OPERATION MANUAL
P2850 • P2950
Dual Channel Power Amplifiers
C12 • C22 • L20
Plug-In Controller Modules
P2850/P2950 OPERATION MANUAL
Cautions
CAUTION
TO AVOID ELECTRIC SHOCK, DO NOT
INSERT FINGERS OR OBJECTS INTO
ANY OPENINGS IN THE CABINET
WARNING: TO PREVENT FIRE OR ELECTRIC
SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO
RAIN OR MOISTURE
Explanation of Graphical Symbols
The lightning flash with arrowhead symbol,
within an equilateral triangle, is intended to alert
the use to the presence of uninsulated "dangerous Voltage" within the product's enclosure that
may be of sufficient magnitude to constitute a
risk of electric shock to humans.
The exclamanation point,within an equilateral
triangle is intended to alert the users to the presence of important operating and maintenance
(servicing) instructions in the literature accompanying the product.
Sicherheitsvorschriften
VORSICHT
UM ELEKTRISCHEN SCHLAG ZU
VERMEIDEN, KEINE FINGER ODER
GEGENSTÄNDE IN ÖFFNUNNGEN DES
GEHÄUSES STECKENN
WARNUNG: ZUR VERMEIDUNG VON FEUER
ODER ELEKRISCHEN SCHLÄGEN DAS GERÄT
NICHT MIT REGEN ODER FEUCHTIGKEIT IN
BERÜHRUNG BRINGEN
Erklärung der graphischen Symbole
Der Blitz mit nach untenzielendem Pfeil in einem
gleichseitigen Dreieck weist den Benutzer auf
das Vorhandensein einer unisolierten,
"gefährlichen Spannung" im Gehäuse hin, die
stark genug sein kann, einer Person einen
gefährlichen elektrischen Schlag zu versetzen.
Das Ausrufezeichen in einem gleichseitigen
Dreieck weist den Benutzer auf wichtige
Betriebs- und Wartungsvorschriften in den
beiliegenden Unterlagen des Gerätes hin.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC
SHOCK, DO NOT REMOVE THE COVER. NO USERSERVICEABLE PARTS INSIDE. REFER SERVICING
TO QUALIFIED SERVICE PERSONNEL
CAUTION
RISK OF ELECTRIC SHOCK:
OPEN ONLY IF QUALIFIED AS
SERVICE PERSONNEL
To reiterate the above warnings: servicing instructions
are for use by qualified personnel only. To avoid electric
shock, do not perform any servicing other than that contained in the Operation Instructions unless you are qualified to do so. Refer all servicing to qualified personnel.
VORSICHT
GEFAHR EINES ELEKTRISCHEN
SCHLAGES NICHT ÖFFNEN
VORSICHT! UM DAS RISIKO EINES
ELEKTRISCHEN SCHLAGES ZU VERMINDERN,
ABDECKUNG NICHT ENTFERNEN. KEINE
BENUTZER BEDIENUNGSTEILE IM INNERN.
BEDIENUNG NUR DURCH QUALIFIZIERTES
BEDIENUNGSPERSONAL.
VORSICHT
GEFAHR EINES ELEKTRISCHEN
SCHLAGES: NUR VON QUALIFIZIEREM
WARTUNGSPERSONAL ZU ÖFFNEN
Eindrigliche Warnung: Wartungsvorschriften dienen
nur der Benutzung durch qualifizieres Personal. Zur
Vermeidung eines elektrischen Schlages keine anderen als
die in den Betriebsvorschriften beschriebenen
Wartungsarbeiten ausführen, es sei denn Sie sind dafür
qualifiziert. Wartungsarbeiten sind nur von qualifiziertem
Wartungspersonal auszuführen.
2
Warning Messages 2
Table of Contents 3
ntroduction 4
I
Technical Specifications 5
Front Panel Features
Status LED's 6-7
Signal LED's 6-7
Output Attenuators 6-7
On/Off Switch 7
Rear Panel Features
AC Fuse 8
Output Connections 8
Standard Input Module
Output Mode Selector 8
Input Connections 9
Looping Outputs 9
Ground Lift Switch 9
Loudspeaker Controller Modules
C12 Loudspeaker Controller Module 10
Input Connections 10
Output Connections 10
C22 Loudspeaker Controller Module 10
Output Connections 10-11
Input Connections 11
Ground Lift Switch 11
C22 Setup Switches 12
L20 Limiter Module
Looping Outputs 12
HPF Selectors 12
Input Connectors 12
Limit Set Switches 12
Output Mode Selector 13
Ground Lift Switch 13
P2850/P2950 OPERATION MANUAL
Table of Contents
Amplifier Set-Up and Operation 14
Cooling 14
Mounting 14
Wire Size 14
Performance Verification 14
System Block Diagrams
Without Controller Modules 15
With L20 Limiter Module 15
With C12 Controller Module 16
With C22 Controller Module 16
3
P2850/P2950 OPERATION MANUAL
Congratulations on your purchase of a Renkus-Heinz P2850 or P2950 dualchannel, professional, power amplifier.
Your Renkus-Heinz amplifier has been designed to provide years of trouble-free, high
performance operation. We hope you enjoy it.
Your amplifier may include a C12 or C22 loudspeaker controller module or a L20
Limiter Module in place of the standard dual channel input module (see pages 8 to 13
for details). The C12 and C22 controller modules are dedicated companions to a
specific Renkus-Heinz loudspeaker. They provide protection circuitry, electronic
crossover circuitry and response optimization for their associated loudspeakers.
The L20 is a limiter module with user adjustable limit and HPF controls. It is not
"loudspeaker specific" and allows the user to adjust the controls to suit his application.
Introduction
Caution: If your amplifier includes a C12 or C22, it is configured for use with a
particular loudspeaker model and should not be used with any other model. Use
of the wrong loudspeaker may result in loudspeaker damage.
Your Renkus-Heinz amplifier was completely tested and inspected before leaving our
factory and should have arrived in perfect condition. Please carefully inspect your
amplifier and its shipping carton for any noticeable damage, and if any damage is
found, immediately notify the shipping company.
Only the consignee may institute a claim with the carrier for any damage incurred
during shipping. Be sure to save the carton and all packing materials for the carrier's
inspection.
It is also a good idea to save the carton and packing material even though the amplifier arrived in good condition. If shipping the amplifer should ever be required, it
should be shipped only in its original factory packing.
Important:
Your Renkus-Heinz amplifier contains no user-serviceable parts and all service
should be referred to qualified service personnel. We recommend that it be returned
to the factory in its original packing carton if factory service is required.
4
Technical Specifications
P2850/P2950 OPERATION MANUAL
POWER OUTPUT RATINGS:
(20 Hz to 20 kHz < 0.1% THD)
FREQUENCY RESPONSE:
THD (at 1kHz) DISTORTION:
SMPTE IMD:
HUM & NOISE:
CROSSTALK:
INPUT SENSITIVITY:
INPUT IMPEDANCE:
VOLTAGE GAIN:
SLEW RATE:
DAMPING FACTOR:
POWER REQUIREMENTS:
P2850 P2950
500 watts/ch at 8 Ohms 800
750 watts/ch at 4 Ohms 1200
900 watts/ch at 2 Ohms 1600
1500 watts bridged (8 Ohm) 2400
1800 watts bridged (4 0hm) 3200
+0.0, -.5 dB, 20 Hz to 20 kHz
< 0.1% at rated power output (4 ohms)
< 0.015 %
-100 dB (referred to RPO @ 8 ohms,
20 Hz to 20 kHz
> 60 dB @ 400 Hz
1.4 V for RPO @ 8 ohms
20 K ohms, balanced
45 (P2850)
57 (P2950)
> 40 V/usec
>200 @ 8 ohms
120 VAC, 60 Hz (Domestic)
230 VAC, 50/60 Hz (Export)
1500 VA
FEATURES:
COOLING:
CONSTRUCTION:
FINISH:
FRONT CONTROLS:
REAR CONTROLS:
REAR PANEL CONNECTORS:
DIMENSIONS (H X W X D):
NET / SHIPPING WEIGHT:
ASSOCIATED EQUIPMENT:
Temperature, DC @ output, short circuit protection
Delayed turn-on with output muting
Subsonic and ultrasonic filters
Signal & Status LEDs
Dual front to rear, variable speed DC fans
All steel closed box construction;
3/16" aluminum face panel
Black (powder coat)
Output level attenuators, power on/off,
Stereo/mono/bridging mode selector
Ground lift switch
Inputs; 3-pin female XLR ( pin 2 +)
Outputs; 4-pin Neutrik Speakon
Looping (controller) output(s); 3-pin male XLR (pin 2 +)
5 1/4" H x 19" W x 18" D ( depth behind panel) (13.3 x 48.2
x 45.7 cm)
(P2850) 63/70 Lbs (28.6/31.7 kg)
(P2950) 368/75 Lbs (30.8/34 kg)
C12 & C22 plug-in loudspeaker controller modules
L20 plug-in limiter module
R-Control Remote Control & Supervision System
5
P2850/P2950 OPERATION MANUAL
Front Panel Features
Status LED's
Signal LED's
Output
Attenuator
1. Channel 1 Status (Prot/Pwr) LED
The Channel 1 Status LED glows green to indicate the amplifier is on and Channel 1 is
operating normally. It glows red to indicate that one or more of the amplifier Channel 1
protective circuits has been activated. The amplifier contains separate over-temperature, DC
on output and shorted-load protective circuitry for each channel. Whenever a fault is
detected, the offending channel is temporarily "shut down" and the status light turned red to
call attention to the problem. The channel will remain "off" until normal operating conditions are restored.
Note. The status LED is also controlled by the C12 & C22 controller and L20 limiter
modules and when one of these modules is included, the status LED will glow red when one
of these modules' protective circuits has been activated.
It is normal for the Status LED to glow red when the amplifier is first turned on. It will then
turn to a steady green as a sign that Channel 1 is on and operating satisfactorily.
2. Channel 1 Signal (Clip/Sig) LED
The Signal LED indicates the status of the amplifier's Channel 1 signal level. When it is off
(not glowing), it shows that no signal is being received. It glows green to indicate a normal
signal level and red as an indication that Channel 1 is being driven into clipping. Occasional
operation of the red "clip" indication (flickering of the red light) is an indication of optimum
system utilization. Extended illumination of the red "clip" indication is a sign the system is
being overdriven and shoud be avoided.
3. Channel 1 Output Attenuator
The Channel 1 Output Attenuator controls the gain of Channel 1 in all operating modes.
When it is turned fully clockwise, the amplifier will have its maximum rated voltage gain
and will deliver it rated output when driven by its rated input signal. As a general rule,
setting the attenuator in the full clockwise position provides maximum amplifier headroom;
setting the attenuators at a lower level maximizes the system signal/noise ratio.
Important - - When the amplifier is being operated in the bridge output mode, both the
Channel 1 and Channel 2 attenuators must be set in the same position to avoid a mismatch
in the signal level being sent to each channel.
6
P2850/P2950 OPERATION MANUAL
Front Panel Features
4. Channel 2 Status (Prot/Pwr) LED
The Channel 2 Status LED glows green to indicate the amplifier is on and Channel 2 is operating
normally. It glows red to indicate that one or more of the amplifier's Channel 2 protective circuits
has been activated. The amplifier contains separate over-temperature, DC on output and shortedload protective circuitry for each channel. Whenever a fault is detected in Channel 2, the channel
is temporarily "shut down" and the status light turned red to call attention to the problem. The
channel will remain "off" until normal operating conditions are restored.
Note. The status LED is also controlled by the C12 & C22 controller and L20 limiter modules and
when one of these modules is included, the status LED will glow red when one of these modules'
protective circuits has been activated.
It is normal for the Status LED to glow red when the amplifier is first turned on. It will then turn
to a steady green as a sign that Channel 2 is on and operating satisfactorily.
5. Channel 2 Signal (Clip/Sig) LED
The Channel 2 Signal LED indicates the status of the amplifier's Channel 2 signal level. When it
is off (not glowing), it shows that no signal is being received by Channel 2. It glows green to
indicate a normal signal level and red as an indication that Channel 2 is being driven into clipping. Occasional operation of the red "clip" indication (flickering of the red light) is an indication
of optimum system utilization. Extended illumination of the red "clip" indication is a sign the
system is being overdriven and shoud be avoided.
6. Channel 2 Output Attenuator
The Channel 2 Output Attenuator controls the gain of Channel 2 in all operating modes. When it
is turned fully clockwise, the amplifier will have its maximum rated voltage gain and will deliver
its rated output when driven by its rated input signal. As a general rule, setting the attenuator in
the full clockwise position provides maximum amplifier headroom; setting the attenuators at a
lower level maximizes the system signal/noise ratio.
Status LED's
Signal LED's
Output
Attenuator
7. Power On/Off Switch
This switch is used to turn power to the amplifier "on" and "off".
7
On/Off Switch
P2850/P2950 OPERATION MANUAL
Rear Panel Features
6
GROUND LIFT
ON OFF ON
7
LINK
Ch 2
8 9
INPUTS
10
LINK
Ch1
11
STEREO
PARALLEL BRIDGE
(CH 1)
Output
Connections
RISK OF ELECTRICAL SHOCK
T O REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK
D
O NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL
DO NOT OPEN
TO REDUCE THE RISK OF ELECTRICAL SHOCK
DO NOR REMOVE COVER (OR BACK)
NO USER SERVICEABLE PARTS INSIDE
POWER CONSUMPTION : 3500 VA
SERIAL NO.
MANUFACTURED IN EEC
cc
IRVINE, CA - U.S.A.
CH 2 OUT
STEREO 2 OHM. MIN.
1
BRIDGED MONO 4 OHM MIN.
2
CH 1 OUT
1. Channel 2 Output Connector
4-Pin Neutrik Speakon connector provides single-connector, quick-disconnect facilities for
Channel 2 on pins 1+ & 1-. Pin 1+ is considered the "hot" terminal while pin 1- is "common".
2. Bridge Output Connector
4-Pin Neutrik Speakon connector provides single-connector, quick-disconnect facilities for the
amplifier's Bridge output on pins 1+ & 1-. Both Pins 1+ and 1- are considered "hot" and
should not be grounded.
3. Channel 1 (and 2) Output Connector
4-Pin Neutrik Speakon connector provides single-connector, quick-disconnect facilities for both
Channel 1 and Channel 2 outputs. The Channel 1 output is on pins 1+ & 1- and the Channel 2
output on pins 2+ & 2-. Pins 1+ & 2+ are considered "hot" while pins 1- & 2- are "common".
MO
11
Note: If your amplifier has a C12 or C22 controller module or L20 limiter module, instead of the
standard input module shown in the above drawing, please turn to pages 10 and 11.
4. AC Power Cord
Before connecting the amplifier, check the AC voltage requirement and make certain the
unit is connected to the proper voltage. Failure of the unit will result if a 120 volt amplifier
is connected to a 220 volt power line.
Circuit Breaker
5. Line Protect (Circuit Breaker)
Circuit breaker and associated "Line Protect" switch provide overall protection; must be
manually reset.
Standard Input Module
Ground Lift
Switch
6. Ground Lift Switch.
The Ground Lift switch is used to separate the signal ground circuit from the amplifier
ground circuit and thus, eliminate hum induced by ground loops.
In the left "ON" position, the signal ground is electrically disconnected from the amplifier
ground circuit (the chassis).
In the center "OFF" position, the input signal ground is electrically connected to the
amplifier ground circuit (the chassis).
In the right "ON" position, an AC connection is provided between the signal ground and the
amplifier ground circuit (the chassis).
8
N
T
STEREO
PARALLEL BRIDGE
(CH 1)
P2850/P2950 OPERATION MANUAL
Rear Panel Features
AL SHOCK
EN
R ELECTRICAL SHOCK
TO RAIN OR MOISTURE
ECTRICAL SHOCK
ER (OR BACK)
PARTS INSIDE
SERVICE PERSONNEL
: 3500 VA
ED IN EEC
IRVINE, CA - U.S.A.
CH 2 OUT
STEREO 2 OHM. MIN.
BRIDGED MONO 4 OHM MIN.
2
CH 1 OUT
3
MODEL P-2950
LINE PROTECT
117 V ~
5
4
7. Channel 2 "Looping Output" Connector
Male 3-pin XLR type "looping output" connector for Channel 2 used to "loop through" to
additional amplifiers.
8. Channel 2 Audio Input Connector
Female 3-pin XLR type input connector for Channel 2. The input is electronically balanced.
We recommend the use of pin 2 as "hot" and pin 3 as "neutral". Pin 1 is chassis ground.
When the amplifier is connected to a balanced source, the shield may either be lifted or
connected at the source end. The choice should be made on the basis of minimum hum.
With an unbalanced source, connect the signal to pin 2 and source ground to pin 3 (connecting the signal to pin 3 is not recommended as this will cause a 180 phase inversion at
the amplifier outputs. Note: Improper operation results when only pin 2 or only pin 3 and
pin 1 (ground) are used for an unbalanced input.
"Looping"
Outputs
Input
Connections
9. Channel 1 Audio Input Connector.
Female 3-pin XLR type input connector for Channel 1. Refer to 6 above for details.
10. Channel 1 "Looping Output" Connector
Male 3-pin XLR type "looping output" connector for Channel 1 used to "loop through" to
additional amplifiers.
11. Stereo - Parallel - Bridge Output Mode Selector
The Output Mode Selector allows the amplifer to be operated in 3 different output modes.
Output
Mode Selector
In the Stereo mode, the two channels operate independently, just as they do in a stereo
amplifier: signals fed into the two amplifier inputs are amplified separately and delivered
in phase to outputs 1 & 2. The output levels are controlled separately by the front panel
mounted attenuators.
In the Parallel mode, input 2 is disabled and the two amplifier channels operate in parallel
from a single input signal fed into the Channel 1 input. This eliminates the need to install a
jumper cable to operate the amplifier channels in parallel. The outputs are separate and in
phase and both input attenuators are active to permit different level settings for each
channel.
In the Bridge mode, a single signal is fed into the Channel 1 input which drives both output
channels in tandem. The output is delivered to the Bridge Output connector. This mode
allows the two amplifier outputs to be strapped together ( "bridged") to produce a single
output with double the power capabilites of a single channel. Input #2 is disabled. Both
input attenuators are active and must be set to the same level. Note that in bridge mode both
sides of the output should be considered hot and should not be grounded.
9
P2850/P2950 OPERATION MANUAL
Loudspeaker Controller Modules
MODEL
C12
cc
C12 Controller Module
The C12 loudspeaker controller module is a single input, dual output controller designed
for use with active 2-way loudspeakers (or 3-way loudspeakers set up for bi-amp operation)
in single channel (mono) systems. In this application, it provides crossover, protection and
response shaping. It is also often used as a controller to provide protection and response
shaping for either subwoofers or passive 2-way loudspeakers.
Input
Connections
1. Audio Input Connector
Female 3-pin XLR type input connector. The input is electronically balanced. We recommend the use of pin 2 as "hot" and pin 3 as "neutral". Pin 1 is chassis ground. When the
amplifier is connected to a balanced source, the shield may either be lifted or connected at
the source end. The choice should be made on the basis of minimum hum.
1
PIN 1 = GND
PIN 2 = +
PIN 3 = -
2
SUB/LF OUT FR/HFINPUT
3
RENKUS-HEINZ
MADE IN USA
With an unbalanced source, connect the signal to pin 2 and source ground to pin 3 (connecting
the signal to pin 3 is not rcommended as this will cause a 180 phase invervion at the amplifier
outputs). Note: Improper operation results when only pin 2 or only pin 3 and pin 1 (ground) are
used for an unbalanced input.
Output
Connections
2. SUB/LF "Output" Connector
Male 3-pin XLR type controller output connector for the SUB/LF channel; used to drive additional amplifiers.
3. FR/HF "Output" Connector
Male 3-pin XLR type controller output connector for the FR/HF channel; used to drive additional
amplifiers.
Note: When the processed controller outputs are used to drive additional amplifiers, it is
imperative that the source amplifier's level controls are set at the same or a higher level. Otherwise, the protection feature is lost for the other amplifiers.
C22 Controller Module
The C22 loudspeaker controller module is a dual input, dual output controller designed for use in
stereo systems having either passive loudspeakers or subwoofers. In these systems, it provides
protection for the loudspeakers or subs, as well as high & low pass filters and response shaping.
1. Channel 2 "Processed Output" Connector
Male 3-pin XLR type controller "processed output" connector for Channel 2; provides a
Output
"looping" controller processed output for use in driving additional amplifiers.
Connections
3. Channel 2 "FR/HPF Output" Connector
Male 3-pin XLR type controller output connector for the FR/HPF channel; used to drive
additional amplifiers. An internal selector switch determines whether this connector
10
1 32 5 6 74
P2850/P2950 OPERATION MANUAL
Loudspeaker Controller Modules
MODEL
C22
CH 2 OUTPUTS
PROCESSED LOOPING / HPF
LOOPING / HPF
CH 2 INPUT
PIN 1 = GND
PIN 2 = +
PIN 3 = -
GROUND
CH 1 INPUT
CH 1 OUTPUTS
RENKUS-HEINZ
MADE IN USA
PROCESSED
provides a full-range "looping" output or a processed band-limited "high pass filter"
output. Refer to Selector Switches on page 12 for further information.
3. Channel 2 Audio Input Connector
Female 3-pin XLR type input connector. The input is electronically balanced. We recommend the use of pin 2 as "hot" and pin 3 as "neutral". Pin 1 is chassis ground. When the
amplifier is connected to a balanced source, the shield may either be lifted or connected at
the source end. The choice should be made on the basis of minimum hum.
With an unbalanced source, connect the signal to pin 2 and source ground to pin 3 (connecting the signal to pin 3 is not rcommended as this will cause a 180 phase inversion at the
amplifier outputs). Note: Improper operation results when only pin 2 or only pin 3 and pin
1 (ground) are used for an unbalanced input.
4. Ground Lift Switch.
The Ground Lift switch is used to separate the signal ground circuit from the amplifier ground
circuit and thus, eliminate hum induced by ground loops.
Input
Connections
Ground Lift
Switch
In the right position, the input signal ground is electrically connected to the amplifier ground
circuit (the chassis).
In the left position, only an AC connection is provided between the signal ground and the
amplifier ground circuit (the chassis).
5. Channel 1 Audio Input Connector.
Female 3-pin XLR type input connector for Channel 1. Refer to 3 above for details.
6. Channel 1 "FR/HPF Output" Connector
Male 3-pin XLR type controller output connector for the FR/HPF channel; used to drive additional amplifiers. An internal selector switch determines whether this connector provides a fullrange "looping" output or a processed band-limited "high pass filter" output. Refer to Selector
Switches on page 12 for further information.
7. Channel 1 "Processed Output" Connector
Male 3-pin XLR type controller "processed output" connector for Channel 2; provides a
"looping" controller processed output for use in driving additional amplifiers.
Note: When the processed controller outputs are used to drive additional amplifiers, it is
imperative that the source amplifier's level controls are set at the same or a higher level.
Otherwise, the protection feature is lost for the other amplifiers.
11
Input
Connections
Output
Connections
P2850/P2950 OPERATION MANUAL
Loudspeaker Controller Modules
Looping/HPF Selector
Switches
C22 Setup
Switches
sw 2
Filtered
sw 1
PK22-xxx Kit
sw 3 sw 3
C22 Controller Module Physical Layout
sw 1
Filtered
PK22-xxx Kit
sw 2
Stereo Bridged
Stereo/Bridged
Jumper Plug
The C22 Loudspeaker Controller Module has several selector switches and a Stereo/
Bridging Jumper plug that are accessible by removing the module from the amplifier. The
location of these controls is shown in the above outline drawing.
The Looping/HPF switches control the signals to the Looping/HPF output connectors. In the
Filtered position, the associated output connector is connected to the output of that
channel's high pass filter. In the other position, the connector parallels that channel's input
connector and servers as a "looping" output. The HPF setting is used to deliver a bandlimited signal to an additional amplifier for "non-overlap" operation (refer to the system
wiring diagram on page 16 for further information).
L20 Limiter Module
Looping
Outputs
HPF Selectors
The Stereo/Bridging Jumper plug is used to "bridge" the two output channels together to
provide a single output with twice the power capabilities of a single channel. Note that the
Jumper Plug is located under the right PK22-xxx kit, which must be removed (unplugged)
to gain access to the Jumper Plug.
The switches identified as sw 1, sw 2 and sw 3 are used to configure the C22 for specific
loudspeakers. Additional information on these switches can be found in the C22 Operation
Manual.
The L20 is a dual-channel limiter module. It is not loudspeaker specific and is provided with
user adjustable limit and HPF (high pass filter) controls (refer to drawing on next page). It is used
to provide limiting on both amplifier channels (loudspeaker protection) plus low frequency
rolloff.
1 & 6. "Looping" Audio Output Connectors
These male 3-pin XLR type connectors are wired in parallel with the input connectors and
provide unprocessed "looping" Channels 1 and 2 outputs. They allow "looping" through to
additional amplifiers.
2 & 5. HPF Selector Switches
Three position switches allow the Channel 1 and 2 low frequency rolloff points to be set at
either 30 Hz, 60 Hz or 100 Hz to protect small loudspeakers from over excursion damage.
12
P2850/P2950 OPERATION MANUAL
Loudspeaker Controller Modules
32 5 64
INPUTOUTPUT
STEREO
PARALLEL
PIN 1 = GND
PIN 2 = +
PIN 3 = -
BRIDGE
GROUND
X
98 10
OUTPUTINPUT
CH 1
HP FILTER
100Hz
60Hz
30Hz
LIMIT
100 200 350
(400) (800) (1400)
BRIDGE
RENKUS-HEINZ
MADE IN USA
MODEL
L20
1
(400) (800) (1400)
BRIDGE
CH 2
HP FILTER
60Hz
LIMIT
100 200 350
7
100Hz
30Hz
3 & 4. Audio Input Connectors
Female 3-pin XLR type input connectors for Channels 1 and 2. Refer to section 6 on page 9
for wiring details.
7 & 10. Limit Set Switches
Three position switches allow the Channel 1 and 2 maximum output levels to be set at either
100, 200 or 350 watts into 8 ohms (400, 800 or 1400 watts in bridge mode).
8. Stereo - Parallel - Bridge Output Mode Selector
The Output Mode Selector allows the amplifer to be operated in 3 different output modes.
Input
Connectors
Limit Set
Switches
Output Mode
Selector
In the Stereo mode, the two channels operate independently, just as they do in a stereo
amplifier: signals fed into the two amplifier inputs are amplified separately and delivered in
phase to outputs 1 & 2. The output levels are controlled separately by the front panel
mounted attenuators.
In the Parallel mode, input 2 is disabled and the two amplifier channels operate in parallel from a
single input signal fed into the Channel 1 input. This eliminates the need to install a jumper cable
to operate the amplifier channels in parallel. The outputs are separate and in phase and both input
attenuators are active to permit different level settings for each channel.
In the Bridge mode, a single signal fed into the Channel 1 input, drives both output channels in
tandem and the output is delivered to the Bridge Output connector. This mode allows the two
amplifier outputs to be strapped together ( "bridged") to produce a single output with double the
power capabilites of a single channel. Input #2 is disabled. Both input attenuators are active and
must be set to the same level. Note that in bridge mode both sides of the output should be considered hot and should not be grounded and that the Limit and HPF switches should be set in the
same position.
9. Ground Lift Switch.
The Ground Lift switch is used to separate the signal ground circuit from the amplifier ground
circuit and thus, eliminate hum induced by ground loops.
In the left position, the signal ground is electrically connected to the amplifier ground circuit
(the chassis). In the center position, the input signal ground is electrically disconnected
from the amplifier ground circuit (the chassis).
Ground Lift
Switch
In the right position, an AC only connection is provided between the signal ground and the
amplifier ground circuit (the chassis).
13
P2850/P2950 OPERATION MANUAL
Amplifier Setup and Operation
Mounting
Cooling
Wire Size
The P2850 and P2950 amplifiers are designed to be mounted in standard 19" racks. They
have 4 front panel mounting screws. Because of their depth and weight it is imperative that
the amplifier be supported at the rear in any portable application.
Both amplifiers are fan cooled and it is important that an ample supply of air is provided at
the front of the amplifier and a free air exhaust space is provided at the rear of the amplifier.
The internal fan provides adequate cooling when the rack has an open back and the front is
not obstructed. Closed back racks may need to be pressurized and provided with an exhaust
fan to ensure adequate air movement.
Multiple amplifiers may be stacked directly on top of each other. Their is no need to separate
them with a blank (spacer) panel. Keep in mind that almost all amplifiers radiate a 50/60 Hz
magnetic hum field from their power transformers. It is prudent to provide at least one rackspace between any signal processing equipment and the nearest amplifier to reduce the possibility
of induced hum.
The size of the speaker wiring needed depends on the length of the cable. We generally recommend the use of 12 AWG for c!ables up to 30 meters (approximately 100 feet) in length. The
following table shows the signal loss in 30 meters of cable driving a 4 ohm load:
Wire Gauge (AWG) 10 12 14 16 18
Signal Loss (dB) .44 .69 1.07 1.65 2.49
Using higher wattage amplifiers than actually needed is acceptable when controller modules are
used as the controller will keep peak power levels within the acceptable limits for the associated
loudspeaker(s).
Verification of Proper Operation
Before applying power to the system, trace and verify all connections.
Caution: Operating the System at full level can damage your hearing. Wear ear protectors and
do not position yourself in front of the loudspeakers.
Make certain all the Mode selector switches are set in the desired mode and that outputs are
properly connected. Loudspeaker damage may occur if, for example, the Sub outputs are
connected to the high frequency drivers and not to the Subs!
Set the power amplifier gain controls to their minimum position.
Turn on the power amplifiers and slowly turn the amplifier level controls to their maximum
position one at a time. While you are doing this, verify that as the amplifier gain is increased the
appropriate response is obtained (i.e. the sub channel is connected to the subwoofers). Moderate
level audio should be heard from the loudspeakers.
Gradually increase the signal level while observing the Signal LED's. As the level increases they
should begin to flicker red. As the level continues to increase they will be on for longer periods
of time. Do not operate the system at a level where the protection LED’s are illuminated
continuously.
If as you are increasing the level, you hear a sudden loss of one channel and see illumination of a red Status LED, this indicates one of the amplifiers protective circuits has been
activated. Turn the amplifier off, reduce the gain and then turn the amplifier on again.
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P2850/P2950 OPERATION MANUAL
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P2850/P2950 OPERATION MANUAL
19201 Cook Street, Foothill Ranch, CA 92610-3501
Tel: 949-588-9997 Fax: 949-588-9514 E-mail: Sales@renkus-heinz.com W eb: www .rh.com
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