ATI Technologies L200 Operating And Maintenance Manual
L200
LINE/SUM/MIKE AMPLIFIER
OPERATING AND MAINTENANCE MANUAL
© Copyright 1997-2005, Audio Technologies Incorporated - Printed in USA
Audio Technologies Inc. | 154 Cooper Road #902 | West Berlin, NJ 08091 | Voice 856-719-9900 | Fax 856-719-9903 | www.
audio.com
DESCRIPTION
Your L200 Dual Line/Buffer Amplifier is an inexpensive, high performance
amplifier, which is ideal as a gain block, attenuator, impedance converter,
summing amplifier and signal splitter.
The inputs provide balanced 40Kohm bridging impedance for line levels up to
+24dBm. The high input impedance allows the L200 input to also bridge -10dBu
(hi-fi, RCA plug) lines without loading.
Front panel, screwdriver adjust, full range gain controls provide 26dB gain at full
clockwise rotation, unity gain at twelve o’clock and a smooth audio taper to full
off.
The output drivers are servo controlled, ground-sensing circuits, which will supply
over +22dBm to 600 ohm balanced loads and +20dBu to high impedance,
unbalanced loads. The L200 uses rugged XLR type input and output connectors.
Loop-through DC connectors allow several NANOAMPS to share a single
external 24VDC power supply. Battery packs and DC-DC converters for portable
use are also available.
Up to three NANOAMPS will mount side-by-side in only one rack unit using the
available rack mounting kits. Your L200 may also be neatly stacked or mounted
side by- side on your desk with the available angled desk mounting kits.
CIRCUIT DESCRIPTION
INPUT STAGES
The balanced input stages of the L200 Line Amplifier utilize a FET input LF347
quad opamp in a clean, quiet inverting instrumentation amplifier configuration.
Input levels up to +24dBm will be handled without clipping, excess levels cause
only clean clipping without hang-up or phase reversal. Equal -6dB gains from
both HI and LO inputs allow unbalanced sources to be easily accommodated.
Bridging impedance is a high 40Kohms with good CMR.
GAIN STAGES
A low noise NE5532 provides 26dB maximum gain. Inexpensive linear controls
are used in a unique circuit configuration to provide a logarithmic 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 16-bit digital
dynamic range even at -10dBu nominal output.
Audio Technologies Inc. | 154 Cooper Road #902 | West Berlin, NJ 08091 | Voice 856-719-9900 | Fax 856-719-9903 | www.
audio.com
LINE OUTPUT
Balanced output stages of the L200 utilize 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 -10dBu nominal unbalanced signal.
POWER SUPPLY
The L200 requires 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 permit 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 L200 draws 70mA. Any combination of
which add up to less than the supply rating can be powered by a single supply.
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
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. They need either their own separately ordered WA100
power supply or a DC cable, P/N20602-1 to share the supply of another.
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.
Audio Technologies Inc. | 154 Cooper Road #902 | West Berlin, NJ 08091 | Voice 856-719-9900 | Fax 856-719-9903 | www.
audio.com
Loading...