ATI Technologies ADA208PH, ADA416PH Operating And Maintenance Manual
DISTRIBUTION AMPLIFIERS
OPERATING AND MAINTENANCE MANUAL
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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 ADA208PH or ADA416PH provides two (208) or four (416) independent one-in by four-out
circuit groups. A four-output feed is sufficient for many applications; however, if you need more
outputs, you can parallel channels by bridging several inputs across the same line for 1X8, 2X8
or 1X16 operation. Since each input circuit has 30k ohms balanced input impedance, you can
simply terminate your source line with a single 620 ohm resistor (if necessary) and then parallel
as many inputs as necessary across it.
Each input can bridge line levels up to +24dBm without clipping. Common mode hum signals
are attenuated by 70dB and the input resistor network is split and heavily bypassed for good
protection from RF signals riding on the input lines. The input differential amplifier operates at
slightly less than unity gain to optimize input headroom and to prevent any signal clipping from
occurring prior to the gain controls.
Each output consists of an adjustable gain stage driving the HI output terminal along with a
unity gain inverter stage. The inverter drives the LO output in opposite phase to provide an
active balanced output. The adjustable gain stage utilizes a unique circuit arrangement that
allows us to provide a smooth, full range logarithmic gain control for each output using a linear
cermet potentiometer. This circuit provides 20dB gain at full clockwiserotation, unity gain in the
12 o'clock position and tapers smoothly to full off at the fullCCW position. Since we actually
vary the gain of the output stage rather than taking the more conventional approach of
adjusting the input level to a fixed gain stage, you can use the ADA at low output levels with
very little noise penalty. You can easily match the ADA outputs to console medium level inputs
(-20dBm) or drive semi-pro RCA inputs (single ended at .10Vrms) without requiring outboard
attenuator pads.
Each balanced output stage is isolated from the output terminals by DC blocking capacitors
and 400 ohms of build-out resistance. The build-out resistors are split and bypassed to prevent
any RF signals that might be picked up on an output line from feeding back into the ADA.
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DaySequerra
7209 Browing Road
Pennsauken, NJ 08109 sales@daysequerra.com
www.atiaudio.com
The ADA has clipping indicators to warn you of overdriven and overloaded outputs. These
indicators individually sense nonlinear operation of any output channel by measuring the error
voltage at the feedback terminal of the HI side output amplifier. If any single output or any
combinations of outputs are driven too high, they will light the clipping LED. Each clipping
indicator monitors only four outputs, making it easy to locate the "hot" output.
The ADA 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 Series Distribution Amplifier is designed for rack mounting on standard E.I.A. 1-3/4
inch centers. Each unit dissipates approximately 10 watts and is ventilated through slots in the
rear panel.
WIRING
There are three wire grounded plugs. The power line ground could cause a loop with your
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 be reconnected
prior to any service work requiring removal of the studio ground from the chassis.
To allow maximum flexibility in grounding in high RF environments, the ADA circuit grounds are
isolated from case ground. For normal operation, add a ground jumper from any Phoenix
connector ground terminal to the chassis ground screw.
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 #6 chassis ground screw on the amplifier rear panel.
Run the strap to within a few inches of the chassis and jump to the chassis ground screw with
shield braid.
We have taken serious measures to keep RF out of your ADA. This includes split and
bypassed input and output resistor networks, beaded, bypassed and isolated power inputs,
non-concentric wound power transformers and double ground plane PC boards. However, in a
difficult broadcast application, 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. For optimal product
performance, be sure to have a good facility grounding system.
Audio inputs and outputs should be connected using the rear panel labels as a guide. HI
outputs are all in phase with each other and in phase with the HI inputs.
www.atiaudio.com
DaySequerra
7209 Browing Road
Pennsauken, NJ 08109 sales@daysequerra.com
www.atiaudio.com
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