Compact size and Light weight - all models only 1 RU and 12 kg (26 pounds) for easier racking and shipping Powersoft legendary universal switch mode power supply up to 300VAC tolerant , compact, high performance Power Factor Correction (PFC), reducing AC mains current draw and increasing voltage operating range (universal power supply) Detachable AC mains cord Low Inrush Limiting reduces AC inrush current, removing the need for expensive power sequencers Fixed frequency switch mode output stage for highest grade audio accuracy Patented output filter with ripple cancellation network Front panel LCD interactive display and LED level meters Lockable user menu for setting max output voltage, max mains current draw, digital gain/attenuation control, defeatable gate selection per channel, limiter and real time Gain/sensitivity user selection capability (Digital gain attenuator) Built-in defeatable Clip limiters for each channel Monitoring of: load impedance, AC mains voltage and current, output voltage, internal temperature Downloadable log file of all functional fault events with time related trace Hardware monitor available for fast local diagnostics Built-in Remote Control (RS 485 interface) for full diagnostic, operational setting and system monitoring, Armonía compatible Temperature controlled continuous variable speed fan, front to rear airflow Smart card reader for preset load/save, firmware upgrades and step-up power to K8/K10 (or K3) Power on/off muting: for 4s at power on, and upon power off amplifiers outputs are muted Neutrik® XLR/1/4" Combo balanced input (link out on K2/K3) and Speakon® output connectors Fully protected circuitry design including DC, infrasonic, high frequency, thermal overload and short circuit Comprehensive protection circuitry: DC protection: protects against infrasonic signals VHF protection: protects the loudspeakers against strong very high frequency non-musical signals above the audible range. Thermal protection: prevents the amplifier from being overheated. The protection indicators on the front panel are switched on, as a warning, before the protection process is initiated. AC protection: shuts down the power supply if the line voltage is outside the operating voltage. Clip limiter: prevents severely clipped waveforms from reaching the loudspeakers, whilst maintaining full peak power.