250-Watt Stereo PA Amplifier Owner’s Manual Please read before using this equipment.
ˆ Contents Contents .................................................................................................................................. 2 Features .................................................................................................................................. 3 Preparation ............................................................................................................................. Presetting the Controls .......................................................
ˆ Features Your Public Address Amplifier gives you the versatility and power you need in a professional sound system. Its wide frequency response easily handles amplification of voice and music. Use it in meeting halls and auditoriums, at sports events, in schools, and in the office for paging systems — anywhere you need to deliver special announcements with excellent sound. The amplifier (if bridged) produces up to 350 watts of clean, powerful sound with minimum distortion.
ˆ Preparation PRESETTING THE CONTROLS MOUNTING THE AMPLIFIER Before you begin making connections or using your amplifier, preset the audio input source’s and the amplifier’s controls to avoid overdriving a channel or producing sudden unexpected loud sounds. Warning: To prevent possible hearing loss, set the audio input device’s and amplifier’s controls as indicated in the following sections. After you turn on the amplifier or change the program source, adjust the controls to a comfortable listening level.
The following drawings show recommended speaker placements for typical, narrow, and wide sound coverage. Typical Coverage Narrow Coverage (single speaker) Wide Area Coverage (two speakers) ˆ Connections CONNECTING AN INPUT SOURCE is off and the AC power cord is not plugged in. You can connect a component such as an audio mixer or preamplifier to the inputs on the back of your amplifier. Each input (labeled INPUT and INPUT MONO) has a balanced and unbalanced jack.
amplifier. Then, make sure STEREO/MONO on the back of the amplifier is set to MONO. speakers, use this table to determine the wire length and choose the appropriate gauge. Wire Length GROUNDING THE INPUT SOURCE To avoid a low frequency hum, connect your audio mixer’s or preamplifier’s ground wire (usually black or green) to the GND terminal on the back of the amplifier.
RIGHT terminals for each channel (as SPEAKERS RIGHT terminals (as shown shown here). here). To connect the speaker wires to the amplifier, turn the knob on the terminal counterclockwise until it stops, insert the bare wire inside the space between the knob and the amplifier, then turn the knob clockwise until it stops to secure it. 3. Make sure STEREO/MONO is set to STEREO. Bridged Connection Use this connection only if you have highpower speakers that can handle a power output of 350 watts.
ˆ Using Your Amplifier 1. Start the input sound source. 3. Press POWER to turn on the amplifier. nal exceeds the output power level you set using LEFT and RIGHT, warning you of possible damage to the amplifier. If this happens, reduce the output level of the connected sound source or LEFT and RIGHT until the indicator flickers only at peak volume levels. 4. One at a time, adjust LEFT and RIGHT to the desired volume level. USING SPEAKER A/B 2.
Listening Safely • Do not listen at extremely high volume levels. Extended high-volume listening can lead to permanent hearing loss. To protect your hearing, follow these guidelines when you use headphones. • Once you set the volume, do not increase it. Over time, your ears adapt to the volume level, so a volume level that does not cause discomfort might still damage your hearing. • Set the volume to the lowest setting before you begin listening.
ˆ The FCC Wants You to Know Your amplifier might cause TV or radio interference even when it is operating properly. To determine whether your amplifier is causing the interference, turn off your amplifier. If the interference goes away, your amplifier is causing it.
ˆ Specifications Input Impedance .......................................................................................................... 20 kOhms Continuous Output Power Stereo at 1 kHz .............................................................................. 125 Watts × 2 (8 ohms) Stereo at 1 kHz .............................................................................. 175 Watts × 2 (4 ohms) Bridged at 20 Hz to 20 kHz ..................................................................
Limited One-Year Warranty This product is warranted by RadioShack against manufacturing defects in material and workmanship under normal use for one (1) year from the date of purchase from RadioShack company-owned stores and authorized RadioShack franchisees and dealers.
