ATI DA103 User Manual

DA103 AND DMA103

AUDIO DISTRIBUTION AMPLIFIER

OPERATING AND MAINTENANCE MANUAL

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DESCRIPTION

Your DA103 and DMA103 Audio Distribution Amplifiers are inexpensive high performance amplifiers designed to split and isolate audio signal lines.

The DA103 accepts a line level input, balanced or unbalanced audio at –20, -10 or +4dBu nominal and provides a line level output at +4dBm nominal level to balanced or unbalanced output lines. The DA103 input/output connectors are two piece solderless “Phoenix” types, individual for each input and output line.

The DMA103 accepts a microphone level input signal and provides either line or microphone level outputs to drive balanced or unbalanced lines. Phantom microphone power is provided and all audio connections are made using XLR type connectors.

CIRCUIT DETAILS

The DA103 accepts a maximum line input level of +22dBu to high impedance (20Kohms) balanced instrumentation amplifier input (A1) and drives three servo balanced 600-ohm (minimum load) outputs (A3, A4, A5) up to +22dBm maximum. An internal input gain setting jumper plug optimizes the input stage gain, noise and headroom for nominal inputs at -20, -10 or +4dBu. The Master Gain control (R14a) adjusts all outputs simultaneously to compensate for input signal changes while individual output trimmers accommodate differing nominal output level requirements from -10dBu to +8dBm. Up to 40dB maximum gain is available. The servo-balanced outputs automatically detect single-ended (one side grounded) loads; remove the drive signal from the grounded output and double the signal applied to the ungrounded output thus maintaining equal gain for both types of loading.

The DMA103 boosts a microphone level input up to line level with up to 80dB gain. A low noise transformerless input stage (A1) allows internal DIPswitch (S1) selection of input gain from 10, 20, 40 or 60dB to optimally match low or high output microphones. A Master Gain control is provided and individual front trimmers match differing output level requirements from –10 to +8dBm. Phantom microphone power at regulated +20.2 VDC from A10 is selected with an internal DIPswitch and is sufficient for most powered microphones. +48VDC phantom power is also available as a plug-in option (PH48-1), consult factory. Three servo-balanced output drivers drive balanced or one side grounded loads and individual jumper plug 54dB output attenuators (P1, P2, P3) provide –50dBm microphone level outputs if necessary.

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DA 103 and DMA103 require 22 to 30VDC and are designed to share a common external 24VDC "Wall Wart" type power supply. A pair of loop-thru DC connectors on the rear of each module permits several units to be daisy-chained with P/N20602-1 DC power cables to a single power supply. The WA100-1 and WA100-2 (230VAC) are 400mA supplies. The DA103 and DMA103 both draw about 100mA at full output. Any combination, which adds up to less than the supply rating, can be powered by a single supply.

INSTALLATION

UNPACKING

Inspect the equipment. Shake it to see if anything is rattling around inside. If there is any visible damage to the unit or to the box it came in, contact the factory but do not return anything to ATI without prior authorization and shipping instructions. It may be necessary to have the shipping company inspect the unit and the box at your location. Count the pieces! Don't throw out the boxes and packing material until you are sure you have everything that is coming to you. NANOAMPS need either their own separately ordered WA100 power supply or a DC cable, P/N20602-1 to share the supply of another NANOAMP.

Rack and desk mounting hardware may be packed in with the unit even though ordered separately. Wall mount power supplies must be ordered separately but may either be included with the unit or shipped in their own box.

WIRING

AUDIO CONNECTIONS

DMA103 - balanced XLR type inputs and outputs are wired with pin 2 as HI and

pin 3 as LOW. Pin 1 is the cable shield and ground connection.

DA103 - line level audio connections are made to the Phoenix type two-piece connectors (Hi - Lo - Shld) using the rear label as a guide. Connectors separate with a straight pull toward the rear. Strip the wires cleanly without nicking, clamp them in the plug by tightening the screws and reinsert the plug into the receptacle.

Active balanced outputs and inputs require a reference ground connection to the source or receiving device for proper operation. This ground can be provided by the rack frame or a studio ground bus connection if the cable shield does not carry it through.

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