Oxmoor DCA-2 - Manual

Oxmoor Corporation, LLC, 309 Cahaba Valley Parkway, Birmingham, AL 35124 USA Toll Free: 1-800-262-6898
Phone: 205-982-8200 Fax: 205-982-8250 E-mail: [email protected] Internet: www.oxmoor.com
Precise volume control can be provided at as many
locations as required. The remote units are easily wired,
in “daisy-chain” configuration, using simple modular
telephone style cables. Up to four RC-16 remotes can
be connected to a given control input (and that remote,
or string of remotes, can be “daisy- chained” to control
up to 64 audio channels). The system provides 29 steps
of precise 1.5 dB attenuation from 0 to -43.5 dB, with a
30th step for 90 dB “full kill” attenuation. Virtual
display of the set attenuation is simultaneously given
at all locations via a circular LED array around the
knob on each RC-16 Remote Control. The RC-16 can be
mounted in a standard two-gang electrical wall box, or
a pre-punched 2-gang plate is available from Oxmoor.
The RC-16 is actually a highly sophisticated shaft
encoder which translates knob movements into a string
of digital pulses; the pulses then alter the level of the
digital attenuator(s) within the DCA-2 chassis. Unlike
up/down buttons, the RCA-16 is sensitive to rate-of-
change, and thus the faster the knob is turned, the
faster the setting is changed. As any interconnected
RC-16 knob is turned, the LEDs on all remotes in the
chain follow until the upper or lower limit is reached.
At that point, the knob will continue to turn, but the
level and Virtual Pointers simply stop changing until
any one of the knobs is turned in the opposite direc-
tion. Since there are no mechanical stops, a knob can-
not be “twisted off” if it is turned beyond what would
be the “stop” positions on a conventional level control.
For applications where access to one or more remote
controls must be restricted, a key switch can be
installed in place of a jumper on the back of the RC-16;
the key switch must then close to activate the RC-16.
DCA-2/DCA-2T DIGITAL CONTROL ATTENUATOR
& RC-16 REMOTE CONTROL
The Oxmoor DCA-2 Digital Control Attenuator™ and
one or more RC-16 Remote Control™ units together
constitute a unique, high-quality system for the re-
mote control of audio level. The DCA-2 is a compact
(1-3/4” high) rack mountable package that can control
two discrete audio channels (90 dB of isolation is
provided for two unrelated programs) or the two
channels can be linked to control a single stereo pro-
gram. Multiple DCA-2s can be linked, and up to 64
discrete channels can be controlled in a single chain
with 1/4 dB tracking tolerance between channels.
Designed for professional applications, the DCA-2 is
equipped with XLR-type input and output connec-
tions. Additionally, Channel A & B maximum gains
can be adjusted
±
15 dB from the nominal unity gain of
the system via recessed, front-panel controls. Maxi-
mum cable length from the DCA-2 to the farthest
remote is approximately 2,000 feet.
The Oxmoor system includes a number of unique
features. A Preset control on the DCA-2 rear panel sets
the degree of attenuation on power up, avoiding an
unpredictable or unknown turn-on state. One or both
channels can be switch-reset back to this “Preset” level
at any time. Another rear panel control, labeled “Prior-
ity,” sets a level to which the system can be temporarily
forced by an external switch closure. Each RC-16 re-
mote has terminals for preset and priority functions.
The switch itself is not included.
The DCA-2T outputs are transformer balanced. Either
system is capable of driving 600 ohm or higher imped-
ance loads; maximum output is +18 dBm terminated,
+20 dBu unterminated.
With the Oxmoor RC-16's Virtual Pointer, you
can see where the volume is, wherever you are.
PRESET PRIORITY
CH. A
CH. B
CH. A
CH. B
CH. A
CH. B
3
2 1
3
2 1
G G
G
IN
OUT
IN
OUT
ON-BOARD LOGIC
2 1
3
G
2 1
3
AUDIO
SHAFT
ENCODER
CUP
CDN
IN
OUT
LOGIC
RC-16 REMOTE CONTROL
Attenuator
Attenuator Trim Pot
Trim Pot
Block diagram of the DCA-2 and RC-16