ATI Audio DA206 - Manual (Page 3)

ATI Audio Inc. ■ Tel: 856- 719-9900 ■ Fax: 856-504-0220 ■ [email protected] ■ www. audio.com
INSTALLATION
MOUNTING
Your DA 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 DA, 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.
Changing the position of the input gain compensates for lower level inputs by
setting jumper plugs P2, P3, P8 and P9. These plugs add 14 or 24dB of extra
gain to permit nominal inputs of -20dBu and minimum inputs as low as -30dBu
for +4dBm out.
The input paralleling jumper plugs (P4 & P5, P6 & P7, P10 & P11) are located
under the cover just behind the input XLR connectors. They must be used in