Technics Introduces Reference Class SU-R1000 Integrated Amplifier Leveraging Low-Resistance GaN Devices

September 3 2020, 01:55
In the midst of a busy week for new audio products in all market segments, Technics unveiled the SU-R1000, its first Reference Class integrated amplifier. As Technics explains, its Reference Class products are developed in pursue of the brand's insatiable desire to deliver ultimate sound quality to customers, and offer the premium musical experience the Technics brand is known for. The SU-R1000 follows design references of the classic hifi components from decades ago. But inside, this is a technical evolution of the brand's 2014 rebirth.

The SE-R1, Technics' first Reference Class stereo power amplifier introduced in 2014, featured many new and original digital technologies such as LAPC (Load Adaptive Phase Calibration) for achieving ideal impulse response and JENO (Jitter Elimination and Noise-Shaping Optimization) Engine for high-quality, high-precision PWM signal conversion with minimum jitter. Boasting precise sound image and expansive sound ambience, the SE-R1 was received with open arms by the market and signaled the acceptance of digital amplifiers by the high end audio community. 

Later on, the SL-1000R turntable system released in 2018 fused digital control technology with traditional analog technology at high levels. Combined with the overwhelmingly powerful torque and accurate and smooth rotation performance, the turntable realized unprecedented quietness and sound dynamism unattained by any conventional record player.

Armed with the achievements and evaluations accumulated in the hifi market since the rebirth of the Technics brand in 2014 and backed by the results of R&D aimed at improving sound quality focussing upon digital technology, Technics now launches the SU-R1000 integrated amplifier, further evolving digital amps to new heights.

Given that today's mainstream music sources are digital, such as CD and streaming platforms, digital signals should ideally be processed in the original digital format. Furthermore, devices such as AD converters are also advancing, allowing high-precision digital signal processing of analog music sources. Under such circumstances, Technics has been devoted to the development of digital technology since 2014. 

In creating the SU-R1000 Reference Class product, Technics leverages the newly developed Active Distortion Cancelling Technology (ADCT), in addition to the proprietary technologies that maximize digital amps' advantages, such as LAPC and JENO. The ADCT realizes further enrichment of sound quality by eliminating distortion generated in the power stage by speaker's counter electromotive force and power supply voltage drop.

The new switching power supply system, Advanced Speed Silent Power Supply, has successfully improved the S/N ratio. Furthermore, four independent power supply units provided for different circuit blocks realize superb separation and dynamic sound reproduction. What's more, the power devices incorporate Panasonic's new low-resistance GaN (gallium nitride) devices.

For enthusiasts of vinyl, the SU-R1000 is equipped with an Intelligent Phono EQ, which utilizes digital technology to achieve an accurate equalizer curve and deliver high sound quality by improving the crosstalk of the cartridge and enhancing the frequency characteristic determined by the matching of the cartridge and phono equalizer. The Intelligent Phono EQ mounted in the SU-R1000 uses DSP, perfected through the development of LAPC, in order to realize what was not possible with analog Phono-EQ. This technology consists of three parts: 1. Accurate EQ Curve, 2. Crosstalk Canceller and 3. Response Optimizer. These functions can be turned ON/OFF to suit the user's preference.

Jitter Elimination and Noise-Shaping Optimization (JENO)
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 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.

Load Adaptive Phase Calibration (LAPC)
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 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.

Active Distortion Cancelling Technology (ADCT)
The Active Distortion Cancelling Technology newly developed by Technics extracts and removes distortion in the power output stage which is generated by the speaker's counter electromotive force and voltage drops. In the hifi audio market where an unlimited number of audio systems can be configured by combining various products, high-end audio amplifiers need to drive a diversity of speakers to the fullest. The Active Distortion Cancelling Technology accurately extracts distortion by determining the difference between the speaker terminal output and JENO output and then applies 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 ambience, regardless of the types of connected speakers.

More Design Details
The SU-R1000 uses a switching power supply system to ensure stable supply of voltage and current required by the digital amp. In a conventional switching power supply system, the ON time of the switching operation was controlled in order to stabilize the voltage, and this caused the switching frequency to fluctuate according to the load, resulting in a modulation noise to affect the sound quality. 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 component into high frequencies. The result is 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 the important operation timing information, is the key to high sound quality. However, power supply noise from the clock circuit is a major impeding factor. The SU-R1000 is equipped with a Battery Driven Clock Generator. The use of a battery as a power supply for the clock circuit eliminates the adverse effect of power supply noise on the clock signal, thus enabling superb sound image localization and clear sound space expression.

GaN-FET Driver (High Speed and Low Impedance Power devices)
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 new amp 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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