Sound Devices HX-3 Manual

HX-3
Headphone Distribution Amplifier
User Guide and Technical Information
Sound Devices, LLC
E7556 State Rd. 23/33 • Reedsburg, WI • USA
[phone] • fax: [phone]
Toll-Free: [phone]
www.sounddevices.com
suppor[email protected]

HX-3 User Guide and Technical Information
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Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
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 volume controls.
• Dynamic range exceeding 120dB.
• 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 or unbalanced ¼-inch and 1/8-inch stereo inputs.
• Loop output to connect additional HX-3’s in series for extra headphone outputs.
Flexible Powering
• Internal battery power (two AA) for convenient, low cost power.
• Excellent battery life - greater than 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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Specications
Frequency Response: 10 Hz – 50 kHz, +/-1.0 dB, any input to any output, gain control set to 50%
Voltage Gain: Gain Loop Out Headphone Output (1,2,3)
Bal. Line –3 dB 34 dB
HP Input –1 dB 35 dB
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
Dynamic Range:
(Balanced line inputs)
120 dB minimum
THD + Noise: 0.03% maximum (from 10 Hz – 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 –15V, regulated
Power: Internal: 2 AA alkaline batteries, 12 hours life typical driving one 75 ohm headset.
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 inter-
nal 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°C
32 to 160°F
Dimensions: 43 mm x 94 mm x 140 mm (h x w x d)
(1.7” x 3.7” x 5.55”)
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)

HX-3 User Guide and Technical Information
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Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
Front Panel Controls
12 3 4 5
1. Stereo/Mono Switch
Sums stereo and two-channel audio
program to mono for mono headphone
monitoring.
2. Headphone Gain
Controls Volume of each headphone
output.
3. Headphone Peak LED
Illuminates 3 dB before clipping to indi-
cate onset of headphone distortion.
4. POWER LED
Bi-color LED illuminates green when
the unit is powered and changes to red
when approximately four hours of bat-
tery life remain.
5. POWER Switch
Powers the unit from either Internal bat-
teries, or External DC. Seamless switcho-
ver from each power source.

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Input Panel Connectors
123
1. XLR Line Inputs
Line level, balanced inputs.
2. ¼-Inch and 1/8-inch Tape Level Inputs
Unbalanced, stereo, Tip-Ring-Sleeve
inputs.
3. Loop Output
Output connection enabling intercon-
nection of multiple HX-3’s. Loop Out is
T-R-S, unbalanced stereo connection.
Output Panel Connectors
123
1. HEADPHONE OUTPUTS
Panel mounted headphone jack for each
output. Output 1 has 1/8-inch jack in
parallel with ¼-inch jack.
2. BATTERY Compartment
Requires two AA batteries for operation.
Insert positive (+) end of battery first.
3. DC Input
Locking coaxial DC input accepts volt-
ages from 5 to 14 VDC.

HX-3 User Guide and Technical Information
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Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
Operational Notes
Headphone Outputs
The HX-3 uses independent drive circuits for each of its three isolated headphone circuits. Because of
the bi-polar power supply, the HX-3 can provide high levels of power to each headphone feed.
The HX-3 is capable of driving headphones to dangerous levels. Take precautions to prevent hearing damage.
Powering the HX-3
The HX-3 is designed to operate on two AA alkaline cells for approximately 15 hours into 75 ohm head-
phones (at nominal levels). The audio performance of the HX-3 does not vary throughout the life of the
batteries.
Several factors affect battery life including: battery chemistry, ambient temperature of operation, head-
phone impedances, headphone drive levels, and the number of headphones in use. The chart below can
be used as a starting point to estimate battery life. Experimentation is recommended to determine bat-
tery life for each individual setup. Note: Nickel-Cadmium batteries are not recommended in the HX-3
since these batteries have lower energy per cell than other types and will result in very short service.
Battery Type Operational Characteristics Battery Life
Duracell AA MN 1500 powered, idle 15 hrs.
Duracell AA MN 1500 driving single, 75 ohm headphones at nominal level 9 hrs.
Duracell AA MN 1500 driving three, 75 ohm headphones at high levels 8 hrs.
(Test conditions: 70º F)

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Connection Diagrams
The HX-3 can be used in a variety of headphone applications. Below are a few examples of interconnec-
tion setups using the HX-3.
Mixing
Console
Monitor L
Monitor R
One or more units can be added and “daisy-chained” for additional headphone feeds from a mixing
console. Loop additional HX-3 amplifiers with the included Link cable.
Mixing
Console
Monitor L
Monitor R
The headphone outputs of portable audio electronics can be connnected to the HX-3 for additional
headphone feeds. The included 1/4-inch to 1/8-inch can be used to connect the line-out or headphone
output to the HX-3.

HX-3 User Guide and Technical Information
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Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
CE Declaration of Conformity
According to ISO/IEC Guide 22
Sound Devices, LLC
300 Wengel Drive
Reedsburg, WI 53959 USA
declares that the product, HX-3 is in conformity with and passes:
EN55103-1, (1997) Emissions standard for product family audio devices for profes-
sional use
EN55103-2, (1997) Immunity standard for product family audio devices for profes-
sional use
EN55022 (1995)/
CISPR22 (1997)
Radiated and Conducted emissions, Class B
EN61000-4-2 (1997)/
IEC1000-4-2 1995
ESD - 6kV contact, 8kV air-discharge
EN61000-4-3 (2001)/
IEC1000-4-3 (2001)
Radiated RF immunity, 10 V/m, 80% 1 kHz amplitude modula-
tion
EN61000-4-4 (1995)/
IEC1000-4-4 (1995)
EFT Burst, I/O lines, ±0.25 kV to ±1.0 kV,
EN61000-4-6 (1996)/
IEC61000-4-6 (1996)
Conducted RF immunity, 10 V, 80% @1 kHz amplitude
modulation
Tested by L. S. Compliance, Inc. Cedarburg, Wisconsin
February 15, 2003
Matthew Anderson
Director of Engineering
Sound Devices, LLC
FCC Statement
This device has been tested and found to comply with the limits for a class B digital device, pursuant
to part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful
interference in a residential installation. This equipment generates, uses, and can radiate radio fre-
quency energy and, if not installed and used in accordance with the instructions, may cause harmful
interference to radio communications. However, there is no guarantee that interference will not occur in
a particular installation.

HX-3 User Guide and Technical Information
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Limitation of Liability
LIMITATION ON SOUND DEVICES’ LIABILITY. SOUND DEVICES, LLC SHALL NOT BE LIABLE TO THE PURCHASER OF THIS
PRODUCT OR THIRD PARTIES FOR DAMAGES, LOSSES, COSTS, OR EXPENSES INCURRED BY PURCHASER OR THIRD PAR-
TIES AS A RESULT OF: ACCIDENT, MISUSE, OR ABUSE OF THIS PRODUCT OR UNAUTHORIZED MODIFICATIONS, REPAIRS,
OR ALTERATIONS TO THIS PRODUCT, OR FAILURE TO STRICTLY COMPLY WITH SOUND DEVICES, LLC’S OPERATING AND
INSTALLATION INSTRUCTIONS. TO THE FULLEST EXTENT PERMITTED BY LAW, SOUND DEVICES SHALL HAVE NO LIABILITY
TO THE END USER OR ANY OTHER PERSON FOR COSTS, EXPENSES, DIRECT DAMAGES, INCIDENTAL DAMAGES, PUNITIVE
DAMAGES, SPECIAL DAMAGES, CONSEQUENTIAL DAMAGES OR OTHER DAMAGES OF ANY KIND OR NATURE WHATSOEVER
ARISING OUT OF OR RELATING TO THE PRODUCTS, THESE TERMS AND CONDITIONS OR THE PARTIES’ RELATIONSHIP,
INCLUDING, WITHOUT LIMITATION, DAMAGES RESULTING FROM OR RELATED TO THE DELETION OR OTHER LOSS OF AUDIO
OR VIDEO RECORDINGS OR DATA, REDUCED OR DIMINISHED AUDIO OR VIDEO QUALITY OR OTHER SIMILAR AUDIO OR
VIDEO DEFECTS ARISING FROM, RELATED TO OR OTHERWISE ATTRIBUTABLE TO THE PRODUCTS OR THE END USER’S USE
OR OPERATION THEREOF, REGARDLESS OF WHETHER SUCH DAMAGES ARE CLAIMED UNDER CONTRACT, TORT OR ANY
OTHER THEORY. “CONSEQUENTIAL DAMAGES” FOR WHICH SOUND DEVICES SHALL NOT BE LIABLE SHALL INCLUDE, WITH-
OUT LIMITATION, LOST PROFITS, PENALTIES, DELAY DAMAGES, LIQUIDATED DAMAGES AND OTHER DAMAGES AND LIABILI-
TIES WHICH END USER SHALL BE OBLIGATED TO PAY OR WHICH END USER OR ANY OTHER PARTY MAY INCUR RELATED TO
OR ARISING OUT OF ITS CONTRACTS WITH ITS CUSTOMERS OR OTHER THIRD PARTIES. NOTWITHSTANDING AND WITHOUT
LIMITING THE FOREGOING, IN NO EVENT SHALL SOUND DEVICES BE LIABLE FOR ANY AMOUNT OF DAMAGES IN EXCESS
OF AMOUNTS PAID BY THE END USER FOR THE PRODUCTS AS TO WHICH ANY LIABILITY HAS BEEN DETERMINED TO EXIST.
SOUND DEVICES AND END USER EXPRESSLY AGREE THAT THE PRICE FOR THE PRODUCTS WAS DETERMINED IN CONSID-
ERATION OF THE LIMITATION ON LIABILITY AND DAMAGES SET FORTH HEREIN AND SUCH LIMITATION HAS BEEN SPECIFI-
CALLY BARGAINED FOR AND CONSTITUTES AN AGREED ALLOCATION OF RISK WHICH SHALL SURVIVE THE DETERMINATION
OF ANY COURT OF COMPETENT JURISDICTION THAT ANY REMEDY HEREIN FAILS OF ITS ESSENTIAL PURPOSE.

HX-3 User Guide and Technical Information
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Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
Warranty and Technical Support
Warranty & Service
Sound Devices, LLC warrants the HX-3 against defects in materials and workmanship for a period of
TWO (2) years from date of original retail purchase.
This is a non-transferable warranty that extends only to the original purchaser. Sound Devices, LLC
will repair or replace the product at its discretion at no charge. Warranty claims due to severe service
conditions will be addressed on an individual basis.
THE WARRANTY AND REMEDIES SET FORTH ABOVE ARE EXCLUSIVE. SOUND DEVICES,
LLC DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WARRAN-
TIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
SOUND DEVICES, LLC IS NOT RESPONSIBLE FOR SPECIAL, INCIDENTAL, OR CONSEQUEN-
TIAL DAMAGES ARISING FROM ANY BREACH OF WARRANTY OR UNDER ANY OTHER LE-
GAL THEORY. Because some jurisdictions do not permit the exclusion or limitations set forth above,
they may not apply in all cases.
For all service, including warranty repair, please contact Sound Devices for an RMA (return mer-
chandise authorization) before sending your unit in for repair. Product returned without an RMA
number may experience delays in repair. When sending a unit for repair, please do not include ac-
cessories, including SSD drives, CF cards, batteries, power supplies, carry cases, cables, or adapters
unless instructed by Sound Devices.
Sound Devices, LLC
Service Repair RMA #XXXXX
E7556 State Road 23 and 33
Reedsburg, WI 53959 USA
telephone: [phone]
Technical Support / Bug Reports
For technical support and bug reporting on all Sound Devices products contact:
Sound Devices, LLC
E-mail: [email protected]
web: www.sounddevices.com/support/
Telephone: [phone] / Toll-Free in the U.S.A.: [phone]
Fax: [phone]
Sound Devices hosts a user support forum. The URL is:
http://forum.sounddevices.com
Sound Devices cannot guarantee that a given computer, software, or operating system configuration can be
used satisfactorily with the HX-3 based exclusively on the fact that it meets our minimum system require-
ments.

HX-3 User Guide and Technical Information- Printed in U.S.A.