Preparing the Speaker Wire

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You can achieve a proper total impedance by combining series and parallel connec- tions.

Use the shortest length of wire possible to connect the speakers. After placing the speakers, use this table to determine the wire length and choose the appropriate gauge size:

Wire Length	Wire Gauge


25 feet or less	18 gauge

Over 25 feet	16 gauge

Connecting Only One Speaker

Connect the speaker’s negative (–) terminal to COM (common) on the back of the amplifi- er. Then connect the speaker’s positive (+) terminal to the speaker terminal (4Ω, 8Ω, or 16Ω) on the back of the amplifier that match- es the speaker’s impedance.

8Ω Speaker

Note: If you connect speakers without trans- formers, the speaker wire should be no long- er than 50 feet (see “Connecting Speakers with Transformers” on Page 11).

To prepare the speaker wire, remove about 1 inch of insulation from the end of the speaker wire you are connecting to the amplifier. Then twist the exposed wire to secure all of the wire strands.

To connect speaker wire to the amplifier, press the push terminal lever on the amplifier for the connector you want, insert the end of the wire into the terminal’s hole, then release the lever to secure the wire.

Connecting Two Speakers In Series

Follow these steps to connect speakers in series.

Left Speaker

Right Speaker

1. Connect the left speaker’s positive (+) terminal to the right speaker’s negative

(–) terminal.

	2. Connect the left speaker’s negative (–)
Terminal Levers	terminal to COM on the back of the
	amplifier.

3. Connect the right speaker’s positive (+) terminals to the speaker terminal (4Ω, 8Ω, or 16Ω) on the back of the amplifier that matches the total speaker imped- ance.

Connections			9

MPA-125 specifications

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One of the standout features of the MPA-125 is its impressive power output. With a rating of 125 watts per channel at 8 ohms, this amplifier ensures that audio signals are delivered with clarity and precision, making it suitable for driving a wide range of speakers. The 2-channel design allows for stereo applications, providing a rich and immersive listening experience. Additionally, the MPA-125 can operate at a low impedance, ensuring compatibility with various speaker configurations.

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User-friendly design is another hallmark of the MPA-125. The front panel includes easy-to-use volume controls, indicator lights, and speaker output terminals. The amplifier is designed for straightforward integration into existing audio setups, making it accessible for users of all experience levels. The balanced XLR inputs provide a secure and noise-free connection, ideal for professional audio applications.

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Overall, the Radio Shack MPA-125 is a reliable and powerful amplifier that brings out the best in audio equipment. Its combination of solid performance, user-friendly features, and advanced technologies makes it an excellent choice for anyone looking to elevate their audio experience, whether for casual listening or professional use.