ATI Audio DP100 User Manual

Page 4

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snow off the circuit boards. However, in a difficult broadcast application, high RF levels
may require a better ground path for the RF bypass networks than can be provided by the
third wire AC power line ground and a separate low inductance studio ground bus may be
necessary.

There are three wire grounded plugs. The power line ground could cause a loop with a
separate studio ground. If you are sure your studio ground will provide adequate
protection to personnel in case of an AC line short to chassis, a 3 to 2 AC adapter can be
used to isolate the power line ground. We recommend that the adapter be removed and
the power line ground reconnected prior to any service work requiring removal of the
studio ground from the chassis.

The four inch, silver bearing, low inductance copper strap which you are, of course, using
for your studio ground is not going to fit around the chassis ground screw on the
amplifier. Run the strap to within a few inches of the chassis and jump to the chassis
ground screw with shield braid. Any RF shielding and suppression system is going to be
no better than the ground system into which it is trying to dump the unwanted RF. If you
have a decent ground system and still have RF problems, give us a call.

INPUT AND OUTPUT CONNECTIONS

XLR audio inputs and outputs are all wired with Pin 2-Hi, Pin 3-Lo and Pin 1-Shield. All
Hi inputs and outputs are in phase.

The transformer coupled line outputs at J3 and J4 will drive either 600-ohm terminating
loads or high impedance bridging loads equally well. It is not necessary to resistively
terminate lines which feed bridging inputs, however, terminating a bridging line at the
load end with a 620 ohm resistor will sometimes help reduce RF pick-up between the
load point and the Interface.

A phono plug Y adapter (available at your nearest Radio Shack) can be used to turn your
MM100 bi-directional Interface into a Mono Summing Amplifier (Jumper L and R
outputs into LL) or a two output Splitter/Distribution Amplifier (L into LL and RR).
Simply jumping L into LL and R into RR makes a two channel Line/Buffer Amplifier
with up to 14dB gain.

MAINTENANCE

There is no routine maintenance required by your DP100 and MM100. If you have a
problem while using these Interfaces, eliminate by substitution source equipments,
cables, connectors and load as a possible cause before attacking the Interface. Once you
are positive that you have a problem inside the box, (A) call us for free in-warranty
factory service or (B) as a last resort, begin the disassembly process below.

This manual is related to the following products:

MM100