x 5.53" x 14.82" (linestage); 17.5" x 2.82" x 14.5" (power supply)
Price: $80,000

DC Filter for Altair II
Dimensions: 17.5" x 2.82" x 14.5"
Price: $9000

Hercules II Power Amplifier
Output power: 1100W into 8 ohms, 1500W into 4 ohms, 2000W into 2 ohms (1kHz, 1%THD)
Gain: 32dB
Input impedance: 100k ohms unbalanced, 200k ohms balanced
Output impedance: 0.05 ohms
Inputs: Two balanced on XLR, one unbalanced on RCA
Dimensions: 19" x 13" x 32"
Weight: 220 lbs. each, net
Price: $180,000/pr.

3533 Old Conejo Road
Suite 107
Newbury Park, CA 91320
(805) 201-2610        

Associated Equipment
Digital front end:
Aurender W20 music server, Berkeley Alpha Reference DAC, Berkeley Alpha USB converter
Analog front end: Basis Inspiration turntable with Basis Vector IV and Superarm 9 tonearms, Air Tight PC-1 Supreme cartridge, Moon by Simaudio 810LP phonostage
Support: Critical Mass Systems Maxxum equipment racks (x2), Maxxum amplifier stands (x2)
Cables: MIT Oracle MA-X and Oracle SHD, AudioQuest Wild Digital AES/EBU, WireWorld Platinum Starlight USB
AC: Four dedicated 20A AC lines; Shunyata Triton 2, Triton DP, Typhon (x3) conditioners, Shunyata Sigma power cords
Acoustics: ASC 16" Full-Round Tube Traps, ASC Tower Trap, Stillpoints Aperture Panels
Accessories: Klaudio ultrasonic record cleaner; Shunyata cable lifters, Critical Mass Systems Rize isolation

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