Precision Power PowerClass PC4200 User manual

POWERCLASS™
PC4200 / PC4400 / PC4800 / PC6600 OWNER’S MANUAL
•CONGRATULATIONS
CONTENTS
(click on a topic to view)
•FEATURES / SPECIFICATIONS
•FEATURES / SPECIFICATIONS (cont.)
•INSTALLATION
•WIRING
•WIRING (continued)
•POWER / GROUND
•POWER, GROUND, and REMOTE
•SPEAKER WIRING
•QBASS / QBASS REMOTE
•CROSSOVER OPERATION
•FREQUENCY DETENT CHARTS
•INPUT COMBINE / GAIN
•THERMAL MANAGEMENT
•TROUBLE SHOOTING
•SYSTEM DIAGRAM ONE /TWO
•SYSTEM DIAGRAMTHREE
•SYSTEM DIAGRAM FOUR
•BRIDGING •SYSTEM DIAGRAM FIVE
•REAR ENDPLATE DIAGRAMS •SYSTEM DIAGRAM SIX
•FRONT ENDPLATE PC4200 / PC4400
•FRONT ENDPLATE PC4800
•BLOCK DIAGRAM 4200 / 4400
•BLOCK DIAGRAM 4800
•FRONT ENDPLATE PC6600 •BLOCK DIAGRAM 6600
•INPUTS •WARRANTY

for choosing PrecisionPower audio epuipment. At PrecisionPower we
proudly design, engineer and manufacture audio products at our facility in
Phoenix, Arizona. Our award winning engineering team utilizes innovative
technology to consistently deliver Absolutely State of the Art
TM performance,
sound quality, reliability, and value. This PrecisionPower product reflects
our commitment to offer you unparalleled versatility and quality for years of
dependable service and listening enjoyment.
Service
Do not attempt to service PrecisionPower products yourself.
Performing exploratory surgery on your audio equipment yourself
will void the warranty. Many parts of your PrecisionPower gear
are custom built to our specifications. Our factory parts are not
made available to anyone else nor are they for sale. Our goal
is to make sure that your PrecisionPower product will always
sound as good as the day it was purchased. Contact your
authorized PrecisionPower dealer about obtaining any warranty
service through PrecisionPower .(See Warranty insde back cover)
FOR YOUR RECORDS:
Model
Serial Number
Purchase Date
Caution!
The extended use of a high powered audio system may
result in hearing loss or damage. While PrecisionPower
systems are capable of "Concert Level" volumes with
incredible accuracy, they are also designed for you to
enjoy at more reasonable levels all of the sonic subtleties
created by musicians. Please observe all local sound
ordinances.
Congratulations and thank you.....
BACK TO CONTENTS

BACK TO CONTENTS
Your new amplifier incorporates some or all of the following features:
Adaptive MOSFET Switching Power Supply
Fully Complementary Darlington Output Stage
AP III Protection Circuitry (PC4200, PC4400, PC6800)
AM IV Protection Circuitry (PC4800)
QBASS™ Bass Boost (PC4200, PC4400)
QBASS PLUS™ (PC4800, PC6600)
QBASS REMOTE™ Compatible (PC4800, PC6600)
PowerLock Speaker and Power Wire Connectors
Detented, Variable 3-way Internal Crossover
Non-Fading Sub Channel
Balanced Differential Input Stage
High Voltage Input Capability with Input Attenuation Switch
Gold Plated RCA Input and Output Connectors
Mixed Mono/Stereo Operation
3Year Warranty when installed by an Authorized PrecisionPower Dealer
Completely Designed And Handcrafted In The USA
Specifications
Power Bandwidth: 4.5 Hz - 100 kHz
Total Harmonic Distortion: 0.02 %
Input Topology: Differential
Input Sensitivity: 150mv - 12 volts RMS
Input Impedance: 10k Ohms
Load Impedance (stereo) 2 - 8 Ohms
Load Impedance (bridge) 4 - 8 Ohms
Supply Voltage 11 - 15 volts
Damping Factor >500
Slew Rate >50 V/µS
Idle Current: PC4200 / PC4400 - 1.5 Amps
PC4800 - 3.0 Amps
PC6600 - 2.0 Amps
Continuous Output Power
PC4200 PC6600
25 WRMS x 4 @ 4Ωper channel 50 WRMS x 6 @ 4Ωper channel
50 WRMS x 4 @ 2Ωper channel 100 WRMS x 6 @ 2Ωper channel
100 WRMS x 2 @ 4Ωbridged 200 WRMS x 3 @ 4Ωbridged
PC4400 PC4800
50 WRMS x 4 @ 4Ωper channel 100 WRMS x 4 @ 4Ωper channel
100 WRMS x 4 @ 2Ωper channel 200 WRMS x 4 @ 2Ωper channel
200 WRMS x 2 @ 4Ωbridged 400 WRMS x 2 @ 4Ωbridged
FEATURES / SPECIFICATIONS
1

BACK TO CONTENTS
QBASS
0
+18
Q
BASS REMOTE
™
Designed and handcrafted in the USA
™
Dimensions
PC4200
Length - 12.22"
Height - 2.25"
Width - 8.9"
Crossover Specifications
PC4200 / PC4400
Front - 12dB/Octave, Detented High Pass 20-5kHz
Rear - 12dB/Octave, Selectable Detented High or Low Pass 20-5kHz
RCA Out-Summed Mono 24dB/Octave, Linkwitz-Riley Low Pass, 90Hz
QBASS ™ on Rear Channel
PC4800
Front - 12dB/Octave, Detented High Pass 20-5kHz
Rear - Choice of 12dB/Octave Detented High Pass 20-5kHz, or
Summed Mono 24dB/Octave, Linkwitz-Riley Detented Low Pass 44-315Hz
RCA Outputs will be the opposite of your Rear Crossover choice.
QBASS PLUS ™ on Rear Channel
PC6600
Front - 12dB/Octave, Detented High Pass 20-5kHz
Rear - 12dB/Octave, Detented High Pass 20-5kHz
Sub-Summed Stereo 24dB/Octave, Linkwitz-Riley Low Pass at 90Hz
QBASS PLUS ™ on Sub Channel.
FEATURES / SPECIFICATIONS
Q BASS
™
and Q BASS PLUS
™
Specifications
QBASS™ (PC 4200, PC4400, and PC 6600)
Up to 12dB of Boost centered at 40Hz, with a Q-Factor of 2.
QBASS PLUS™ (PC 4800)
Up to 18dB of Boost with selectable center frequency at 30Hz, 36Hz,
44Hz or 60Hz.Selectable Q of 2 or 4.Optional remote mounted
Boost Control.
Optional QBASS REMOTE
™
(PC 4800)
This boost control can be mounted
in the dash and will supersede the
boost control on the amplifier endplate.
Optional QPORT
™
expansion module
allows one QBASS REMOTE
™
to
operate multiple amplifiers.Each
QPORT
™
has outputs for four amplifiers
as well as another QPORT
™
for greater
expansion. See your authorized PrecisionPower
dealer for more information!
2
PC6600
Length - 19.72"
Height - 2.25"
Width - 8.9"
PC4800
Length - 23.72"
Height - 2.25"
Width - 8.9"
PC4400
Length - 13.72"
Height - 2.25"
Width - 8.9"

BACK TO CONTENTS
3
Tools/Parts needed for Installation (not supplied)
Small flat blade screwdriver
Phillips Screwdriver (#2 or medium sized)
Wire cutters
Wire strippers
4 - #6 round head screws, and 1 - #8 sheet metal screw
(or nut, bolt, and star washer)
2- Ringconnectors(largeenoughto accommodateyourmethodofgrounding)
In-line fuse or circuit breaker - see fuse chart below
Power and ground wire - see Power Wire Calculator on page 4
Speaker wire - 16 gauge or larger
Grommets (sized to work with the power wire you plan to use
in your installation)
Tube of silicone sealant
INSTALLATION
You will need to install an in-line fuse or circuit breaker in the power
wirewithin 18" of thebattery.This fuse or circuit breaker is to protect
your vehicle from fire in case the power wire shorts to the vehicle
body. If you are only using one amplifier, use the fuse rating indicated
in this chart. If you are using more than one amplifier, add up the fuse
ratings for all the amplifiers.This sum is the rating for your main fuse or
circuitbreaker.Usea powerdistributionblockorfusenearyouramplifiers
with the appropriate fuse for each individual power wire.
Fuse requirements
Amplifier Maximum Fuse Rating
PC4200 40 Amp
PC4400 60 Amp
PC4800 80 Amp
PC6600 80 Amp

BACK TO CONTENTS
The following is a basic formula to be used as a guide to determine current
draw. A 50% amplifier efficiency rating is used as an average.Your new
POWERCLASS
™amplifier is more efficient, other amplifiers will probably
be less. This formula is to be used as a guideline. Using wire of a larger
gauge can only improve the current transfer of your system. Do not use
smaller gauge wire.
Total RMS output x 2 = Total Input Wattage
Total Input Wattage = Current Draw (in Amps)
Supply Voltage
Example:A POWERCLASS
™4400 amplifier has four channels at 50 watts
RMS per channel into 4 Ohms (50 x 4 = 200).You would use the
formula in the following way:
200W x 2 = 400W
400W = 33.3A Total current draw.
12V
If the same amplifier is driven into a 2 Ohm stereo or 4 Ohm mono load,
doubleit's4OhmRMSrating.All POWERCLASS
™amplifierswilleffectively
double their power at this load.
100W x 4 x 2 = 800W
800W = 66.6A Total current draw.
12V
If you are using more than one amplifier, add up the total current draw
for all of them and choose the appropriate gauge based on the grand total.
Power Wire Calculator
Recommended MINIMUM Gauge
Total Current Draw Length Of Wire To Be Run
( in Amps) Upto4ft. 4 to 7ft. 7 to 10ft. 10 to 13ft. 13 to 16ft. 16 to 19ft. 19 to 22ft. 22 to 28ft.
0-20 14 12 12 10 10 8 8 8
20-35 12 10 8 8 6 6 6 4
35-50 10 8 8 6 6 4 4 4
50-65 8 8 6 4 4 4 4 2
65-85 6 6 4 4 2 2 2 0
85-105 6 6 4 2 2 2 2 0
105-125 4 4 4 2 2 0 0 0
125-150 2 2 2 2 0 0 0 00
(
NOTE: The ground wire should be the same gauge as the power wire.
4
WIRING

BACK TO CONTENTS
Before beginning, disconnect the negative (-) terminal of the
battery prior to working on the positive (+) terminal to prevent
a short to ground.This is important, unless you want to spend
the rest of your life with a nickname like "Sparky," or "Smokey."
Reconnect the negative terminal only after all connections have
been made.
5
Warning!
Fuse must be installed within 18" of battery
eject
VOLUME
BASS TREBLE
RIGHT
LEFT
BALANCE TRACK
REVERSE
FOWARD
1234
876
5
PPI MAR KET ING DPT
Trk 1
Fuse must be
installed within
18" of battery
Drill a hole in the firewall
and use a rubber grommet
to keep wire from shorting.
Run the cables under the
carpet near the side of the
vehicle. Be careful not to
drill or screw into the wires
when you replace the trim.
Run signal cables (RCAs)
and remote turn-on lead
down the opposite side of
the vehicle of the power
wire to avoid radiated noise.
Firmly attach Amp
Ground Wire to solid
metal (see page 6).
Avoid sharp edges that
could chafe through the
insulation.
Positive
Battery
Terminal
Factory Ground wire may
need to be replaced if it is
frayed or broken.
For systems over 300 watts,
add a ground cable from the
amp to the battery
(see page 6).
WIRING

BACK TO CONTENTS
Grounding
Locate an area near the amplifier(s) that is metal and clean an area
about the size of a quarter to bare metal. Inspect the area around
and underneath to be sure you won't drill into wires, brake or fuel lines.
Drill a pilot hole in the middle of this area.Terminate the ground wire
with a ring connector and attach it to the bare metal using a #8 sheet
metal screw and washer or preferably, a bolt, nut and a star washer
(not supplied).We suggest crimping and soldering this connection.
After the connection is complete, coat the area (on both sides) with
silicone or some similar material to prevent rust from developing on
the bare metal.
If your grand total current draw is over 50 amps (or total output
power is over 300 watts), you should run a ground wire beside
your power wire from the battery to the amplifier(s) in addition
to your regular ground wire. Keep the ground and power wires
as close together as possible, and use the same gauge wire for both.
This will ensure that you have a good ground path, and may eliminate
such potential problems as engine noiseand overheated amplifiers.
Charging System Considerations
If your grand total current draw is over 100 amps (or total output
power is over 600 watts), you are probably exceeding the capability
of your charging system.Dimming lights and fluctuating voltage are
solid indicators that you need to upgrade your alternator, battery
(or go to multiple batteries), or both.
Keep in mind that your amplifiers simply convert electrical energy
to acoustical energy, and any electrical deficiency will compromise
the performance of your sound system.
For more information about charging system upgrades, see your
local authorized PrecisionPower Dealer or call the PrecisionPower
technical support office at 1-800-62POWER .
6
POWER / GROUND

BACK TO CONTENTS
7
POWER / GROUND and REMOTE
Once you have run both the power and ground wires, it's time
to connect the cables to the amplifier. Cut off excess wire and,
using wire strippers, strip the ends of the power and ground
cables approximately 1/4 inch.Locate the PowerLock power
and ground connector (supplied).With a small flat bladed screw
driver, loosen the screws before attempting to insert the cables.
Insert the wires into the appropriate hole, and tighten the
screws. Once the wires are secure, the PowerLock may be
plugged into the amplifier.The Power/Ground PowerLock will
accommodate 6 gauge wire for the PC4200 / PC4400 , and 4 gauge
wire for the PC4800 and PC6600 .
Remote turn-on
Your head unit should have a lead marked 'remote' or 'power
antenna' which will be used to turn on your amplifier. Extend
this lead through your vehicle along with your RCA signal wires.
Strip 1/4 inch of insulation off the wire and insert the end into
the center terminal of the 5-pin speaker/remote PowerLock.
Power/Ground PowerLock
Connect to Amplifier
Fastening screws
Power wires

BACK TO CONTENTS
Using 16 gauge or larger, run the speaker wires from the
amplifier location through the vehicle to the speakers.Observe
the same precautions for routing these wires that you followed
for running the power and remote turn-on wires.Cut off excess
and, using wire strippers, strip 1/4 inch of insulation. Locate
the speaker/remote turn-on PowerLock connector. Loosen the
four outer screws on the underside of the connector and insert
the front ( PC4200, PC4400 and PC4800 ) or sub ( PC6600 )
speaker leads into the end.Check to be sure you've maintained
proper polarity before securing each wire.
8
SPEAKER WIRING
Speaker/Remote PowerLock
For the rear channels, locate the four terminal speaker
PowerLock connector. (For PC650, the front channel also uses
a four terminal PowerLock connector.) On 4 and 6 channel
PowerClass Amplifiers, all speaker PowerLocks plug into the
amplifier with the screws facing up. Loosen the screws on the
top of the blocks and insert the stripped ends of the speaker
wires into the end. Double check polarity, secure each wire by
tightening the screws, and plug the PowerLock connector into
the amplifier with the screws on top.
Right Speaker negative
Right Speaker positive
Left Speaker positive
Left Speaker negative
Speaker Power Lock Connector
Right Speaker negative
Right Speaker positive
Remote turn on
Left Speaker positive
Left Speaker negative
Speaker Power Lock Connector

BACK TO CONTENTS
Bridging
Any or all pairs of channels (front, rear or sub) on your POWERCLASS
™
multi channel amplifier are capable of being bridged into a 4 ohm mono
output without switches or bridging modules.This feature permits
the creation of a mono channel for a subwoofer or center channel.
Deriving the mono channel is accomplished by using the left channel
positive wire of the pair as the positive speaker wire and the right
channel negative wire as the negative speaker wire.You should always
be working with the wires of a single PowerLock speaker connector
when bridging a pair of channels.
NOTE: It is important that a minimum 4 ohm impedance is observed.
If the impedance drops significantly below 4 ohms while the amplifier
is wired in the bridged configuration, the amplifier's protection circuitry
may engage.
Mixed Mono Output
The ability to run stereo speakers while simultaneously running
a mono output from the same channel pair is accomplished by
running the stereo speakers normally and tapping into the appropriate
wires for the "mixed mono" channel (left channel positive for the
positive speaker wire and right channel negative for the negative
speaker wire).Total speaker impedance should be no lower than
2 ohms on the stereo channels and 4 ohms on the mono channel.
NOTE: Passive crossovers must be used for "mixed mono"
operation.Choose a low pass crossover around 100Hz for your
subwoofer, then choose a high pass crossover for your stereo
channels.The high pass crossover must be at the same or slightly
higher frequency than the low pass crossover to maintain the
correct impedance.See your PrecisionPower dealer or call
1-800-62POWER for more information about passive crossovers.
BRIDGING
9

BACK TO CONTENTS
-
+
POWER / MUTE
Designed and Handcrafted in the U.S.A.
QBASS
0
+ 18
QBASS
REMOTE
-
+
POWER / MUTE
Designed and Handcrafted in the U.S.A.
QBASS
0
+ 18
QBASS
REMOTE
-
+
POWER / MUTE
Designed and Handcrafted in the U.S.A.
10
ENDPLATE DIAGRAMS
POWER / GROUND / Q BASS
™
231
23
1
1
3
5
6
5
6
7
PC4400
PC4800
PC6600
1. POWER / GROUND PowerLock
After you have securely connected your power and ground wires, plug in the
Power / Ground PowerLock connector here.
2. COOLING VENTS (see page 18).
3. POWER / MUTE indicator
A green light indicates that the amplifier is on, a red light indicates that the amplifiers
muting circuits are engaged.
4. POWER indicator
A green light indicates that the ampilfier is on.
5. QBASS™Level
Turn this control clockwise to boost the Q BASS PLUS
™circuit by up to 18dB.
6. QBASS REMOTE™ plug in
Plug in the data cable from the optional Q BASS REMOTE
™dash mount level control here.
(This will bypass the amplifier's on board Q BASS
™control)
7. FORCED AIR INTAKE VENTS (see page 18 and 19).
2
PC4200
-
+
POWER
Designed and Handcrafted in the U.S.A.
241

BACK TO CONTENTS
FRONT
L - L + R E M R + R -
REAR
L - L + R + R -
OUTPUTS L / R
FRONT INPUTS L / R
REAR
GAIN QBASS
REAR
HP/LP
FRONT HP FREQ.
REAR XOVER FREQ.
L R
REAR INPUTS -12dB COMBINE
FRONT
GAIN
11
ENDPLATE DIAGRAM
4200 / 4400
1
1. REAR HP/LP switch
This switch is used to select whether the amplifier will provide a high
pass (switch in) or low pass (switch out) signal to the rear speakers.(see page 16).
2. REAR GAIN
Use this control to match the output level of the head unit to the rear channel of
the amplifier (see page 18).
3. QBASS™Control
Rotate clockwise to boost up to 12dB at 40Hz (see page 15).
4. FRONT GAIN
Use this control to match the output level of the head unit to the front channel of
the amplifier (see page 18).
5. COOLING VENTS (see page 18).
6. SPEAKER/REMOTE CONNECTOR
After connecting remote and speaker wires, plug in the PowerLock
connectors here (see pages 7-9).
7. REAR XOVER FREQ.
Use this control to adjust the rear crossover frequency from 20Hz to 5kHz (see page 16).
8. REAR INPUTS
Plug in the rear RCA leads from your head unit here (see page 14).
9. -12dB For use with high level inputs (4V up to 12V).Push this switch
in to attenuate the input by 12dB (see page 14).
10. COMBINE
Push this switch in to connect the rear channels to the front inputs (see page 18).
11. FRONT XOVER FREQ.
Use this control to adjust the front crossover frequency from 20Hz to 5kHz (see page 16).
12. FRONT INPUTS
Plug in the front RCA leads from your head unit here (see page 14).
13. L/R OUTPUTS
Left and Right RCA outputs provide summed mono low pass signal to another amplifier.
23456
7
8
9
10 11 12 13

BACK TO CONTENTS
FRONT
L - L + R E M R + R -
REAR
L - L + R + R -
FRONT INPUT L / R
OUTPUT L / R
L R
REAR INPUTS
QBASS
-12dB
FRONT
GAIN
COMBINE
FRONT HP FREQ.
REAR HP FREQ.
REAR
GAIN
REAR LP FREQ. Q SELECT
4/2
REAR HP/LP
1 2
12
ENDPLATE DIAGRAM
4800
1. REAR LP FREQ.
Use this control to adjust the rear low pass crossover frequency from 44Hz to 315Hz
(see page 16).
2. REAR GAIN
Use this control to match the output level of the head unit to the rear channel of
the amplifier (see page 18).
3. FRONT GAIN
Use this control to match the output level of the head unit to the front channel of
the amplifier (see page 18).
4. QBASS 1
Use this switch with the QBASS 2 to program the Q BASS PLUS
™circuit. (see page 15).
5. QBASS 2
Use this switch with the QBASS 1 to program the Q BASS PLUS
™circuit. (see page 15).
6. Q SELECT 4/2
Push this button in for a Q setting of 4 and out for a setting of 2.
7. FORCED AIR EXHAUST VENTS (see page 18 and 19).
8. SPEAKER/REMOTE CONNECTOR
After connecting remote and speaker wires, plug in the PowerLock
connectors here (see pages 7-9).
14
2356 78
9
10 11 12 13 14 15 16 17
9. REAR HP/LP switch
This switch is used to select whether the amplifier will provide a high
pass (switch IN) or mono low pass (switch OUT) signal to the rear speakers. (see page 16).
10. REAR HP FREQ.
Use this to adjust the rear high pass crossover frequency from 20Hz to 5kHz (see page 16).
11. REAR INPUTS
Plug in the rear RCA leads from your head unit here (see page 14).
12. -12dBFor use with high level inputs (4V up to 12V). Push this switch
in to attenuate the input by 12dB (see page 14).
13. COMBINE
Push this switch in to connect the rear channels to the front inputs (see page 18).
14. FRONT HP FREQ.
Use this to adjust the rear high pass crossover frequency from 20Hz to 5kHz (see page 16).
15. FRONT INPUTS
Plug in the front RCA leads from your head unit here (see page 14).
16. OUTPUTS
Left and Right RCA outputs provide high pass or mono low pass signal to another amplifier.
17. FORCED AIR INTAKE VENTS (see page 18 and 19).

BACK TO CONTENTS
13
ENDPLATE DIAGRAM
6600
SUBWOOFER
L - L + R E M R + R -
REAR
L - L + R + R -
REAR INPUTS
L / R
FRONT INPUTS
L / R
FRONT
GAIN REAR
GAIN
-12dB
SUB
GAIN
COMBINE
XOVER FREQ.
QBASS
FRONT REAR
12
FRONT
L - L + R + R -
Q SELECT 4/2
12345
6
7
8
9101112 13 14
1. FRONT GAIN
Use this control to match the output level of the head unit to the front channel of
the amplifier (see page 18).
2. REAR GAIN
Use this control to match the output level of the head unit to the rear channel of
the amplifier (see page 18).
3. SUB GAIN
Use this control to match the output level of the head unit to the sub channel of
the amplifier (see page 18).
4. COOLING VENTS (see page 18).
5. SPEAKER/REMOTE CONNECTOR
After connecting remote and speaker wires, plug in the PowerLock
connectors here with the screws facing up (see pages 7-9).
6. COMBINE
Push this switch in to connect the rear channels to the front inputs (see page 18).
7. Q SELECT 4/2
Push this button in for a Q setting of 4 and out for a setting of 2 (see page 15).
8. QBASS 1
Use this switch with the QBASS 2 to program the Q BASS PLUS
™circuit.(see page 15).
9. QBASS 2
Use this switch with the QBASS 1 to program the Q BASS PLUS
™circuit.(see page 15).
10. FRONT XOVER FREQ.
Use this control to adjust the front crossover frequency from 20Hz to 5kHz (see page 16).
11. REAR XOVER FREQ.
Use this control to adjust the rear crossover frequency from 20Hz to 5kHz (see page 16).
12. -12dBFor use with high level inputs (4V up to 12V). Push this switch
in to attenuate the input by 12dB (see page 14).
13. FRONT INPUTS
Plug in the front RCA leads from your head unit here (see page 14).
14. REAR INPUTS
Plug in the rear RCA leads from your head unit here (see page 14).

BACK TO CONTENTS
There are two sets of RCA INPUTS on the front end of your amplifier.
Plug the RCA cables from your head unit into the appropriate set of
inputs, front and rear. If your head unit doesn't have RCA outputs
don't worry. Simply add a set of RCA plugs (available at your dealer)
to your front or rear set of speaker leads (see drawing below), plug
them into the input jacks, and push in the -12dB switch.
Balanced Differential Inputs
This circuitry reduces noise radiated into your signal cables by up to
40dB.This is equivalent to a noise reduction of approximately one
hundred times what the noise level would be without this circuitry.
It provides all the benefits of a true 'balanced' line without the need
of any special cables (see diagram below).This type of input works
with any conventional RCA cable.
14
INPUTS
WARNING: If you are using a source unit with bridged high powered (or
"floating ground") speaker outputs, a suitable high to low level adapter
must be used. If you are unsure about your head unit see your local
PrecisionPower dealer or call 1-800-62Power.
(+) Positive
(-) Negative
LEFT input
(+) Positive
(-) Negative
RIGHT inpu
t
eject
VOLUME
BASS TREBLE
RIGHT
LEFT
BALANCE TRACK
REVERSE
FOWARD
1234
876
5
PPI MAR KET ING DPT
Trk 1
SOURCE Headunit
music noise
( - = 0 )
noise cancels music
NO noise
(+)
noise ( )
music noise
( + =)
music noise music
and noise
signal and ground
(+)
( )

BACK TO CONTENTS
Q BASS PLUS
™
Settings
1 2 Freq.
IN IN 30Hz
IN OUT 36Hz
OUT IN 44Hz
OUT OUT 60Hz
Q BASS
™
and
Q BASS REMOTE
™
15
CAUTION: QBASS
™
and
QBASS PLU S
™
should only be used in
systems with strong subwoofers. 18dB is a lot of bass boost and
could damage full range speakers.
+18dB
+6dB
0dB
30Hz 36Hz 44Hz 60Hz
Q = 4 Q = 2
+12dB
QBASS PLUS
™
Q BASS
™
For extra BOOM from your system, we've developed the
QBASS
™
bass control circuit.The QBASS control is located
to the left of the speaker outputs, and allows you to add up to
12dB of boost centered at 40Hz by rotating the control clockwise.
QBASS™
QBASS
™
Is a standard feature on the PC4200/PC4400 .
Q BASS PLUS
™
On PC4800 and PC6600 amplifiers, we've taken bass control
to a higher level with QBASS PLUS
™
. The two QBASS switches
(labeled 1 and 2) on the front end of the amplifier allow you
to select one of four frequency centers - 30Hz, 36Hz, 44Hz
and 60Hz. The Q SELECT switch determines the width of
boosted frequencies. A 'Q' of 2 (switch out) will give you a
wide boost while a 'Q' of 4 will boost a narrow range of
frequencies. (See chart below.) On the rear end panel you
will find the QBASS PLUS
™
level control and the plug-in
for an optional QBASS REMOTE
™
level control. Adjust the
level control clockwise for up to 18dB of boost at your
selected frequency and Q.

BACK TO CONTENTS
The front crossover is high pass and can be adjusted from 20Hz to 5kHz by
turningtheFRONTHPFREQ.control.If youneedfull-range,turnthe control
fully counterclockwise to the 20Hz position.The rear crossover can be high
pass or low pass, chosen by the REAR HP/LP switch.The REAR XOVER
FREQ.control determines the rear crossover frequency between 20Hz and
5kHz,20Hzbeingfullycounterclockwise.TheRCAoutputsarealwaysmono
low pass at 90Hz to send a subwoofer signal to another amplifier.
The front crossover is high pass and can be adjusted from 20Hz to 5kHz by
turningtheFRONTHPFREQ.control.If youneedfull-range,turnthe control
fully counterclockwise to the 20Hz position. The rear crossover actually
consists of two crossovers, one high pass and one mono low pass. The
high pass section is a 12dB/octave Linkwitz-Riley type that is adjustable
from 20Hz to 5kHz using the REAR HP FREQ. control. For full range
operation, turn the control fully counterclockwise to the 20Hz position.The
low pass section is a 24dB/octave Linkwitz-Riley type that you can adjust
from 44Hz to 315Hz with the REAR LP FREQ. control. High pass or low
pass to the rear channel is determined by the REAR HP/LP switch, 'OUT'
being low pass and 'IN' being high pass. When you select high pass, the
RCA outputs will be low pass and vice versa.
Thefront and rearcrossovers areboth high pass,and can beadjusted from
20Hzto 5kHz usingthe XOVER FREQ.FRONTand REAR controls.For full
rangeoperation,turnthe control fullycounterclockwiseto the 20Hzposition.
Thesubwoofercrossoverisa 24dB/octaveLinkwitz-Rileytypefixedat90Hz.
See system diagrams starting on page 21 for examples!
CROSSOVER Operation
16
Your new POWERCLASS
™
amplifier has crossover circuits built-in to provide
exceptional system flexibility without the added expense and installation of an
outboard crossover. See the frequency detent charts on page 17 to set your
amplifier's crossover.
PC4200 / PC4400
PC4800
PC6600

BACK TO CONTENTS
FREQUENCY DETENT CHARTS
PC4200 / PC4400 / PC4800 / PC6600
The crossover frequency range of your new POWERCLASS
™amplifier goes from
20Hz-5kHz,and the controls are detentedforaccuratetuning. Each "click"counted
fromthe fullcounterclockwiseposition correspondsto a specific frequency.Referto
this chart for set-up instructions.
1 20 Hz
2 21 Hz
3 21 Hz
4 21.5 Hz
5 22 Hz
6 23 Hz
7 24.5 Hz
8 26 Hz
9 27.5 Hz
10 30 Hz
11 32 Hz
12 35 Hz
13 39 Hz
14 43 Hz
15 49 Hz
16 56 Hz
17 64 Hz
18 73 Hz
19 80 Hz
20 88 Hz
21 100 Hz
22 114 Hz
23 134 Hz
24 160 Hz
25 196 Hz
26 260 Hz
27 320 Hz
28 368 Hz
29 432 Hz
30 496 Hz
31 608 Hz
32 752 Hz
33 864 Hz
34 1008 Hz
35 1200 Hz
36 1488 Hz
37 1952 Hz
38 2816 Hz
39 4512 Hz
40 4944 Hz
41 5000 Hz
DETENT
1 44 Hz
2 44 Hz
3 44 Hz
4 45 Hz
5 46 Hz
6 48 Hz
7 51 Hz
8 54 Hz
9 58 Hz
10 62 Hz
11 67 Hz
12 72 Hz
13 78 Hz
14 85 Hz
15 94 Hz
16 104 Hz
17 115 Hz
18 124 Hz
19 132 Hz
20 141 Hz
21 150 Hz
22 162 Hz
23 175 Hz
24 189 Hz
25 207 Hz
26 227 Hz
27 240 Hz
28 249 Hz
29 258 Hz
30 268 Hz
31 280 Hz
32 287 Hz
33 290 Hz
34 295 Hz
35 298 Hz
36 303 Hz
37 307 Hz
38 311 Hz
39 315 Hz
40 315 Hz
41 315 Hz
DETENT
17
PC4200/PC4400 - Front HP & Rear Xover Freq.
PC4800 - Front and Rear HP Freq.
PC6600 - Front and Rear Xover Freq.

BACK TO CONTENTS
Input Combine
Your multi channel POWERCLASS™ amplifier can use both front
and rear outputs from your head unit to maintain the ability to fade
front to rear, or you can run a single set of RCAs to the front inputs
and push in the COMBINE switch on the amplifier end plate to route
the front signal to the rear channels as well.
Adjusting The Amplifier Input Gain
1. Adjust all amplifier input gain controls to just above minimum
sensitivity (fully counterclockwise).
2. Using the cleanest source (CD), with music playing turn up
the head unit until you can hear distortion. Now turn it down a
bit until you cannot hear the distortion.
3. Increase the Amplifier gain (clockwise) until the onset of
audible distortion.Then decrease the gain to the point just
before the distortion starts.This setting minimizes background
noise and prevents overload.
4. Repeat step 3 for any remaining amplifiers in the system.
Heatsink Cooling
The unique heatsink on your POWERCLASS™ amplifier has
been designed with fins on the inside of the aluminum mass.
This allows for the transfer of heat from the circuitry to the
heatsink fins and out through the vents in the endplates. Be
sure you have ample space around the amplifier for cooling,
at least 2" on all sides.
INPUT COMBINE and GAIN
18