Jitter is a major cause of distortion in digital systems and is caused by mis-timing in the master clocks used in digital-to-analog conversion. To eliminate the degradation of sound caused by jitter, Technics has developed an original jitter reduction circuit, comprising a clock generator in the noise-shaping system to reduce jitter in the low-frequency range and a high-precision sample rate converter for suppressing jitter in the high-frequency range. Thus it reduces jitter in an ideal way over the entire frequency range. This works with the original high-precision PWM (Pulse Width Modulation) conversion circuit, optimizing the noise-shaping speed, the degree, and re-quantization number, and the PWM gradation, in order to convert high-resolution signals to PWM without causing any damage to the dynamic range. These technologies enable Technics digital amplifier designs to reproduce the natural and delicate nuances of music.
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 affected by the speaker impedance characteristics. Technics developed a speaker impedance adaptive optimization 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.
The Active Distortion Cancelling Technology newly developed by Technics accurately extracts and removes distortion in the power output stage which is generated by the speaker’s counter electromotive force and voltage drops. The Active Distortion Cancelling Technology accurately extracts distortion by determining the difference between the speaker terminal output and JENO output and then applies a correction to the output digital signal, thus correcting the conventional digital amp system. This provides powerful speaker driving force and acoustic energy while offering the superior features of the digital amp, such as low noise, sharp sound image, and expansive sound ambiance, regardless of the types of connected speakers.
The SU-R1000 uses a switching power supply system to ensure a stable supply of voltage and current required by the digital amp. The Advanced Speed Silent Power Supply has eliminated this noise by fixing the switching frequency in the 400-kHz band. Furthermore, a Super Low Noise Regulator is provided in the later stage. This prevents the decrease of regulation resulting from the fixed switching frequency and impedes the mixing of noise components into high frequencies. The result is a high-response power supply that brings out the best performance from the digital amplifier.
In the SU-R1000, every element comprising the power supply has been revamped for higher sound quality. What’s more, four independent power supply units are provided for different circuit blocks for further enhancement of sound quality. Since the SU-R1000 is an integrated amplifier, the internal circuits consist of a pre-amp stage and power amp stage in a mix of analog and digital circuits. The Phono-EQ section which processes minute analog signals is particularly susceptible to the effect of noise transmitted through the power supply line. The SU-R1000 uses separate power supply units for the analog circuits and digital circuits in the pre-amp stage. It also uses separate power supply units for the right and left channels in the power amp stage that requires large electrical power. With the four independent power supply units, the SU-R1000 prevents power-line-induced interference among the circuit blocks and realizes a high S/N ratio and superb separation.
For a digital amplifier, improving the precision of the clock, which provides important operation timing information, is the key to high sound quality. The SU-R1000 is equipped with a Battery Driven Clock Generator, which eliminates the adverse effect of power supply noise on the clock signal, thus enabling superb sound image localization and clear sound space expression.
In the power output section of the amplifier, Technics has employed a high-speed GaN (gallium nitride) FET driver device with super-low resistance. This enables the construction of a high-power amp using a single push-pull configuration, allowing the length of the large current carrying signal path to be shortened, and resulting in outstanding linearity regardless of the sound level.
The Intelligent Phono EQ mounted in the SU-R1000 utilizes the sound quality improvement technology for DSP, which Technics has accumulated through the development of LAPC, in order to realize high sound quality not possible with analog Phono-EQ. This technology consists of three parts: Accurate EQ Curve, Crosstalk Canceller, and Response Optimiser. These functions can be turned ON/OFF to suit the user’s preference.
The SU-R1000 comes with an abundance of input and output terminals, including Phono XLR Input and two USB-B Input terminals, to handle a broad range of analog and digital audio sources and peripheral equipment.
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