About the Eclipse Mono Amplifier
The description here of the Eclipse mono amps sort of follows on directly from the description of the stereo amp, as they share so much of the fundamental DNA. As monoblocs output power is obviously up, at 550W into 4Ohms here, versus 350 into 4 Ohms for the stereo version. And there are measurable differences too of course; THD at 1kHz is 0.00001% for the monos, whereas the stereo amp is 0.00003%.
But let's get to sound quality. If the Halcro's float your boat as a concept (as opposed to valve exotica for example), and you need to be working up at this level of driving capability, there is nothing else that quite compares to the Halcro pair. Transparency, detail and tonality are chrystalline in their characteristic, resolving vocal and instrumental timbre in a form that sounds so much like real voices and real instuments that the first time you hear it you sit there in disbelief. And when things get going, musical propulsion, dynamics and drama are also a vastly different experience, backed up by the lowest noise floor imaginable and a soundstage that is so defined and stable that you find yourself stunned for a second time.
Lots of fancy words (and we're used to seeing these sorts of acolades all the time), so really we can only say one thing – these are incredibly important amplifiers to hear. Check these links out for some important reviews; Audio Esoerica Review, Australian Hi-Fi.
Tech Insight
We discussed the chassis construction and input and output EMI filtering when discribing the stereo amplifier. And of course in the monos, these features remain. But another significant element in both Halcro amps is the unusual, dual, cascade power supply. This dual system uses a Power Factor Corrected first stage that matches it's demand to the voltage and current waveform of the mains – hence the draw of the power is optimised in a way that significantly increases efficiency and reduces distortion. The second stage then buffers and optimises the generation of the required DC Voltages for the amplifier stages. Halcro then also point to highly optimised local regulation using carefully selected components based on final listening results, but do not go any further in revealing the exact designs and specifications.
Specifications
Power
Power output into 4 ohms resistive > 500 W
Power output into 8 ohms resistive > 280 W
Distortion
At full power output, all harmonic distortion orders:
THD <-120 dB (<300 parts per billion) up to 20 kHz (100 kHz B.W.) at 450 W into 4 ohms.
THD @ 1 kHz <-134 dB (<200 parts per billion).
For sum of 19 and 20 kHz tones, each delivering 112.5 W into 4 ohms = peak power 450W, resulting intermodulation products each <-120 dB relative to output.
SMPTE-IM intermodulation products each
<-120 dB relative to output.
Inputs
There are four input modes:
an unbalanced voltage mode input with an impedance of 22 kOhms
a balanced voltage mode input with an impedance of 22 kOhms + 22 kOhms
a current-mode input with a 60 Ohm input impedance (infinite impedance current source)
a minimal path voltage mode with an input impedance of 660 Ohms
The voltage gain of the balanced and unbalanced inputs is 30 V/V and for the minimal path mode is 15 V/V. The gain of the current mode is 9 V/mA
Noise
The equivalent input noise at the input is 5 nV/sqrt(Hz) for the voltage modes and 6 pA/sqrt(Hz) for the current mode.
Frequency Response
3Hz – 215kHz: -3db (@1W)
7Hz – 90kHz: -1dB (@1W)
Dimensions (per monoblock)
Weight, 62kg
Height, 79cm
Width, 40cm
Depth, 40cm
Total shipping weight, (one pair including pallet), 180kg
Matching & Setup
The Eclipse mono amps are, in physical form, identical to the stereo amp with the same brilliant casework that makes the machine, in essence, it's own low-microphony rack. So a system would probably be setup with source components and preamp on a good rack, and the Eclipse monos positioned perhaps either side of the rack or much closer to the speakers in a long interconnect/short speaker lead arrangement.
Of course with even more power available, the monos are going to thrive with big speakers in a big room. But they should not be thought of as 'muscle amps' because that would be missing the point – these are refined precision instruments that reward the highest quality throughout a system, great setup and attention to detail. Then they will present music of every scale that will just arrive in front of you with seemingly no characteristics of a hi-fi system whatsoever.
