JENO Engine Amplifier (Distortion suppression and noise-shaping optimization)
To deliver large volumes of audio data to speakers with precision and no loss, the SU-G700M2's power amplifier section employs a fully digital amplification architecture built around the JENO Engine, inspired by reference-class system design. To combat the jitter that commonly degrades conventional digital amplifiers, the unit incorporates a sophisticated jitter-reduction circuit that operates across the entire audible band. A proprietary, high-precision PWM (Pulse Width Modulation) conversion stage—tuned through careful optimization of noise-shaping rates, quantization step counts and levels, and other parameters honed from our experience—converts high-resolution audio, even with wide dynamic range, into lossless PWM signals. The result is natural, highly detailed reproduction that preserves subtle musical nuance.
LAPC (Load Based Phase Calibration)
Because speaker impedance changes with frequency, amplifiers must drive a load that varies depending on the speaker. Conventional digital amplifiers, however, are affected by the speaker when their output passes through an output low-pass filter, and while negative feedback can flatten amplitude, it does little to correct phase behavior. To address this we developed an adaptive speaker-impedance optimization algorithm that measures the combined frequency, amplitude and phase response with the speakers connected and applies DSP-based correction to approach an ideal impulse response. This smoothing of amplitude and phase responses yields a more coherent, spacious soundstage previously difficult to achieve with standard amplifier designs.
Advanced Speed Silent Power Supply
Leveraging the power-design techniques developed for the SU-R1000 reference model, the SU-G700M2 improves speaker drive authority and energetic response. To stabilize voltage and current while minimizing modulation noise that can color the audio, switching frequency has been raised from the typical ~100 kHz region to the ~400 kHz range. The high-speed switching stage uses the same gallium-arsenide (GaN) FETs and silicon-carbide Schottky diodes (SiC SBD) applied in the SU-R1000 to maximize efficiency and responsiveness.
The final supply stage includes an ultra-low-noise regulator to prevent degradation tied to a fixed PWM switching frequency and to keep switching noise out of the high audio band. Together these measures produce a quiet, high-performance power supply that lets the digital amplifier realize its full sonic potential.
Three-section configuration
Integrated amplifiers contain circuits ranging from micro-signal inputs to high-current outputs and power stages. The SU-G700M2 separates these into three distinct sections with baffles placed between circuit blocks according to the signal level handled, preventing mutual interference and preserving signal purity. In addition to the three-section layout, the chassis features a double-layer steel construction (1.2mm and 2mm plates), a 1.6mm steel top panel and a 7mm aluminum front panel to provide effective vibration damping.
Low noise PHONO input
PHONO MC support is provided. The PHONO input achieves very low noise by using a differential parallel configuration of a low-noise first-stage FET. Four gain settings allow selection of the optimal amplification to match the cartridge output, ensuring faithful playback of high-quality analog recordings in a variety of user systems.
AA headphone amplifier
The SU-G700M2 includes a class AA headphone amplifier that separates voltage and current stages for the best sonic performance. Voltage is handled by a high-quality op amp while current drive is supplied by a high-current op amp; the precise conversion of the JENO Engine's high-quality PWM output to analog lets the amplifier deliver strong, low-distortion drive across a wide frequency range regardless of headphone impedance.
