KSA-i400

About the KSA-i400

The Krell KSA-i400 is an absolute reference stereo power amplifier that operates in pure Class A up to its full rated power of 400 watts into 8 ohms, utilizing Krell's proprietary iBias technology to maintain Class A operation efficiently without excessive heat. It features XD technology to reduce output impedance for superior speaker control and Sym-Max circuitry to minimize 2nd order harmonic distortion, enhancing soundstage and naturalness. The amplifier uses a fully balanced, DC-coupled circuit topology with high-quality components, including 16 pairs of high-power audio transistors and 8 pairs of driver transistors. Its massive power supply includes 5400 VA transformers and 188,000 µF of filtering capacitance, enabling it to deliver 400W RMS into 8 ohms, 800W into 4 ohms, 1600W into 2 ohms, and drive 1 ohm loads with peak current up to 62 amps. The KSA-i400 offers a frequency response of 20 Hz to 20 kHz (+0.1 dB, -0.07 dB), a damping factor greater than 800 at 8 ohms, a signal-to-noise ratio above 117 dB, and a gain of 26.4 dB. It includes balanced XLR and unbalanced RCA inputs, an Ethernet RJ45 port for control and monitoring, and a 12V trigger input for integration with home automation. The amplifier weighs approximately 73 kg and measures 438 x 239 x 610 mm (W x H x D). It is praised for its organic, spacious, and detailed musical presentation with robust low-end and dynamic capabilities, making it a flagship model in Krell's lineup.