HPLSD 500

About the HPLSD 500

The Helixir Audio HPLSD 500 is a reference power amplifier designed with a pure Class A shunt power supply and an ultra-low noise voltage gain control loop of 120dB. It features a large quantity of capacitors and an optimized design with small island masses, providing an energy margin ten times greater than equivalent analog systems. The amplifier is built in a strict dual mono configuration with two independent and isolated power supplies, which significantly improves sound depth and soundstage by avoiding ground returns through interconnect cables. It incorporates the proprietary "Extrem Bass Control System," an intelligent loop device that provides full control over loudspeaker diaphragm movement, ensuring accurate, energetic, and detailed sound reproduction across a wide range of speaker types, including bass reflex, sealed box, and electrostatic speakers with impedances close to 1 ohm. The HPLSD 500 delivers a warm timbre reminiscent of tube amplifiers combined with exceptional speed and clarity, capable of reproducing cymbals at full power with remarkable ease. Its distortion rate is theoretically immeasurable at -166dB, allowing exceptional transparency in music reproduction. The amplifier also features digital processor control that monitors amplifier blocks in real time, ensuring thermal regulation and protection against current, voltage, and thermal faults. It operates with a bandwidth from 0 to 400 kHz and a signal-to-noise ratio of 144 dB, with balanced and asymmetric inputs. The amplifier is designed with high-quality components such as pure copper connectors gilded with fine gold and cryogenically frozen printed circuit boards. Dimensions are 430 x 85 x 290 mm, and it weighs 14.7 kg.