User manual CREST AUDIO HD4 SPECIFICATIONS

[. . . ] Wide-bandwidth output devices assure detailed, transparent high frequency response. And, thanks to Crest's exclusive IGM circuit, the HD4 will drive 2 loads safely without compromise in performance. HD4 Features · Crest's legendary "overbuilt" power supply · Toroidal power transformer · Latest generation of high-speed, wide-bandwidth output devices · Twin Tunnel Cooling with back-to-front air flow · Dual, variable speed DC fans · Massive, extruded aluminum heat sinks · Balanced XLR and 1/4-inch (TRS) inputs · 5-Way binding post outputs · Stereo/Parallel/Bridged Mono mode selector switch · Ground lift switch · TourClass® protection circuits: - ACL (Active Clip Limiting) prevents speaker damage with gentle gain reduction at clip threshold. - IGM (Instantaneous Gain Modulation) monitors connected loads to detect conditions that may overstress output devices, allowing safe operation into nominal 2 impedances. [. . . ] At 4 ohms, 20Hz - 20kHz, 0. 1% THD+N, it shall deliver a minimum of 400 watts per channel. In bridged mono mode with an 8 ohm load, 20Hz - 20kHz, 0. 1% THD+N, it shall deliver a minimum of 800 watts. Two rear panel mounted variable speed DC fans (filters detachable without tools) shall provide back to front air flow through the chassis. The amplifier shall have circuitry to protect itself from output short circuits, thermal overload or other adverse load conditions. The amplifier shall protect speaker loads from DC voltage on outputs. The amplifier shall have active clip limiting and impedance sensing circuitry. Output relays shall protect the speakers from amplifier failure. Each channel shall have a standard (factory-set) input sensitivity of 0. 775 Volts, and shall be fitted with an internal jumper which allows the gain to be altered to X20 or X40. The hum and noise level shall be 105 dB below rated output, "A" weighted. SMPTE IMD shall be less than 0. 01% at rated power, 60Hz and 7kHz. The amplifier shall have a class AB output stage. The frequency response shall be 20Hz-20kHz, +0, -0. 3dB at rated power. The amplifier will operate at 100V-240V, 50-60 Hz AC (configured at factory). Maximum current draw shall not exceed 15 amperes at 120VAC (limited by front panel breaker for bench tests). Front panel indicators shall include Active, Protect, Signal, and Clip LED's for each channel. Front panel attenuators shall be recessed and detented. [. . . ] Paramus, New Jersey 07652 USA ·· B AB B 1 3- Power figures are watts per channel, both channels driven. Crest Audio reserves the right to make improvements in manufacturing or design which may affect specification. Crest Audio specification literature is available in electronic form to qualified users. [. . . ]