Crown PIP-PA User manual

127411-1
3/99
Printed on
recycled paper.
© 1999 by Crown International, Inc., P.O. Box 1000, Elkhart, IN 46515-1000
U.S.A. Telephone: [phone]. Fax: [phone]. P.I.P. modules are
produced by the Professional Audio Division of Crown International, Inc.
Trademark Notice: Crown
®,
Macro-Tech
®,
Com-Tech
®,
IQ System
®,
IOC
®and
P.I.P.
®are registered trademarks of Crown International, Inc. Other trademarks
are the property of their respective owners.
P.I.P.–PA

P.I.P.–PA
Page 2

P.I.P.–PA
Page 3
1 Welcome
Thank you for purchasing the
Crown P.I.P.-PA accessory.
P.I.P.
®modules are designed to
quicklyinstallintherear panelof
many Crown amplifiers. P.I.P.
stands for “Programmable Input
Processor.” Their versatile fea-
tures expand the capabilities of
your amplifier and enable you to
customize it for your particular
needs.
The
P.I.P-PA adds a switchable
balanced low-Z microphone in-
put and a balanced line-level in-
put to each channel of a Com-
Tech
®or
Macro-Tech
®series
amplifier. A remote-control fea-
ture allows you to independently
switchbetweenthemicandline-
level inputs of each channel.
Designed for paging and back-
ground music systems, the
switching circuitry has built-in
delays for pleasing, less abrupt
fades from mic to line and visa
versa.
The mic inputs are transformer
isolated and employ a variable
gain stage. The gain of each
channelcanbeeasily controlled
from the rear panel. Phantom
power is also provided via the
microphone connectors. It can
be disabled by moving a jumper
on the circuit board.
Bassroll-off for eachmic input is
provided with a low-cut filter.
These filters roll off at 6 dB/oc-
taveandhavea–3dBfrequency
of150Hz.Theycan beindepen-
dently disabled by moving a
jumper on the circuit board.
Finally, each channel includes a
variable-threshold compressor
which is
IOC
®
error-driven at its
maximum setting or acts as an
audio feedback signal-driven
compressor at less than maxi-
mum settings.
Features
❏Remote switchable balanced
mic and line-level inputs with
custommute-delaycircuitryfor
pleasing fades.
❏Balanced1:1isolationtransform-
ers for mic inputs.
❏Adjustable mic input sensitivity.
Fig. 1.1 P.I.P.-PA

P.I.P.–PA
Page 4
❏Phantom power provided for
mic inputs (can be disabled).
❏Low-frequency filters for mic
inputs (can be disabled).
❏Variable-thresholderror-drivenor
audio feedback signal-driven
compressor.
❏Balanced RFI suppression is
provided at each input.
❏Gold plated edge-connector
for trouble-free connection to
amp.
❏Quick-connect barrier con-
nectors provide greater wir-
ing flexibility and make instal-
lation easier.
2 Facilities2 Facilities
2 Facilities2 Facilities
2 Facilities
A. Low-Cut Filter Jumper
A150-Hz,6-dB/octavelow-cutfil-
teris providedfor each mic input
only. (It has no effect upon the
line-levelinput.)Itcanbeusedto
attenuate unwanted pops and
noisewhichmicrophonessome-
times pick up. The filter of either
channel can be enabled or dis-
abled with the jumpers shown.
The on/off positions of the jump-
ers are labeled on the circuit
board.
B. Compressor Threshold
The threshold of each channel’s
compressorcanbeadjustedwith
these controls. When turned to
their maximum setting (full clock-
wise), the compressors respond
onlytotheIOCerror-signaloftheir
respective channel. When set
lower, the compressors are sig-
nal-driven by an audio feedback
signal.
C. Phantom Power Jumper
Phantom power (+18 VDC at 9
mA) is provided to the mic inputs
when these jumpers are set to
their “on” position. The on/off po-
sitions of the jumpers are labeled
on the circuit board.
D. Ground Isolation
Jumper
The input grounds can be iso-
lated from the chassis ground by
removing this jumper.
E. Balanced Line Input
Line-levelconnectionismadewith
these convenient quick-connect
barrierconnectors.Eachconduc-
toriseasilyattachedwith screws.
Once the cable is attached, the
connector can be quickly un-
pluggedand,ifdesired,movedto
a different line input.

P.I.P.–PA
Page 5
F. Balanced Mic Input
Low-impedancemiclineconnec-
tion is made with these connec-
tors in similar fashion as the line-
level inputs (E).
G. Mic Input Gain Control
Useasmall,flat-bladescrewdriver
to adjust the mic input sensitivity
with these controls.
H. Remote Switch Input
The remote control switches for
bothChannel1andChannel2are
attached to this connector. (The
ground leads are common.) With
no switch attached, the line-level
inputs (E) are normalled to the
amplifier inputs.
Fig. 2.1 Bottom View

P.I.P.–PA
Page 6
3 Installation
Before installing this P.I.P. mod-
ule, you’ll want to configure it.
1. Set the microphone phantom
power jumper of each chan-
neltothedesiredposition.The
on/off positions are labelled
on the circuit board (see Fig-
ure 2.1).
2. Set the microphone low-cut
filter jumpers of each channel
to the desired position. The
on/off positions are labelled
on the circuit board (see Fig-
ure 2.1).
3. Adjustthecompressorthresh-
oldofeachchannel. Afifteen-
mark scale is printed on the
circuit board (see Figure 2.1)
whichcorrespondstothetypi-
cal threshold settings shown
in the table in Figure 3.1.
Now you are ready to install the
P.I.P. in the amplifier.
Fig. 3.1 Compressor Threshold
Settings
Note: These voltage and power levels
are valid only for Stereo (Dual) and
Parallel-Monomodesofoperation.The
voltages shown must be doubled and
the power levels recalculated for
Bridged-Mono mode.
Alsonote:Themaximumoutputpower
isstrictlylimitedtothecapabilityofyour
amplifier. Any threshold setting above
themaximumoutputpowerofyouramp
willresultinthecompressoractingsolely
as a “clip” eliminator.
Installation Procedures
You may need a Phillips screw-
drivertoremovetheexisting P.I.P.
moduleorpanelfromyourampli-
fier.
CAUTION: Before connecting
thisorany
P.I.P. toyouramplifier,
it is important to turn its level
controls down, turn it off and re-
move the AC power. Don’t touch
the circuitry. Even though the

P.I.P.–PA
Page 7
amplifierisoff,therecouldstillbe
enough energy remaining to
cause electric shock.
1. Turn down the level controls
(fullcounterclockwise),turnoff
theamplifierandunplugitfrom
the AC power source.
2. Removetheexisting
P.I.P. mod-
ule or panel (two screws). For
PIP2 amplifiers, this may in-
volve disconnecting the P.I.P.
from a PIP2 input adapter (see
Figures 3.3 and 3.4). If a PIP2
input adapter is already
present,donotremovetherib-
bon cables from the adapter.
Otherwise you will have to re-
connect them in the next step.
3.
StandardP.I.P.Amplifiers :Align
theedgesofthe P.I.P.-PA inthe
P.I.P. cardrailsandfirmlypush
the unit in until it is seated
against the mounting bracket
(see Figure 3.2).
PIP2 Amplifiers: (Requires a
PIP2 inputadapter.Crownpart
number Q43528-1.) Connect
the PIP2 input adapter to the
two input cables of the ampli-
fier(seeFigure3.3).Noticethat
the PIP2 input adapter should
be positioned with the P.I.P.
edge connector on top and
facingawayfromtheamplifier.
The 20-pin cable (A) is con-
nected first then the 18-pin
cable (B) is connected. Both
A
B
B
A
18 PIN (B)
20 PIN (A)
Q43528-1
FROM AMPLIFIER
P.I.P.
MODULE
BACK PANEL
OF PIP2
AMPLIFIER
PIP2 CONNECTOR
BOARD
Fig.3.3 PIP2 Input Adapter
Connection
Fig. 3.4 Installation into a
PIP2 Amplifier
P.I.P.
MODULE
BACKPANEL
OFAMPLIFIER
Fig. 3.2 Installation into a
Standard P.I.P. Amplifier
ribbon cables should extend
below the PIP2 input adapter.
Next, insert the edge connec-
torofthe
P.I.P.-PA intothe PIP2
input adapter (see Figure 3.4)
and insert the assembly into
the P.I.P. openinginthebackof
the amplifier.
4. Secure the
P.I.P.-PA with the
two screws and lock washers

P.I.P.–PA
Page 8
provided. (The lock washers
are important because they
bind the P.I.P. to the chassis
ground of the amplifier.)
5. Connectinputandoutputwir-
ing.
6. Plug in the amplifier and turn it
on.Adjustitslevelcontrolstoa
desired setting.
Do not tamper with the circuitry.
Circuit changes made by unau-
thorized personnel, or unautho-
rized circuit modifications are not
allowed.
Remember: Crown is not liable
for any damage resulting from
overdriving other components in
your sound system.
Important:Iftheamplifierisused
in either Bridged-Mono or Paral-
lel-Monomode,you mustturnthe
Ch. 2 amplifier level control off
(fully counterclockwise). The in-
put and level control of Ch. 2 are
not defeated in mono mode so
any signal applied to Ch. 2 will
beat against the signal in Ch. 1.
Refer to the amplifier
Reference
Manual formoreinformationabout
Bridged-Mono or Parallel-Mono
modes of operation.
Mono-Mode Wiring
There are two ways to install the
P.I.P.-PA inamonoconfiguration.
One method uses the amplifier in
STEREO (Dual) mode. The other
methodusesBRIDGED-MONOor
PARALLEL-MONO mode.
If you want to use the
P.I.P.-PA in
a mono system but still want to
individually control the level of
each amp channel, follow these
instructions:Placetheamplifierin
STEREO(Dual)mode,beingcare-
fultofollowtheinstructionsinyour
amplifier's Reference Manual.
Then simply "daisy chain" the au-
dio signal from one input of the
P.I.P.-PA to the other. Either the
mic inputs or the line-level inputs
can be paralleled to give both
channels the same signal. (Daisy
chaining the inputs reduces the
input impedance to half.)
Youcanalsomixthistechniquein
any fashion you desire. For ex-
ample, you could daisy chain a
single microphone to both mic
inputs while feeding the line in-
puts each with a different line-
level feed and visa versa. In this
way you could feed background
music from a radio to one chan-
nel,audio froma tape recorder to
anotherchannel andenable both
channels to be interrupted by the
same paging mic.
The second method for wiring a
mono system gives less flexibility
at the inputs but provides more
power to a single mono output.
This technique requires that you
place your amplifier in either
BRIDGED-MONO or PARALLEL-

P.I.P.–PA
Page 9
MONO mode. Remember to fol-
low the instructions in your
amplifier's Reference Manual.
Thenconnectthemonoinputwir-
ingtothemicand/orline input of
Channel 1 only. Do not use the
input of Channel 2 while the
amplifier is in BRIDGED-
MONO or PARALLEL-MONO
mode and keep the amplifier’s
Channel 2 level control turned
down.
Input Cable Routing
Because the gain of a Crown
amplifier equipped with a
P.I.P.-
PA can be quite high (as high as
90dB)itisveryimportanttoexer-
cise care when routing the input
and output cables.
IMPORTANT: Use shielded wire
for mic input cables and avoidavoid
avoidavoid
avoid
routing them near the output
cables or noise and/or feedback
oscillationmay result. It is wise to
takesimilarprecautionswithline-
level inputs cables too.
To avoid hum, do not route the
input cables near power cables.
Switching Between Mic/Line
The line-level inputs are the de-
faultinputsifnoswitchisattached
to select the mic inputs. In this
case, each mic input is attenu-
ated54dBwhileeachlineinputis
delivered to the amplifier.
Whentheremoteswitch connec-
tion is shorted (that is, a switch is
installed and turned on) the line-
level input is attenuated 30 dB
and the mic input is delivered to
the amplifier.
A timed fader circuit causes the
switch from line to mic and mic to
linetobeasmooth transition.The
intentistocreateamorepleasing
transition for situations where the
line-level input is used to feed
background music and the mic
input is used for paging.
When the switch is activated, the
line-level input is muted after a
delay of 10 msec. Because it is
muted only 30 dB it is still barely
audible. The mic input turns on
almost immediately to insure that
no syllables of speech are lost,
giving an abrupt transition from
background music to paging.
When the switch is opened the
mic input is quickly muted 54 dB
in about 3 msec. The line-level
input is turned back on after a
lengthydelayof1.5seconds,pro-
vidingamorepleasingfadeback
to music after the page.
The remote line can also be con-
trolledwitha +5to +24VDClogic
line. For example, you could use
the Auxiliary control feature of an
IQ–P.I.P. or an MPX/SMX-6 multi-
plexer to control the mic/line
switching with an IQ System
®
. To
do this, add a 20 K ohm “pull
down” resistor across each re-
mote line. When the logic line is

P.I.P.–PA
Page 10
“Hi”theline-levelinputisenabled.
When it is “Lo” the mic input is
enabled.
Figure 3.5 shows how to connect
a remote switch (or logic line) to
each channel using the remote
connector.
Ground Isolation
If present, ground loop problems
canbereducedbyunsolderingor
cutting and removing the ground
jumper shown in Figure 2.1.
Whenremoved,thesignalground
isisolatedfromthechassisground
by a 2.7 ohm resistor as shown
below:
Fig. 3.5 Remote Switch Wiring
Fig. 3.6 Ground Isolation