Усилители мощности стерео — Soulution Audio 717 power amplifier

The 717 power amplifier is the stereo amplifier listed in the reference Series 7 line from Swiss manufacturer Soulution, presented at the Munich High End exhibition held from 9 to 12 May 2024 with series production expected to begin in Q4 2024. The Swiss price was announced as CHF 90,000. Soulution says the design was intended to drive every type of loudspeaker and to set new benchmarks for noise, phase error, common mode rejection and distortion.

Key specs that matter

Rated output is 2 x 150 W into 8 ohms, 2 x 300 W into 4 ohms and 2 x 600 W into 2 ohms, with pulse power above 2 x 6000 W. Bandwidth extends to 2 MHz at -3 dB, and phase deviation stays below 0.2 degrees at 20 kHz. THD+N is under 0.0001 percent at 100 W into 8 ohms from 20 Hz to 20 kHz. Signal-to-noise ratio exceeds 120 dB referenced to full 150 W output, spot noise is below -165 dBV per root hertz, and channel separation is better than 120 dB at 1 kHz. Damping factor tops 10,000, gain is +26 dB and continuous output current is limited to 32 A, while impulse current can pass 400 A.

Engineering and use context

The amplifier follows a fully dual mono layout, with each channel given its own printed circuit board. The input stage, shared with the 727 preamplifier, uses parallel instrumentation amplifiers with a 20 MHz bandwidth and feeds a voltage stage with more than 120 dB of loop gain and a highly linear feedback network. Sixteen power transistors per channel form the Class AB current stage. Four switched-mode supply modules, each rated 600 VA with an impulse rating of 2,100 VA, connect directly to the amplifier boards to keep contact resistance low and the path from supply to binding post short. The unit accepts mains of 100 to 240 V at 50 or 60 Hz, with draw under 0.5 W in standby, 300 W at idle and 1600 W at most. The case measures 480 x 350 x 505 mm and weighs about 50 kg.

Pairing

Input impedance at the two XLR sockets is 4.4 MOhm, and there is no single-ended input, so the preamplifier needs XLR outputs. One balanced XLR output is also provided. Besides stereo, the amplifier can be configured as a dual mono unit or as a bridged mono amplifier, which lets a second 717 be added later. Loudspeakers connect through gold-plated copper binding posts, two pairs per channel.

Alternatives

Within the Series 5 range, Soulution offers the 511 stereo amplifier as a two-channel power amplifier.