ATI Technologies ADA206XLR, ADA208XLR, ADA412XLR Operating And Maintenance Manual
DISTRIBUTION AMPLIFIERS
OPERATING AND MAINTENANCE MANUAL
www.atiaudio.com
DaySequerra
7209 Browing Road
© Copyright 2018, ATI is a registered trademark of DaySequerra Corp.
Pennsauken, NJ 08109 sales@daysequerra.com
www.atiaudio.com
PRODUCT DESCRIPTION
The ADA206XLR, ADA208XLR and ADA412XLR Analog Audio Distribution Amplifiers provide
two (206) or four (412) 1X3 distribution amplifier channels, and two (208) 1x4 distribution
amplifier channels, with balanced inputs and outputs. A master, gain adjustment for each
channel controls all three outputs together to adjust for varying inputs, while individual trimmers
for each output allow adjustment over a 20dB range to accommodate 10dbu semi-pro up to
+8dBm line levels.
Another of the ADA206XLR, ADA208XLR and ADA412XLR Distribution Amplifiers many
claims to fame is the use of XLR type input and output connectors. XLRs are easy to use but
make paralleling inputs for 1X6 or 1X12 operation difficult.
An LF347N quad bi-fet opamp forms the three variable gain output adjustment stages. These
variable gain stages use a unique circuit arrangement that allows us to provide a smooth,
logarithmic gain control for each output using an inexpensive (but good) linear cermet
potentiometer. Since we actually reduce the stage gain for low outputs rather than taking the
more conventional approach of reducing the input level to a fixed gain amplifier, you can use
the ADA at low output levels with very little noise penalty. You can use the ADA to match
consolemedium level inputs (-20dBu) or to drive semi-pro IHF inputs without requiring
outboard attenuator pads.
SSM2142 active balanced output drivers sense the voltage on their high and low output lines
and will shut off drive to a grounded output line while doubling the drive on the other. This
capability allows you to connect the outputs to balanced or unbalanced loads without regard
to whether or which side of the output is grounded. Maximum output at clipping is +22dBm into
balanced loads; however, even though the gain is the same under either condition, clipping
output is reduced by 6dB when driving an unbalanced load since the full output swing capability
of only one driver of the two is available.
The ADA family operates from a 15W – 24VDC single output switching supply featuring
universal AC input. Operating in the range of 85 – 264 VAC / 120 – 370 VDC, it offers low ripple
and noise at a max 150mV peak to peak.
www.atiaudio.com
DaySequerra
7209 Browing Road
Pennsauken, NJ 08109 sales@daysequerra.com
www.atiaudio.com
INSTALLATION
The ADA is designed for rack mounting on standard EIA 1-3/4 inch centers. Each unit
dissipates approximately 10 watts and is designed for use in an office environment. Avoid
excessive heat buildup (such as might be due to nearby power amplifiers in unventilated racks)
to ensure maximum component life.
AUDIO CONNECTIONS
XLR inputs and outputs are wired with pins 2 as HI and pins 3 as LOW. Pin 1 (shield) of all
input and output connectors are permanently grounded in accordance with current AES
recommendations. The pin 1 grounds are routed via a large, low impedance ground path
directly to the chassis separately from any audio ground paths. Internal circuit ground is also
connected to the chassis for shielding through an independent path. AC ground (green wire) is
also separately grounded to the chassis. Active balanced outputs require a reference ground
connection to the receiving device for proper operation. This ground is carried through pin 1.
If the pin 1 shield ground is not carried through to the receiving device, the AC ground, rack
frame, or studio ground system may complete this ground. Noisy grounds require excellent
common mode rejection in the receiving device for quiet system operation.
We have taken measures to keep RFI out of your ADA, including split and bypassed input
networks, beaded, bypassed and isolated power inputs, nonconcentric wound, semi-toroidal
power transformers, double ground plane PC boards and a nice enclosure to keep rain and
snow off the circuit boards. However, in difficult broadcast applications, the RF shielding and
suppression system can be no better than the ground system into which it is trying to dump the
unwanted RF. For optimal product performance, be sure to have a good grounding system.
ADJUSTMENTS
The Master and individual Output level controls should all be set close to 2 o’clock to provide
nominal +4dBm outputs for a nominal +4dBu input. These settings allow +6/-16dB output
adjustment range around nominal, which will allow outputs of +10 to -12dBm to be set. In
addition, the Master gain has +10dB to OFF adjustment range to compensate for input level
variations from -6dBu to input clipping at +24dBu.
www.atiaudio.com
DaySequerra
7209 Browing Road
Pennsauken, NJ 08109 sales@daysequerra.com
www.atiaudio.com
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