Protech Audio 899B - Manual (Page 2)

INSTALLATION
The 800 Series Audio Distribution Amplifiers are
designed to be mounted in the Model 857B Card
Frame, or the Model 858B Card Frame.
The Model 857B Card Frame will accomodate up to
10 audio cards and requires an external power supply.
(Model 66708). The Model 858B will accomodate up to
9 audio cards and has an internal power supply. (Model
2000-PS-A)
Both card frame assemblies bus the DC power to the in-
dividual card slots, and provide screw-type barrier termin-
ation points for audio and DC connections.
The determination as to which backplane assembly to use
in your project, was made prior to our factory receiving
the order. The backplane assembly you have received
will accommodate the group of cards you or your designer
have specified.
4- Unpack each individual card, inspect for shipping
damage, and assuming none is found, slide the
card
half-way into the appropriate slot. After all cards have
been installed half-way into the card frame, plug in one
card at a time and turn on the power supply. Make sure no
unusual loading is noticed at the power supply. If loading
is noticed, turn off the power supply, unplug the card and
recheck terminations. If no loading is noticed, continue
inserting each card in the card frame, checking power
supply loading as each card is plugged in. When all the
cards have been plugged in, the installation is complete,
and all that remains is the alignment.
Each 800 Series card with line level inputs has been
shipped from the factory aligned for unity gain. This
alignment optimizes headroom. If additional gain is
required, the following alignment procedure is recom-
mended;
This completes the installation and alignment of your 800
Series Audio Distribution amplifiers. The cards may be
expected to deliver years of uninterrupted service.
Page 2
ALIGNMENT
The actual steps necessary for installation of the 800
Audio Distribution Amplifier cards, are comparable to
those necessary for any of the 800 series cards. They are
as follows:
1- Mount the card frame in an appropriate EIA 19" width
rack, using 4 screws of sufficient tensile strength to
provide secure mounting.
2- A determination has been made as to which type of
power supply will be used on your system. Follow the
instructions for the type of power supply you will be
installing.
EXTERNAL POWER SUPPLY. If an external power
supply is to be used, terminate the proper supply
connections to pins 1, 2, & 3 of the DC barrier connector,
as shown in the card frame layout drawing. Turn on the
power supply, and using a DC voltmeter, check for
correct voltage and polarity at pins 1, 2, & 3 of the barrier
connector.
INTERNAL POWER SUPPLY. If a plug-in power supply
card is to be used, plug in the supply card, and check for
proper illumination of both the positive and negative
voltage LED's, on the power supply card.
3- Terminate all audio input and output connections, using
the card connection drawing on the facing page. Double
conductor shielded cable is recommended for all audio
connections. Terminate each unused input with a 1K ohm
resistor.
Apply a signal representative of the
actual signal level to be used, to the
input.
While monitoring the #1 output chan-
nel, turn the output #1 gain trimpot
clockwise (increased gain), or coun-
terclockwise (decreased gain) until
the output signal reaches the de-
sired level.
Repeat step #2 for each output on
your distribution amplifier. For any
unused output, leave the gain
trimpot in the maximum counter-
clockwise position.
Note 1-
The alignment procedure outlined above will almost al-
ways provide the desired output level. However, when
an unusually low input signal level is present (less than -
20dB), the installer may wish to use the additional gain
available in the input gain stage. This gain should be used
only when each output has already been adjusted to the
maximum gain setting.Using this gain in systems which do
not require in excess of 20dB of gain, will result in reduced
headroom.
Note 2-
The alignment procedures for INTEGRA III Series cards,
differ from card type to card type. Therefore it is necessary
to consult the alignment procedure for each type of card
being installed, to properly align a card frame using
different card types.
1 -
2 -
3 -
INTEGRA III SYSTEM
CONNECTOR DRAWING
MODEL 899B
PROTECH AUDIO
NOTES.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
GROUND
OUT 2B HI
OUT 2B LO
OUT 2A LO
OUT 2A HI
INPUT 2 HI
INPUT 2 LO
GROUND
OUT 1B LO
OUT 1B HI
OUT 1A LO
OUT 1A HI
GROUND
INPUT 1 LO
INPUT 1 HI
857B & 858B BACKPLANE CONNECTIONS
INPUT 1
OUTPUT 1B
OUTPUT 1A
INPUT 2
OUTPUT 2A
OUTPUT 2B