Sound Devices HX-3 User's Guide

©2001 Sound Devices, LLC

HX-3 Headphone

Distribution Amplifier

User Guide and Technical Information

™

SOUND DEVICES

Sound Devices, LLC

300 Wengel Drive

Reedsburg, WI 53959 USA

Voice 608.524.0625

Fax [phone]

www

.sounddevices.com

HX-3 Headphone Distribution Amplifier

User Guide and Technical Documentation

2

General Description

The HX-3 from Sound Devices is a portable, stereo headphone amplifier
designed for critical audio monitoring. The audiophile-quality headphone
amp is ideal for adding headphone feeds for portable and studio appli­cations.

The HX-3 provides three independent headphone feeds from balanced
or unbalanced, line sources. Each headphone output has its own level
control, peak LED, and ¼-inch output connector. With its extended
bandwidth and high drive capability the HX-3 can drive headphones of
various impedances to high levels with very low distortion, important for
monitoring in high SPL environments. It is powered from two-AA batter­ies or external DC.

The HX-3 will provide years of superb audio performance under the
most punishing field conditions.

Features

High Performance Headphone Amplifier

 Three independent headphone outputs with individual gain controls.
 Dynamic range exceeding 120 dB.
 10 Hz to 50 kHz audio bandwidth.
 Capable of driving headphones to high levels with very low distortion.
 Peak indicators show overload of each headphone feed

.

 Stereo / mono switch.

Flexible Inputs / Outputs

 Two balanced XLR line level inputs
 Unbalanced ¼-inch and 1/8-inch stereo inputs.
 Loop output to connect additional HX-3s in series for extra headphone outputs.

Flexible Powering

 Internal battery power (two-AA) for convenient, low cost power.
 Excellent battery life >10 hours (nominal drive level with alkaline batteries).
 External 5-17 VDC powering.

Durable Mechanical Construction

 High strength aluminum chassis withstands punishing field conditions.
 Strap loops on each side for easy mounting or wearing.
 Panel-mounted connectors for strength and reliability.
 Easy access battery compartment for quick battery changes.

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©2001 Sound Devices, LLC

www.sounddevices.com

Specifications

Frequency Response: 10 Hz - 50 kHz, +/- 1.0 dB, any input to any output, gain

controls set to 50%

Voltage Gain:

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

+16 dB 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

Note: only one set of inputs (balanced or unbalanced) should
be connected at a time.

Loop Output: Unbalanced, 200 ohm output impedance

Internal Voltage Rails: +15 V and -15 V, regulated

Power:

Internal

: 2 AA alkaline batteries, XX hours life typical with nomi-

nal

External:

5 - 17 VDC via threaded coaxial connector (5.5 mm
outer diameter, 2.1 mm inner diameter), pin positive, sleeve
negative. Voltages above 17 VDC cause no damage to unit, but
will open an internal poly fuse. Poly fuse will reset when voltage
is removed.

Power LED: Green indicates power and good battery. Red indicates power

with low batteries. LED turns red when approximately 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 Tip-Ring-Sleeve interconnect cable

Rubber feet (4)
Locking DC plug

Gain Loop Out Headphone Output (1,2,3)

Bal. Line -3 dB

34 dB

HP Input -1 dB 35 dB