GAIN STAGE
A low noise NE5532 section (A1A) provides 26dB maximum gain. A linear control is used in a unique circuit configuration to provide a wide range logarithmic MASTER gain control characteristic in a variable gain stage with optimum noise performance. Output noise at unity gain is low enough to allow performance to exceed
LINE OUTPUT
The balanced output stage of the SUM100 utilizes a unique active balanced output driver IC, the Analog Devices SSM2142, that senses whether the connected load is balanced and floating or is unbalanced due to either side being grounded. A balanced output load will be driven with equal and antiphase levels on the HI and LO output lines.
An unbalanced (one side grounded) load will cause the driver IC to shut off the signal output to the grounded side of the load and double the output level applied to the other side, thus maintaining equal output to either type of load. The output stage provides 6dB gain and will drive loads of 600 ohms and higher. Nominal output is +4dBm with clipping at +22dBm (10Vrms) into 600 ohm balanced loads for 18dB nominal headroom. Maximum output is reduced to +20dBu (7.8Vrms) when driving an unbalanced load since the full output swing of only one driver is available. This still provides a very comfortable 30dB of headroom above the typical
POWER SUPPLY
The SUM100 requires 22 to 30VDC and are designed to share a common external 24VDC "Wall Wart" type power supply. A pair of
INSTALLATION
UNPACKING
Inspect the equipment. 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
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