SU-G700
Zintegrowany wzmacniacz stereo
London, 4 January 2017 – Technics has today unveiled the new Grand Class SU-G700 Stereo Integrated Amplifier, featuring the JENO Engine (Jitter Elimination and Noise-shaping Optimisation), LAPC (Load Adaptive Phase Calibration), and reference-class audio technology concept for high-purity sound reproduction.
In order to faithfully transmit the large amount of audio data included in content to the speakers without loss, the SU-G700 power amp section uses full digital amplification including a JENO Engine, following the design concept of Technics reference systems.
To solve the issue of sound quality degradation due to jitter, which often poses problems to conventional digital amplifiers, the SU-G700 has an original jitter reduction circuit, which eliminates jitter over the entire audible frequency range. Also, a unique, high-precision PWM conversion circuit is used for PWM conversion, which is important for achieving premium sound quality. By optimising items such as the noise-shaping speed, degree, and quantisation number through Technics’ unique expertise, data contained by high-resolution sound sources is converted to PWM signals without loss – even in the wide dynamic range.
These technologies provide the reproduction of natural and finely detailed sound, enabling listeners to perceive even delicate nuances of music.
Speaker impedance changes with each frequency, requiring a power amplifier to drive speakers without being affected by their characteristics. However, conventional digital amplifiers were connected to speakers through a low-pass filter at the output stage, making them even more strongly affected by the speaker impedance characteristics.
Also, while the amplitude characteristics of conventional amplifiers could be improved due to negative feedback, phase characteristics could not be enhanced. To solve this problem, Technics developed a speaker impedance adaptive optimisation algorithm that corrects 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 other amplifiers have not achieved previously, as well as delivering a sound with a rich spatial expression.
With a conventional switch mode power supply, the switching frequency changes in response to the load fluctuation in order to control the switching ON time for stabilising the output voltage. This fluctuation component in the switching frequency has a negative impact on sound quality.
The SU-G700’s newly developed power supply reduces the noise component harmful to sound quality by fixing the switching frequency. In addition, the latter stage in the switching power supply is provided with a linear regulator to stabilise the output voltage. The linear regulator uses custom, high-definition electrolytic capacitors.
What's more, Technics’ current resonance-type power supply decreases the level of switching noise. The parts used for absorbing noise, such as capacitors, were carefully selected. All possible measures were taken to achieve low noise and reproduce clear sound.
In integrated amplifiers, there are a variety of circuits, for example handling micro-signals of inputs or large current, such as output circuits and power-supply circuits. The SU-G700 uses a three-section construction with partitions installed between the circuit blocks according to the signal level handled. This eliminates interference between circuit blocks, thus achieving clear sound quality.
Also, the chassis rigidity due to this construction suppresses the vibration of electrical parts, thereby suppressing deterioration in sound quality.
The High-Rigidity Metal Double Chassis features a steel-plate inner chassis and a steel-plate outer chassis to reduce vibration and noise that degrade the purity of sound.
To support heavy parts and components, and to achieve improved stability, the inner chassis is made of a 1.2mm plate. The bottom surface of the cabinet consists of a 2mm steel plate. This improves the vibration-damping performance and achieves a low center of gravity. The front panel is made of a 7mm aluminum plate to resist the effects of electromagnetic noise.
The two large needle meters provided on the front express the dynamism of the music. The volume knob uses pure aluminum and achieves an excellent feeling.
