Benchmark HPA4 - Key Features; THX AAA Amplifier Technology; Relay Control and I;O

Instruction Manual for HPA4 with 1.0.X Firmware – REV B Page 6
Features
 THX-888 Headphone Amplifier with THX AAA™ Technology
 Benchmark Line Amplifier
 256-Step Fully-Balanced Relay Gain Control, 0.5 dB Steps
 Precision Timed Relay Closures
 Precision Metal Film Resistors
 Gold-Contact Relays
 Balanced and Unbalanced I/O
 6 Watts into 16 Ohm Headphones
 11.5 Vrms into 300 Ohm Headphones
 0.1 Hz to 500 kHz frequency response
 SNR > 135 dB
 THD < 125 dB (0.00006%) under full load
 Short-Circuit Protection on Headphone Amplifier
 DC Protection on Headphone Amplifier
 Over-Voltage Protection on Headphone Amplifier
 Over-Current Protection on Headphone Amplifier
 Thermal Protection on Headphone Amplifier
 Full-Color 3.5" Capacitive Touch Screen
 IR Remote Control (optional)
 2 Balanced Stereo Line Inputs
 2 Unbalanced Stereo Line Inputs
 Balanced Stereo Line Output
 Unbalanced Stereo Line Output
 Balanced Mono Sum Output
 12V Trigger I/O – two bi-directional 12V trigger ports
 AUTO-ON Function - can be programmed to turn on when AC is applied
 Power Switch – very low standby power , <0.5 W at 120 VAC
 High-Efficiency Low-Noise Power Supplies – 100-240 VAC, 50-60 Hz
 Meets FCC Class B and CE emissions requirements
 Tested for immunity to radiated and conducted RF interference