Portable, Battery-Powered Headphone Distribution Amplifier

The compact HX-3 Headphone Distribution Amplifier is the perfect accessory to quickly provide three high-performance stereo headphone feeds with individual level controls from line-level sources. The HX-3 can produce very high headphone levels with extremely low noise and distortion.

Great for radio, television, film, and music production applications, the battery-powered HX-3 accepts balanced XLR line-level inputs or unbalanced 1/4-inch and 1/8-inch stereo inputs. Its 1/4-inch loop-out can connect multiple HX-3's for additional headphone outputs. Headphones are connected to panel-mounted 1/4-inch stereo connectors.

The HX-3 has a durable aluminum chassis to withstand the punishment of field and studio environments. The unit is powered by inexpensive batteries (two-AA) or external 5-18 VDC.

The HX-3 can add headphone outputs to the 442, 302, MixPre, MM-1, and USBPre.

Features

Three isolated headphone outputs with individual volume controls.
125 dB dynamic range with flat frequency response.
Durable 1/4-inch connectors, panel mounted for strength.
Stereo or mono monitoring.
Peak LED indicates headphone overload.
Two balanced XLR line level inputs or unbalanced 1/4-inch and 1/8-inch stereo inputs.
Loop Output to connect additional HX-3's in series.
All-metal connectors solidly mounted to the chassis for durability and RF immunity.
Free from "Pin-1" grounding problems.
Internal battery-power for up to 18 hours from two AA alkaline batteries.
Chassis-isolated 5 to 18 VDC input for easy external DC powering.
Power LED indicates low battery power.
High strength, extruded aluminum chassis with protective metal end panels.

HX-3—with HD600 headphones

Specifications

Frequency Response:
10 Hz - 50 kHz, -±1.0 dB, any input to any output, gain controls set to 50%

Voltage Gain:
34 dB from balanced line to headphone output, 35 dB from headphone input to headphone output

Output Clipping Level:
+18 dBu minimum with 600 ohm load, +16 dBu minimum with 300 ohm load

Headphone Output Impedance:
200 ohms

Input Clipping Level:
XLR: +24 dBu minimum
1/4-inch and 1/8-inch inputs: +22 dBu minimum

Dynamic Range:
(balanced line inputs): 120 dB minimum

THD + Noise:
0.03% maximum (from 10 Hz to 22 kHz @ +10 dBu input and output level, 300 ohm load, 10 Hz - 22 kHz filter bandwidth)

Inputs:
XLR: electronically balanced, 22k ohm input impedance, 1/4-inch unbalanced: 9.1k ohm impedance
1/8-inch unbalanced: 9.1k ohm impedance.

Internal Voltage Rails:
±15 V, regulated

Power Source:
Internal: 2 AA alkaline batteries, 18 hours life typical with nominal levels. External: 5 - 17 VDC via threaded coaxial connector (5.5 mm outer diameter, 2.1 mm inner diameter), pin positive, sleeve negative.

Power LED:
Green indicates power and good battery. Red indicates power with low batteries. LED turns red when ~ 4 hours of battery life remain.

Operating Temperature Range:
0 to 70 degrees C
32 to 160 degrees F

Dimensions:
43 mm x 94 mm x 140 mm (h x w x d) (1.7" x 3.7" x 5.5")

Weight:
(unit only): 0.56 kg
1.24 lbs.

Included Accessories:
1/4-inch to 1/8-inch trs interconnect cable, rubber feet (4), locking DC jack