Power Output: 250W RMS Frequency Response: 70Hz to 15kHz ±1dB Distortion: Less than 1% Hum & Noise: (20Hz to 20kHz) MUSIC: -70dB; TEL: -70dB; MIC: -55dB Sensitivity: MUSIC: 85mV; TEL: -20dBm (77mV); MIC: 600¼V Tone Control: BASS: ±9dB @ 100Hz; TREBLE: ±9dB @ 10kHz Regulation: 2dB Inputs: TEL: 600-ohm balanced line, transformer-isolated MUSIC: Hi-Z source, RCA jacks or screw terminals MIC: LO-Z balanced, screw terminal connection MUSIC MUTE: Mutes music during a microphone page CONTACT RING: Sounds night ringer tone when customer-supplied dry contacts are closed TEL RING: Sounds night ringer in response to 90V ring signal BRIDGING: Permits bridging of two amplifiers Outputs: 25V and 70V. Provision for WMT1A line-matching transformer. Controls & Indicators: POWER & PEAK LEVEL LED indicators. APHEX,TREBLE, BASS,VOX SENS, RINGER VOLUME, MUSIC MUTE, MUSIC VOLUME, MIC VOLUME, TEL VOLUME, ALC controls (screwdriver-adjustable) Overload Protection: Thermal and electronic overload protection. 6.0A slow blo fuse Power Requirements: 120V AC, 60Hz, 5A Operating Temperature: -4°F (-20°C) to 131°F (+55°C) Finish: Black with silver lettering Dimensions: 19" W x 10-1/2" H x 3-13/16" D Shipping Weight: 31 lbs.