The MAX is based on a proprietary circuit Audionet calls its Ultra-Linear Amplifier (ULA) topology, pioneered and developed from its early medical amplifier applications. Much like the PRE G2, the MAX is magnetically and capacitively optimized to largely eliminate feedback from electrical interference, as well as from reciprocal influences between the amplification channels during the amplification process. To optimize speed and high-frequency attributes, to use its own words, Audionet “indulges in an orgy of minimalization.” Furthermore, the MAX does not use any sonically detrimental components such as coils, chokes, or power relays in the signal path.
The input stage is configured as a cascaded and bootstrapped differential amplifier using a low-noise, monolithic dual FET, with the input and driving stages separately powered by oversized 80VA toroid-core transformers with separate windings for positive and negative operating voltage. The output stage is equipped with eight hand-selected, actively biased power MOSFETs and is stabilized with discrete MOSFET regulators, again with the negative and positive operating voltage decoupled entirely. Two individual 1000VA toroid-core transformers feed the positive and the negative half-cycles of the mains, and four fast, impulse-resistant, high-current capacitors (with a total filtering capacity amounting to 156,000µF) serve as a reservoir.
It will likely come as no surprise that during the manufacturing process of every MAX, all the relevant components are repeatedly tested, meticulously measured, and then matched in optimal pairs to assure best performance.
Again, much like the PRE G2, a microprocessor controls all functionality including display brightness, input selection, auto on and off, and auto-start options, as well as constantly monitoring for the presence of DC, high frequency, temperature, and overload conditions. In the case of a fault, the MAX disconnects from the mains supply and its two-line display indicates fault source(s) in plain text. The display can use either a “screen saver,” randomly moving its selected display (input selected or temperature) every 12 seconds or so, or just be switched off.
Both the PRE G2 and the MAX circuits are populated with only the finest components available, many of which are custom-made for Audionet. Select filter capacitors and the bulk of the audio-grade electrolytic capacitors employed use a dielectric made of silk. They also use mica capacitors, selected high-voltage foil capacitors, the best connector systems available from Furutech, including rhodium-plated loudspeaker outputs, and silver-gold alloy internal wiring. Even the fuses in the MAX are made of rhodium and gold! And, both units, like all the Audionet machines, are available with a brushed-aluminum front panel, either silver or anodized black, and with your choice of either red or blue display.
While I’ve never been one to take performance statistics as an end-all for sonic performance, I must say that when I looked at the published frequency response of the PRE 2G, which is given as 0Hz–2MHz (-3dB), DC-coupled, I admit to being impressed.
The MAX’s rated output is 400 watts into 8 ohms, 700 watts into 4 ohms, and 1100 watts into 2 ohms. And like the PRE G2, the MAXs stated bandwidth of 0–500kHz at -3dB is superb. With a claimed damping factor of 1800 at 10kHz, and a stunning 10,000 at 100Hz, the MAX should have the ability to control any loudspeaker you choose.