OXMOOR DCA-2T Digital Control Attenuator
The Oxmoor line of attenuators and remote controls constitute a unique, high quality system for the remote control of audio levels. Over the years, many audio professionals around the world have come to rely upon our remote volume control products, especially in situations where other remote volume controls have failed to meet quality and long-term wear and tear standards.
At the heart of our remote volume control products is our DCA-2T digital control attenuator. The DCA-2T is a sleek, rack-mountable box that provides control of two discrete audio channels (90 dB of isolation provided for two unrelated programs), or control of a single stereo program.
Multiple DCA-2Ts can be linked together to provide up to 64 discrete channels. The DCA-2T features user-assigned preset levels to control the amount of attenuation at power up, eliminating unpredictable or unknown turn-on state, as well as a "priority" function to set a temporary system level upon a switch closure, ideal for fire alarm or paging applications.
Precise volume control can be provided at as many locations as required. Our RC-16 remote controls are easily wired and linked together using simple RJ-11 modular telephone cables. Up to four RC-16 remotes can be connected to a given control input. There are 29 steps of precise 1.5 dB attenuation from 0 to -43 dB, with a 30th step for 90 dB "full kill" attenuation.
The RC-16 is actually a highly sophisticated shaft encoder which translates knob movement into a string of digital pulses. Unlike standard "Up and Down" volume controls, the RC-16 is sensitive to rate of change between steps – so 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 direction. Since there are no mechanical stops, a knob cannot be "twisted off" if it is turned beyond what would be the stop positions on a conventional level control.
The DCA-2T features electronically balanced inputs and balanced transformer-isolated outputs, with XLR connectors. It is used with the Oxmoor RC-16 remote volume control and requires one rack space.
DCA-2T Part Number: 2500002
Product specifications
| Frequency Response |
20 Hz to 20 kHz
-3 dB Points, Ref. 1 kHz |
+0, -0.3 dB
4 Hz to 60 kHz (+4 dBm Output) |
| Hum and Noise |
Unweighted |
-80 dB (ref. 0 dBm output @ unity gain) |
| Distortion |
Ref. +4 dBm Output @ Unity Gain |
| THD + Noise |
0.002% (20 Hz to 20 kHz BW) |
| SMPTE IMD |
0.002% (60 Hz + 7 kHz, Mixed 4:1) |
| Transient Intermodulation |
0.004% (3.15 kHz SQ + 15 kHz Probe, 30 kHz BW) |
| Crosstalk |
Channel to Channel (20 Hz to 20 kHz, Input Terminated w/600 Ohms, Adjacent Channel Driven to 0 dBm) |
-90 dB |
| Audio Input |
Type |
Electronically Balanced (RF Suppressed) |
| Connector |
Female XLR |
| Pin Out |
Pin 1 Shield (Chassis), Pin 2 +, Pin 3 – |
| Input Impedance |
80 k Ohms |
| Nominal Input Level |
+0 dBu |
| Maximum Input Level |
+20 dBu |
| Trim Pot Gain Range |
±15 dB (Ref. 0 dBu Output) |
| Audio Output |
Type |
Balanced, Transformer-isolated |
| Connector |
Male XLR |
| Pin Out |
Pin 1 (Chassis), Pin 2 +, Pin 3 Shield |
| Source Impedance |
75 Ohms |
| Recommended Load Impedance |
600 Ohms or Greater |
| Nominal Output Level |
0 dBu |
| Maximum Output Level |
Ref. 1 kHz @ Rated THD |
| Terminated w/600 Ohms |
+18 dBm (All Outputs Driven Simultaneously) |
| Unterminated |
+20 dBu |
| Digital Attenuator |
Control Range |
0 to -43.5 dB in 29 Steps Plus a 90 dB Full Attenuation "Kill" Step |
| Tracking Accuracy (Ch. to Ch.) |
Within ±0.1 dB Throughout Attenuator Range |
| Preset and Priority Range |
15 Steps (of 3 dB each) Plus "Kill" |
| Control Loop |
Maximum Controls Per Channel |
4 |
| Maximum Channels Per Control Loop |
64 |
| Maximum Cable Length |
600m (2000 ft)1 |
| Contact Requirements |
Single Pole Switch or Open Collector Transistor (128 mA capacity), Dry Closure to Logic Ground |
| Wiring Scheme |
Daisy-Chained Connection Via Looping Jacks |
| Cable and Connectors |
6-Wire Modular Telephone type RJ-11/12 |
| Safety Listing |
City Of Los Angeles |
| Mains Power |
Power Requirements |
100 to 125 VAC or 200 to 230 VAC 50/60 Hz; 8 Watts Maximum |
| Mechanical |
Overall Dimensions |
44H x 482W x 183D mm
(1.72 H x 19 W x 7.18 D in)
|
| Finish |
Textured Black Paint |
| Shipping Weight |
3.8 kg (8.5 lb) |
| Net Weight |
3.1 kg (6.9 lb) |
1 Total length based on typical modular telephone cable resistance of 12 ohms per 100m (330 ft).
Specifications subject to change without notice. The term DCA is a trademark of the Oxmoor Corporation.
Architect and engineer's specifications
Digital control Attenuator (DCA). Two-channel audio attenuator utilizing precision D/A converters. Range of attenuation: 43.5 dB in 29 steps, plus a -90 dB full attenuation ("kill") position. Front panel (recessed) ±15 dB trim controls. Each channel may be controlled independently or ganged for stereo. Channel tracking: ±0.25 dB over entire attenuation range when ganged for stereo operation. Attenuation position self-contained and not effected by disconnection of remote controls. Frequency response: +0, -0.3 dB, 20 Hz - 20 kHz. Hum and noise (ref. +0 dBm output at unity gain): -80 dBu, unweighted. Distortion (ref. +4 dBm, 20 Hz to 20 kKz): THD or IMD, 0.1% or less, 20 Hz - 20 kHz. Audio inputs: electronically balanced, 3-pin XLR-type. Input impedance: 80 K ohms. Audio outputs: balanced transformer-isolated, 3-pin XLR-type. Source impedance: 75 ohms. Maximum input/output level: +20 dBu. Remote control ports: "volume up," "volume down," "preset," and "priority." User-adjustable wake-up level ("preset") on power up. User-adjustable momentary level change ("priority") through external contact closure. Mounting: rack-mountable, one EIA rack space (44.45 mm; 1.75 in.).
Acceptable: Oxmoor DCA-2T
