Reference-class High-quality Audio Technology
Inheriting the reference-class audio technology concept, the JENO Engine transmits and processes audio signals in full digital and with minimal jitter from the input stage to the power stage. Speaker load adaptive phase calibration (LAPC) ensures ideal gain and phase characteristics for any type of speaker. The newly developed low-distortion switching power supply realises accurate power supply by suppressing switching frequency fluctuations caused by load shifting.
JENO Engine (Jitter Elimination and Noise-shaping Optimization)
In order to faithfully transmit the massive amount of audio data sent to the speakers without loss, the SU-G700 power amp section uses full digital amplification employing the JENO Engine, based on the design concept of reference systems. In order to solve the issue of sound quality degradation due to jitter, which poses problems for conventional digital amplifiers, the SU-G700 has an original jitter reduction circuit that eliminates jitter over the entire audible frequency range. Also, a unique, high-precision PWM (Pulse Width Modulation) conversion circuit is used for PWM conversion, which is important for sound quality. By optimising items such as the noise-shaping speed, degree, and quantization number through our unique expertise, data even in the wide dynamic range contained in high-resolution sound sources is converted to PWM signals without loss. These technologies provide reproduction of natural and finely detailed sound, enabling perception even of delicate music nuances.
LAPC (Load Adaptive Phase Calibration)
Speaker impedance changes with each frequency and a power amplifier is required to drive speakers without being affected by the speaker’s characteristics. However, conventional digital amplifiers are connected to speakers through a low-pass filter at the output stage, so they are even more strongly affected by the speaker impedance characteristics. Also, although the amplitude characteristics of conventional amplifiers due to negative feedback were improved, the phase characteristics could not be enhanced. We thus developed a speaker impedance adaptive optimisation algorithm that performs correction to the ideal impulse response through digital signal processing by measuring the frequency amplitude-phase characteristics of the amplifier with the speakers connected. This new technique enables flattening the frequency characteristics of amplitude and phase, which had previously not been achieved by amplifiers, as well as delivering a sound with rich spatial expression.
Low-noise PHONO Input
PHONO MC input is now supported. The PHONO input achieves low noise by using a differential parallel connection configuration of a first-stage, low-noise FET. In addition, four-level gain adjustment enables selection of the best gain according to the cartridge output. This enables optimal playback of high-grade analogue recorded sound sources tailored to the user’s environment.
Class AA Headphone Amplifier
The SU-G700M2 uses a Class AA headphone amplifier with separate amplifier circuits for voltage amplification and current amplification of the audio signal. The voltage is amplified by a high-grade operational amplifier, the current is amplified by an operational amplifier with high current-supply capability, and the high-grade PWM signal output from the JENO Engine is converted to analogue with high precision, thus enabling headphones to be ideally driven. This makes it possible to reproduce music with low distortion and a wide frequency range no matter what the load impedance of the headphones is.