Mackie HM-400, 4-Channel Headphone Amplifier

Descriptions Mackie HM-400, 4-Channel Headphone Amplifier The Mackie HM-400 feature its rack-mountable, 4-channel headphone amplifier which is designed to provide a versatile headphone amplification for artists, musicians and engineers monitoring through headphones in live stage applications and home, project, commercial and mobile-recording studios. The Mackie HM-400 has also feature its stereo main output via XLR and 1/4" jacks and twelve 1/4" TRS stereo headphone outputs-three per channel-fed by a customizable blend of inputs. Additionally, the Mackie HM-400 has one stereo main input via XLR and 1/4" jacks can be mixed with a per-channel 1/4" stereo aux input. Each channel of the Mackie HM-400 offers a 2-band EQ for quick tone shaping, stereo balance or main/aux input mix control and output level adjustments. Also, on each channel are switches for muting left and/or right signals and operating in stero mono. Mackie HM-400 also has a 7-segment LED meters display main input and per-channel output levels. The Mackie HM-400 ships with an IEC power cable and occuppies 1 RU in a standard 19" rack. Mackie HM-400 Main Features Distribute signal to up to twelve pairs of headphones Occupies 1 RU One stereo main input via XLR or 1/4" jacks One 1/4" stereo aux input per channel One stereo main output via XLR or 1/4" jacks Three 1/4" headphone outputs—one on the front panel and two on the rear—per channel fed by an output level control 2-band EQ per channel for quick treble and bass adjustments Per-channel Balance knob allows control of left/right level balance or aux/main input mix Switches on each channel for L/R mute and St/2-Ch (stereo/mono) mode 7-segment LED metering for input and each output channel Heavy-gauge steel chassis for rugged durability Specifications Number of Channels  4 Input Connections  2 x XLR 3-pin balanced (one stereo pair) 2 x 1/4" TRS balanced (one stereo pair, also accepts 1/4"   TS unbalanced) 1 x 1/4" TRS stereo unbalanced for main input 4 x 1/4" TRS stereo unbalanced for aux inputs Output Connectors  2 x XLR 3-pin balanced (one stereo pair) 2 x 1/4" TRS balanced (one stereo pair, also accepts 1/4"   TS unbalanced) 12 x 1/4" TRS stereo unbalanced headphone outputs Maximum Input Level  Main Input: +15 dBu Aux Input: +20 dBu Maximum Output Level  Headphone Outputs: 550 mW per channel at 47 Ohms (   +21 dBu) Input Impedance  Main Input: 20 kOhms balanced, 10 kOhms unbalanced Aux Input: 10 kOhms unbalanced Output Impedance  Headphone Outputs: 3 Ohms unbalanced Gain Range  Main Input: -66 to +18 dBu Function Controls  Power on/off Main level knob L/R mute switches per channel Stereo/2-Ch switches per channel 2-band EQ per channel Balance knob per channel Output knob per channel Frequency Response  20 Hz to 20 kHz (±1 dB) THD  <0.01% (+4 dBu, 1 kHz, unity gain) Noise  -66 dB CMRR  Main Input: >42 dB at 1 kHz Display  1 x input level meter 4 x output level meters Power Requirement  100 to 120 VAC, 50/60 Hz, 24 W 220 to 240 VAC, 50/60 Hz, 24 W Power Connector  1 x 3-pin IEC male, 250 VAC, 10 A Construction Material  Heavy-gauge steel chassis Dimensions (H x W x D)  1.8 x 19.0 x 8.8" / 46 x 483 x 224 mm Weight  8 lb / 3.6 kg