Performer S900

The SPL Performer S900 is a stereo power amplifier with an output of 2 x 370 W (4 Ω), 2 x 420 W (2 Ω) and 2 x 200 W (8 Ω). It is designed for high-resolution loudspeakers that do not require excessive power, with sufficient reserves to drive loudspeakers of any size. The compact amplifier uses SPL VOLTAiR technology and separate amplification stages for voltage and power, supporting the operation of its class-AB circuit.

VOLTAiR technology allows the Performer S900 to process higher signal levels while keeping its components away from critical operating ranges. Each amplification stage has its own negative feedback path, preventing feedback from the loudspeaker from interacting with the input stage. SPL states that this arrangement produces a natural, relaxed and detailed sound without listening fatigue.

The amplifier is available in black, red or silver, matching the SPL Professional Fidelity HiFi product line. Many components are fitted using Through-hole technology, allowing SPL to select components on the basis of their sound. The design process combines circuit development with listening.

Analogue connectivity is provided by a stereo pair of XLR inputs and a stereo pair of RCA inputs, allowing connection to preamplifiers without adapters. The input is selected using the Input Select switch on the rear panel.

Input sensitivity can be adjusted in 0.5 dB steps from 0 dB to -5.5 dB. This trim switch allows the operating range of the loudspeakers and preamplifier to be matched without using a panorama potentiometer in the preamplifier.

The loudspeaker binding posts accept banana plugs and stranded speaker cable up to 4 mm in diameter. SPL does not recommend connecting loudspeakers with an impedance below 2 ohms.

The VOLTAiR circuit operates at a DC voltage of 120 volts, which is four times the voltage used by IC-based semiconductor op-amps. SPL describes its 120V technology as its reference technology and uses the VOLTAiR name for it in the Professional Fidelity series.