RCF - UP 8504 • 4x125W / 100V or 70V power amplifier • Output power of 4x125W • Rated output line voltage 100V or 70V (selectable by switch on the rear panel independently for each channel) • Class D operation with transformerless galvanically isolated speaker output • Pair of switched power supplies (separately for mains power 115-230VAC and 48VDC) • Remote amplifier power on capability (contact closure, Stand-By/ON terminal, for all channels simultaneously) • Remote amplifier disable feature for energy saving or zoning (contact closure, Amplifier Disable terminal, for all channels simultaneously) • LED indicators: Master Vol. OFF, Amplifier Disabled, Thermal Protection, AC Mains Presence, AC Mains Powered, DC PSU Presence, DC PSU Powered • Dimensions: 482 x 44 x 375 (mm), 19"/1U • Weight: 5.5 kg Individual channel features (P8504 = four-channel, P8502 = two-channel, P8501 = single-channel): • Input 1: balanced, fixed sensitivity 0dBu (775mV, max 7V) • Input 2: balanced (mono) or unbalanced (stereo summed to mono), adjustable sensitivity -20 to 0dBu (78-775mV, max 7V, rear panel control) • Test Input: for test signal, unbalanced, fixed sensitivity 0dBu (775mV) • Priority 1 > 2: input 1 has priority, input 2 is attenuated, control by contact closure, all inputs are mixed at rest • Priority Test > 1+2: Test input has priority, inputs 1 and 2 are attenuated, control by contact closure, all inputs are mixed at rest • Optional band-pass filter 200Hz - 8kHz, 12dB/oct, switch on rear panel • Volume control on front panel (can be globally deactivated by switch on rear panel) • Remote volume control via external potentiometer (front panel control must be deactivated) • LED indicators: Signal (-20dB), Peak (0dB), Overload (protection activation, output muting)