KST-150

About the KST-150

The Luminance Audio KST-150 is a stereo power amplifier rated at 150 watts per channel into 8 ohms and 250 watts into 4 ohms. It features a balanced, cascade-based, 3-stage design with a high common mode rejection ratio of over 90 dB. The amplifier is engineered for extremely high speed with a slew rate of 250 volts per microsecond, far exceeding the industry norm of around 40 V/µs, enabling it to accurately reproduce complex musical passages. It has an ultra-wide bandwidth from DC to 630,000 Hz, allowing it to reproduce harmonics well beyond the audible range for enhanced tonal realism. The KST-150 is DC coupled at the input with no blocking capacitor, ensuring perfect square wave response at low frequencies and excellent bass definition. It maintains a high damping factor of 100 across the audible frequency range, providing tight control over speaker drivers. The power supply uses a 700VA IU core transformer with a large 54,000 µF capacitor bank, delivering dynamic headroom capable of 300 watts per channel for short bursts. The amplifier is unconditionally stable into reactive loads, suitable for driving electrostatic speakers. Sonically, it is described as quick, airy, highly resolved, natural sounding with detailed midrange, true bass, and a three-dimensional soundstage. The KST-150 was designed by Steve Keiser, known for the legendary B&K ST-140 amplifier, and is It is highly regarded for its speed, clarity, and musicality, making it a benchmark in high-end audio amplification.