The Technics SU-G700M2 appears to be a less powerful, less–well-equipped sibling of the Technics SU-R1000 integrated amplifier that KM reviewed in December 2021, which offered superb measured performance.1 I measured the SU-G700M2 with my Audio Precision SYS2722 system,2 and as the amplifier has an output stage that resembles class-D, I inserted an Audio Precision AUX-0025 passive low-pass filter between the test load and the analyzer. This filter reduces RF noise that would otherwise drive the SYS2722’s input circuitry into slew-rate limiting. (Without the filter, there was 720mV of ultrasonic noise, with a center frequency of 67kHz, at the amplifier’s output terminals.) I used the filter for all the loudspeaker output tests, other than frequency response.
I looked first at the Technics’s performance via its single-ended line inputs. The SU-G700M2 preserved absolute polarity at all outputs with Phase set to Normal. The volume control operated in accurate 0.5dB steps, and the maximum gain at the loudspeaker outputs was 42dB. (The optional 20dB attenuation was bypassed for this measurement.) At the preamplifier output, the gain was 21.3dB, and at the headphone output it was 26.7dB. The SU-G700M2’s power amplifier stage can be accessed separately: It offered a fixed gain of 32.4dB. The input impedance at both the line inputs and the power amplifier
