Koru Phono

About the Koru Phono

The Plinius Koru is a high-end solid-state phono preamplifier designed for serious vinyl systems using both low-output moving coil and higher-output moving magnet cartridges. It uses a distinctive two-in-one chassis that physically separates the power supply from the amplification circuitry to reduce interference and noise. The power supply employs a virtual battery approach with over 100,000µF of filter capacitance and sophisticated two-stage regulation, providing a low-impedance, stable supply for the audio stages. The amplification and equalisation circuitry use high-quality, long-life components for accuracy and reliability, with passive high-frequency and active low-frequency RIAA equalisation to maintain stability and finesse. User adjustments on the rear panel include gain settings of 50dB, 56dB, 60dB and 66dB, load impedance options from 22 ohms up to 47k ohms (22, 47, 100, 220, 470, 1k, 22k, 47k ohms), and input capacitance selectable between 100pF and 570pF. The Koru provides an RCA unbalanced input and both RCA unbalanced and balanced XLR outputs for flexible system integration. Typical distortion is less than 0.01% THD at all levels below clipping, with a signal-to-noise ratio of around -80dB A-weighted at 5mV input. Power consumption is about 10W in use and approximately 7W in idle/standby. The chassis is full-width at 450mm, about 80-90mm high, and 400mm deep, with weight around 5.5-7kg depending on source specification.