RDL 4x1 Stereo Balanced Audio Switcher - Terminal Block



* Ex GST. Check with us for the latest pricing

Diagram | Related ProductsFour Frequency Audio Test Tone Selection Datasheet

The RU-ASX4D is a four channel stereo audio selector with input gain adjustments and output level metering. The inputs and outputs are connected on rear-panel detachable terminal blocks.

Each of the four stereo line level inputs accepts either a balanced or an unbalanced signal. Each input is equipped with a rear panel screwdriver-adjustable input gain trimmer. Input signal levels between -15 dBV and +8 dBu may be set to the proper operating level as indicated by a stereo dual-LED VU meter. This assures ample headroom at all normal operating levels. The module is equipped with two identical dual-led VU meters, one on the front panel, the other on the rear panel. The maximum input level is +25 dBu.


  • Local or Remote Controlled Switching
  • Multiple Switching Control Points
  • 4 Stereo Inputs to 1 Stereo Output
  • Line-Level Audio Switching
  • Balanced or Unbalanced Inputs and Output
  • Gain Trim on Each Source
  • Controllable Using Various RDL Remote Controls
  • Open-Collector Output for Selected Input

The RU-ASX4D was designed for absolute silent switching of audio signals using only solid-state switching circuitry.

The output is stereo line level. Each output channel may be connected balanced or unbalanced. Each of the VU-meters, left and right, is calibrated to read +4 dBu for the corresponding balanced output.

A front-panel LOCAL/REMOTE switch enables either the front-panel buttons or the rear-panel remote control terminals provided on detachable terminal blocks. In the LOCAL mode, four keyboard style long-life pushbuttons on the front panel are used to select one input. When a button is pushed, the corresponding audio input is fed to the output and any previously selected source is shut off. Only one source may be selected at a time. If the button for a selected source is pushed again, all inputs are turned off. An LED above each pushbutton indicates the selected source. In the REMOTE mode, inputs are selected by a sequential remote control such as an RDL D-RCS4, by a momentary remote control such as an RDL D-RC4M or by an external open-collector momentary closure to ground. The RU-ASX4D may be remote controlled from a single or from multiple locations. When a source is selected, the RU-ASX4D provides a 25 mA open-collector output to control other equipment or modules.

Rear-panel DIP switches are provided to permanently activate the remote control terminals, to select the remote control mode (sequential or individual source selection), and upon power-up a return to either a pre-programmed source or to the last source used. The pre-programmed source is stored when the module is installed.

The RU-ASX4D offers exceptional headroom, very low distortion, excellent crosstalk isolation, wide flat frequency response and extremely low noise with very high common-mode signal rejection. It provides exceptional audio performance for the most critical applications in a professional audio environment.

The RU-ASX4D operates from 24 Vdc connected through a rear-panel detachable terminal block.


Audio Inputs (4):
Stereo, Line level on Detachable Terminal Block

Input Impedance:
> 20 kΩ balanced, >10 kΩ unbalanced

Input Level (for +4 dBu output):
-15 dBV to +8 dBu, adjustable on rear-panel trimmers

Maximum Input Level:
+25 dBu

Common Mode Rejection:
> 60 dB (50 Hz to 120 Hz)

Headroom (above +4 dBu):
> 20 dB (unity gain)

Frequency Response:
10 Hz to 20 kHz (±0.2 dB)

Distortion (THD + N):
< 0.01% (20 Hz to 20 kHz)

Noise (below +4 dBu):
< -85 dB (with any input selected); < -95 dB (with no input selected)

Off Attenuation:
> 85 dB (1 kHz), > 70 dB (20 kHz)

< -85 dB (1 kHz); < -65 dB (20 kHz)

Front-Panel Switches:
Momentary pushbuttons (4, 1 per input), LOCAL/REMOTE latching pushbutton

Front-Panel Indicators (11):
Power, Selected channel (4), LOCAL/REMOTE selector (2), L and R Dual-LED VU meters (4)

Audio Output:
Stereo, Line level on Detachable Terminal Block

Output Impedance:
150 Ω balanced, 75 Ω unbalanced

Output Level:
+4 dBu balanced, unbalanced output 6 dB below balanced output level

Control inputs (5):
1 mA, pulled to ground (4, source selection); 1 mA, pulled to +15 Vdc (SEL)

Control outputs (5):
25 mA, open-collector to ground

Rear-Panel Indicators (4):
L and R Dual-LED VU meters

RDL Remote Control Compatibility:

Power Connection:
Detachable Terminal Block

Power Requirement:
24 Vdc @ 150 mA, Ground-referenced

Ambient Operating Environment:
0° C to 55° C

WEEE Weight:
1.26 lbs

Shipping Weight:
1.515 lbs

Tariff Code:

Diagram | Related Products | Four Frequency Audio Test Tone Selection | Datasheet



Australia: sales@avw.com.au
Syd: 02 8213 0200  Mel: 03 8691 5210 Qld: 07 3607 3785 WA/SA/NT: 08 8120 3203

New Zealand: sales@avw.co.nz
Akl: 09 271 4000 Wel:  04 499 3888

Login Create an Account
Make one in 30 seconds without any annoying questions!