User Manual for Adastra RS Series Rackmount 100V Slave Amplifiers

Quick Guide from the Manual

The Adastra RS Series are rackmount 100V slave amplifiers designed for public address systems. They are intended to be fed from a mixer or mixer-amplifier signal output. Key safety requirements include ensuring correct mains voltage, using double-insulated speaker wire for 100V systems, and never connecting 8Ω and 100V terminals simultaneously. Ensure adequate ventilation and support when rack-mounting.

Front Panel Controls

The front panel features simple controls for operation:

• MASTER volume control: Adjusts the output level.
• LED indicators: Includes POWER, SIGNAL, and PEAK indicators.
• Power switch: Turns the unit on or off.

Rear Panel Connections

The rear panel contains all necessary inputs and outputs:

• Power: IEC mains inlet with fuse holder and voltage selector. RS120 and RS240 models also feature 24Vdc screw terminals for battery power.
• Speaker Outputs: Includes 8Ω terminal, 100V terminal, and COM (common) terminal.
• Signal: SLAVE IN (dual RCA) for receiving audio and SLAVE OUT (RCA) for daisy-chaining additional amplifiers.

Installation and Wiring

The amplifier can be configured for 100V line systems or low impedance systems. These configurations cannot be used together.

100V Line Systems

Connect the 100V output terminal to the positive (+) connection of the speaker and the COM output to the negative (-) connection. Connect further speakers in parallel. Ensure the combined wattage of all speakers does not exceed 90% of the amplifier's output power rating.

Low Impedance Systems

Connect the 8Ω output terminal to the positive (+) speaker connection and the COM output to the negative (-) connection. Ensure the speaker load is no less than 8Ω and the speaker's power handling is equal to or greater than the amplifier's output.

Operation

Turn the MASTER volume control fully down before switching on the power. Once powered, ensure the signal is active on the SLAVE IN inputs and gradually turn up the MASTER volume. The PEAK LED should only light momentarily; if it stays lit, reduce the volume to avoid distortion or clipping.

Troubleshooting

If you encounter issues, check the following:

• No power LED: Check the IEC lead, mains fuse, or battery charge (if using 24Vdc).
• Power LED on but no output: Check input signal connections and ensure the MASTER volume is turned up.
• Distorted output: Reduce the MASTER volume level; the input signal may be too high.
• Amplifier overheating: Ensure cooling vents are clear, verify that 8Ω and 100V speakers are not mixed, and check that the total load on the 8Ω output is not less than 8Ω.

Specifications

The RS Series includes four models: RS120, RS240, RS360, and RS480. All models feature 110/230Vac power supply. RS120 and RS240 support 24Vdc power. Output power ranges from 120Wrms to 480Wrms depending on the model. All units feature Master volume control and <1.0% THD.