Ashly manual Operating Manual - SRA-120Power Amplifier, 7.2Input Sensitivity Switch

Operating Manual - SRA-120 Power Amplifier

In situations where the power amp and its signal source are separated by great distances, a ground voltage difference may exist between the amp’s chassis ground and the input cable’s ground. Connection of these two grounds through the jumper strap may cause large ground currents to flow (which is known as a ground loop), caus- ing a hum noise in the amp’s output. Unless you have such a situation with a hum problem that cannot be solved by using balanced input connections, the ground jumper strap should remain in place.

7.2Input Sensitivity Switch

This switch selects between a 0 dBu input sensi- tivity in the "out" position for use with professional au- dio sources, and -10 dBu input sensitivity in the "in" po- sition for use with low line-level sources such as tape decks, CD players, DAT machines, etc.

7.3Normal/Bridging Switch

This switch selects between NORMAL mode in the “out” position where both outputs are in-phase with their respective inputs, and BRIDGED mode in the “in” position where channel 1 output is switched out of phase with it's input. In BRIDGED mode, the channel 2 red bind- ing post becomes the (+) in-phase speaker output terminal

and the channel 1 red binding post becomes the (-) out-of- phase speaker terminal. To properly operate in bridged mono mode, the Mono switch must also be selected.

7.4Stereo/Mono Switch

This switch selects between stereo mode in the "out" position and mono mode in the "in" position. In mono mode, channel 1 input is sent to both amplifier chan- nels, and is controlled through the channel 1 level con- trol.

7.5Speaker Outputs - Binding Posts

A pair of dual banana binding posts provide the stereo speaker outputs. The minimum load impedance is 4 ohms per channel in normal mode, and 8 ohms in bridged mode. In BRIDGING mode, the channel 2 red binding post is the (+) in-phase speaker output terminal and the channel 1 red binding post becomes the (-) out-of-phase speaker terminal.

CAUTION! NEVER CONNECT THE TWO RED BINDING POSTS TOGETHER OR CONNECT EITHER RED BINDING POST TO A BLACK BINDING POST!

8.TYPICAL APPLICATIONS

8.1Stereo Sound Reinforcement System

In this situation, the audio source feeding the SRA-120 is a professional level (0dBu) stereo mixer. All three mode switches should be in the "out" position.

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