User Manual

HX-3 User Guide and Technical Information
6
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)