Усилители мощности стерео — Soulution Audio 511 stereo amplifier

The 511 stereo amplifier belongs to the Series 5 range of Swiss maker Soulution and borrows its amplification circuit from the older 711 and 701 amplifiers. The company describes the goal for this model as precision, stability and speed placed just a thin fraction behind its reference Series 7 designs. One chassis can be set to stereo, dual or mono operation, so a single unit can later become half of a bridged pair.

Key specs that matter

In stereo or dual mode the rating 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 2000 W. Set to mono, the unit delivers 600 W into 8 ohms, 1200 W into 4 ohms and 2000 W into 2 ohms, with pulse power beyond 4500 W. Gain is +26 dB in stereo and +32 dB in mono, while bandwidth reaches 800 kHz at -3 dB in stereo and 1.6 MHz in mono. THD+N stays below 0.001 percent at 50 W into 4 ohms across 20 Hz to 20 kHz, and intermodulation distortion is under 0.005 percent SMPTE and 0.0006 percent CCIR. Signal-to-noise ratio is 108 dB at 5 W, channel separation exceeds 120 dB at 1 kHz, and the stereo damping factor is above 10,000 against more than 5,000 in mono. Output current is limited to 45 A.

Engineering and use context

Soulution builds voltage gain from its own linearised amplifier circuits with a cut-off frequency of 80 MHz, and current gain is split over three stages, each working in a small, almost linear range. High Class A bias is held by precise idle current management and backed by 500,000 uF of storage capacitance. Ten power supplies feed the amplifier, with optocouplers isolating digital from audio circuits. Four switched-mode units deliver 2,400 W, filtered at input and output and followed by six linear low-noise regulators. Copper bars carry current across the board to the speaker terminals. Mains range is 100 to 240 V, idle draw is 100 W and maximum draw 1600 W in stereo, or 200 W and 2000 W in mono, and standby stays under 0.5 W. The case is 442 x 270 x 448 mm and weighs about 30 kg.

Pairing

Inputs are balanced XLR only, one per channel at 2 kOhm, with a ground-lift switch against hum loops. Bi-amping setups take the signal from XLR output sockets to a further amplifier, and a front mute key disconnects all inputs at once. LINK-IN accepts a turn-on signal from a Soulution preamplifier, and RS-232 control and a service port for firmware updates are fitted.

Alternatives

The Soulution 717 power amplifier is the stereo model from the reference Series 7 line.