Technics SU-GX70EB Integrated Amplifier and Streamer

Technics SU-GX70EB integrated amplifier and streamer is designed to form the heart of a modern hi-fi system with streamed music content. This model features a powerful class D amplifier, providing 40 watts per channel into 8 Ohms – enough to drive most reasonably sized speakers.

The signal processing in this amplifier is always digital, reducing the chance of any noise getting into the signal. Another innovative feature is the Load Adaptive Phase Calibration feature. This is designed to ensure a perfect match between the amplifier and your speakers. Connectivity is also good, with a range of analogue and digital inputs as well as a phono input for a turntable.

Full digital amp with the JENO engine

The SU-GX70EB uses digital signal processing right up to the speakers. This makes it less susceptible to noise and interference. All the stages are digital from the input to the output. The JENO engine is also used for the HDMI ARC input, for the first time. This enables a TV sound connection to be made without any degradation caused by signal jitter.

Load Adaptive Phase Calibration

The impedance of a speaker changes with frequency, and an amplifier is required to give an even frequency response. However, Class D amplifiers use an output choke to remove the high frequency pulses. The choke is an inductor as is the speaker coil, this can cause unwanted phase and gain shifts, across the audio band.

As a result, Technics has developed a system that measures the actual sound with a microphone. The gain and phase are then adjusted to get a flat frequency response.

Twin, switch mode power supply

Twin power supplies are used for the SU-GX70EB. The design of the power supply is important, both for stability and noise performance. Especially for amplifiers with a mix of high gain and low gain circuits. As a result, the power supply has two sections. One drives the power amplifier and is independent of all the other circuits.

Additionally, there is a dedicated power supply for the high gain parts of the amplifier. The result should be less noise and a cleaner sound. The switching frequency is also higher than usual, further forcing any noise out of the audio band.

High quality TV audio through HDMI

HDMI connectors are used to feed the audio from a flat panel TV to an external device. The HDMI specification requires that a video signal be present before it will output audio. This has to be sent from the receiving amplifier, in this case, the SU-GX70EB.

However, this output can generate noise and interfere with the audio signal. As a result, the SU-GX70EB outputs a low rate video signal with all the pixels set to zero. This reduces the load on the transmitting/receiving circuits so less noise is generated. The signal path is also kept as short as possible.

Analogue inputs using discreet components

The analogue input circuit of the SU-GX70EB uses discreet components instead of I.C. Op-amps. This gives the best noise performance. Only the best audio grade components are used, as is is a dual mono design with independent circuits for each channel. Thin film resistors are used for accuracy and freedom from temperature drift. While film capacitors are used for the same reason. The result should be a detailed sound with no mush.

Good connectivity

The SU-GX70EB features a wide range of input options. Starting with analogue, there are two line level inputs as well as a phono input. All use RCA connectors. digital inputs include two optical and one coaxial input. There is also a USB input and a LAN ethernet port. Speaker connection is via two sets of gold plated binding posts. Finally, there are two sets of Wi-Fi aerials for a reliable streaming connection.