Introduction - Lectrosonics DBa Instruction Manual

DBa

Introduction

DSW (Digital Secure Wireless) is designed for no-com-
promise applications where performance and security
are the highest priority.
A completely new digital architecture was developed
for the DSW wireless system, which includes the DBa
Transmitter. Extended operating range rivals the best
analog and Digital Hybrid Wireless
remarkable audio quality and only 2.5 ms of latency.
The system operates on standard UHF FCC Part 74
frequencies (TV channel band).
256-bit encryption is applied to the transmitted signal
stream for security against eavesdropping. The algo-
rithm conforms to the AES 256-CTR standard.
The DBa transmitter is a second generation design with
specially developed, high efficiency digital circuitry for
extended operating time on two AA batteries. The trans-
mitter can tune in coarse or fine steps across the UHF
television band from 470.100 to 691.175 MHz, with an
output power of 50 mW. The pure digital architecture
enables AES 256-CTR encryption for high level security
applications.
Studio quality audio performance is assured by high
quality components in the preamp, wide range input
gain adjustment and DSP-controlled limiting. Input
connections and settings are included for any lavaliere
microphone, dynamic microphones and line level inputs.
Input gain is adjustable over a 44 dB range in 1 dB
steps to allow an exact match to the input signal level,
to maximize the dynamic range and signal to noise
ratio.
A separate switch is provided on the top panel that can
be configured as a mute or power switch, or bypassed.
The housing is constructed of solid machined aluminum
for lasting ruggedness. The exterior is finished with an
ultra hard, black electroless nickel finish called ebENi.
Firmware updates are made through a side panel micro
USB port.
4
systems, with
®
Frequency Agility
The transmitter tunes across the entire frequency
range, from 470 MHz to 691 MHz.
Servo Bias Input and Wiring
The DBA input preamp is a unique design that delivers
audible improvements over conventional transmitter
inputs, is easier to use and much harder to overload.
It is not necessary to introduce pads on some mics
to prevent overload of the input stage, divide the bias
voltage down for some low voltage mics, or reduce the
limiter range at minimum gain settings.
Two different microphone wiring schemes are available
to simplify and standardize the configuration. Simpli-
fied 2-wire and 3-wire configurations provide several
arrangements designed for use only with servo bias
inputs to take full advantage of the preamp circuitry.
Other wiring schemes are compatible with Servo Bias
and conventional inputs.
A line level input wiring provides an extended frequency
response with an LF roll-off at 35 Hz for use with instru-
ments and line level signal sources.
DSP-controlled Input Limiter
The transmitter employs a digitally-controlled analog
audio limiter prior to the analog-to-digital converter.
The limiter has a range greater than 30 dB for excellent
overload protection. A dual release envelope makes the
limiter acoustically transparent while maintaining low
distortion. It can be thought of as two limiters in series,
connected as a fast attack and release limiter followed
by a slow attack and release limiter. The limiter recovers
quickly from brief transients, so that its action is hidden
from the listener, but recovers slowly from sustained
high levels to keep audio distortion low and preserve
short term dynamic changes in the audio.
LECTROSONICS, INC.