85 x 4 4-Channel Trunk Mount Amplifier
(120-1977)                     Features                Faxback Doc. # 16920

The Radio Shack 85 X 4 High Power 4-Channel Trunk Mount Amplifier is 
designed to produce a total of 340 watts to give added punch and power
to your vehicle's existing stereo system.

The amplifier produces up to 85 watts per channel of clean, powerful sound
at all audio frequencies with minimum distortion.  You can adjust the
crossover frequency for both channels 3 and 4 when using only two speakers 
and a subwoofer, so you can emphasize the bass sounds but not lose the 
other sounds or power.  You can connect your autosound system's line-level
or speaker level outputs to the amplifier.

Its features include:

14k Gold-Plate Noise-Isolated - let you connect low-level (pre-amplifier)
Line-Level Input Jacks          signal inputs to match your autosound
                                system's output for the best high-fidelity
                                performance.

     14k Gold-Plated Speaker -  designed for low impedance, high
     Terminals                  conductivity, and minimum corrosion to
                                provide the highest signal transfer and
                                lowest sound distortion.

         Input Level Controls - let you adjust the level of the audio
                                signals that enter the amplifier.

    Automatic Power Switching - automatically turns on/off the amplifier
                                when you turn on/off your autosound system.

          Bridging Capability - lets you combine the amplifier's four 85-
                                watt channels so you can use the system
                                with only two channels that produce a total
                                of 170 watts from each channel.

  Crossover Frequency Circuit - lets you adjust the crossover frequency 
                                from 45-400 Hz for both channels three and
                                four when you use only two speakers.

   Crossover Frequency ON/OFF - lets you set the amplifier to drive a
                                connected subwoofer.

 Automatic Thermal Protection - automatically lowers the amplifier's output
 System (ATPS)                  power when the amplifier's internal
                                temperature reaches 202 degrees F then
                                increases the output power when the
                                amplifier cools down.

         Mute Turn On Circuit - eliminates the irritating thump noise that
                                some amplifiers produce when you turn them
                                on.

              Power indicator - lights when power is on.

     Full MOSFET Power Supply - produces enough power to supply the main 
                                amplifier and has a considerable amount of
                                reserve power for peak "high demand"
                                situations.

     Short Circuit Protection - distorts sound if any output channel shorts
                                so you can know to turn off the amplifier.

Important:  Be sure your speakers can handle 340 watts of power (170 watts
            per channel if you connect the autosound system to one pair of
            speakers. or 85 watts per channel if you connect the autosound
            system to two pairs of speakers).  Each speaker must have an
            impedance of at least 4 ohms.  Your local Radio Shack store
            carries a full line of speakers.

NOTE:  If the connectors on your vehicle stereo system are not compatible 
       with the amplifier's connectors, your local Radio Shack store sells
       adapter harnesses for many vehicles.