RDL RU-ASX4D Datasheet

RACK-UP® SERIES

Model RU-ASX4D

Stereo Audio Selector 4x1

 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
 Open-Collector Output for Selected Input


Controllable Using Various RDL Remote Controls

The RU-ASX4D is part of the group of RACK-UP products from Radio Design Labs. RACK-UPs feature the advanced circuitry for which RDL
products are known, combined with accessible user-friendly controls and displays. The ultra compact design permits high-density installations,
with three products mounted in a single rack unit! Optional brackets permit mounting a RACK-UP module above, below, or in front of any flat
surface!

APPLICATION: 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 sets of stereo dual-led VU meters, one on the front panel, the other on the rear panel. The
maximum input level is +25 dBu.

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 concurrently activate local and remote control, 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 and can be re-programmed at any time.

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.

RDL  659 6th St.  Prescott, AZ., USA 86301  [phone]  FAX [phone]  www.rdlnet.com

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RACK-UP® SERIES

Model RU-ASX4D

Stereo Audio Selector 4x1

STEP 1: Determine the type of remote control to be used for source selection. Momentary controls use four open-collector transistors or switches (these may be relay contacts,
pushbuttons or RDL remote controls) to momentarily connect one input control terminal to ground; one input terminal corresponds to each of the four audio inputs.
Sequencing controls use a single input terminal (SEL terminal); a momentary HI (+15 to +24 Vdc) pulse applied to this terminal advances the module to the next audio
source; an RDL D Series-RCS4 is typically used. Set the MODE 1 switch to the appropriate remote control type.
STEP 2: Determine if the module should power up to the “last source used” (before power to the unit was turned off), or if the module should always power up to a pre-defined
source. Set the MODE 2 switch for the desired power-up source operation.
STEP 3: Determine if the VCA activity display should continuously display the last direction change, or if it should only display activity during adjustment. Set the MODE 3 switch for
the desired display.
STEP 4: Determine if any remote devices are to be switched by the module when a source is selected. Connect the remote devices to the SLAVE (open-collector) output terminals
on the module. The RU-ASX4DR and the remote devices must share a common ground connection.
STEP 5: Connect the remote controls to the appropriate control terminals.
STEP 6: Connect audio to each input that is to be used. With the audio sources active, select each source and adjust the audio level on the rear-panel trimmer, as indicated on the
dual-LED VU meters on the rear of the unit.

Installation/Operation

Declaration of Conformity available from rdlnet.com.

Sole EMC specifications provided on product package.

Specifications are subject to change without notice.

The PGM pushbutton is used to store which input will be active on power-up if MODE switch 2 is set to the OFF position. Press and hold
the PGM button during power up to enter the programming mode. Release the PGM button when the front-panel input select LEDs flash
twice (to indicate that the unit is in programming mode). The LEDs will display the stored input source. NOTE: If all four LEDs are off,
then no source is selected (unit powers-up with all sources off). Press the PGM button to advance to the next source as indicated by the
front panel LEDs. When the desired input is selected no further action is required. After three seconds the unit stores the indicated
source and flashes all four source selection LEDs twice to indicate

ramming is complete.

RDL  659 6th St.  Prescott, AZ., USA 86301  [phone]  FAX [phone]  www.rdlnet.com