Rockford Fosgate PUNCH 4020 DSM User manual


PUNCH 4020 DSM
4-CHANNEL AMPLIFIER
®®
INSTALLATION & OPERATION

Dear Customer,
Congratulations on your purchase of the world's finest brand of car audio
amplifiers. At Rockford Fosgate we are committed to musical reproduction at its
best, and we are pleased you chose our product. Through years of engineering
expertise, hand craftsmanship and critical testing procedures, we have created a
wide range of products that reproduce music with all the clarity and richness you
deserve.
For maximum performance we recommend you have your new Rockford Fosgate
product installed by an Authorized Rockford Fosgate Dealer, as we provide
specializedtrainingthroughRockfordTechnicalTrainingInstitute(RTTI). Please
read your warranty and retain your receipt and original carton for possible future
use.
ToaddthefinishingtouchtoyournewRockfordFosgateimageorderyourRockford
accessories, which include everything from T-shirts and jackets to hats and
sunglasses.
To get a free brochure on Rockford Fosgate products and Rockford accessories,
please call 602-967-3565 or FAX [phone]. In Canada, call Korbon
Tradingat905-567-1929.ForInternationalorders,FAX[phone]
or call +001-1-602-967-3565.
The serial number can be found on the outside of the box. Please record it
in the space provided below as your permanent record. This will serve as
verification of your factory warranty and may become useful in recovering
your amplifier if it is ever stolen.
Serial Number: ____________________
Model Number:____________________
If, after reading your manual, you still have questions regarding this
product, we recommend that you see your Rockford Fosgate dealer. If you
needfurtherassistance,youcancallusdirectat1-800-795-2385.Besureto
have your serial number, model number and date of purchase available
when you call.
PRACTICE SAFE SOUND™
CONTINUOUS EXPOSURE TO SOUND PRESSURE LEVELS
OVER100dBMAYCAUSEPERMANENTHEARINGLOSS.HIGH
POWEREDAUTOSOUNDSYSTEMSMAYPRODUCESOUND
PRESSURE LEVELS WELL OVER 130dB. USE COMMON SENSE
AND PRACTICE SAFE SOUND.

GETTING STARTED
TABLE OF CONTENTS
Introduction ...................................................................................... 1
Punch 4020 Amplifier Accessory Pack .............................................. 1
Rockford Fosgate Accessories............................................................ 2
Technical Design Features ................................................................ 3
Punch 4020 Design Features............................................................. 6
Installation Considerations ................................................................ 8
Mounting Location............................................................................ 9
Battery and Charging....................................................................... 10
Wiring the System ........................................................................... 10
Using the XCard.............................................................................. 12
Sample Wiring Diagrams ................................................................ 14
Troubleshooting .............................................................................. 18
Dynamic Power Measurements....................................................... 21
Specifications.................................................................................. 23
Warranty Information...................................................................... 24
Welcome to Rockford Fosgate! This manual is designed to provide
information on the Punch 4020 amplifier for owner, salesperson
and installer. To accomplish this, the manual is divided into five
main sections: Introduction, Installation, Troubleshooting, Specifi-
cationsandWarrantyInformation.Forthoseofyouwhowantquick
information on how to install this product, please turn to the Basic
System Diagrams in the Installation section of this manual. Other
information can be located by using the Table of Contents. We, at
Rockford Fosgate, have worked very hard to make sure all the
information in this manual is current. But, as we are constantly
findingnewwaystoimproveourproduct,thisinformationissubject
to change without notice.

– 1 –
INTRODUCTION
The Punch 4020 is a 4-channel amplifier which offers 20 Watts
perchannelwhendriveninto4Ohms.Theamplifierutilizesa2/
4 input selector switch and XCard crossovers.
When building a 4-channel amplifier, a major design challenge
is to maintain sound quality in a limited space. For the Punch
4020, Rockford Fosgate Engineers designed the Trans• Ana to-
pologywhichisafast,shortloopcircuitallowingtheoutputstage
tobe driven witha low voltagedrive signal.Withthe additionof
a 2/4 input selector switch and XCard crossovers, the 4020 can
beconfiguredinmanypopularsystemdesignswithouttheadded
cost of external processors. The result is an excellent sounding
amplifier in a physically compact area.
The Punch 4020 satisfies the need for a powerful 4-channel
amplifier at a competitive price.
We strongly recommend you have your Authorized Rockford
Fosgate Dealer install the new Punch 4020 amplifier. If you do
choose to install it yourself, please be sure to read the entire
manual before beginning.
PUNCH 4020 AMPLIFIER
ACCESSORY PACK
The accessory pack shipped with the Punch 4020 amplifiers
include the mounting hardware necessary to secure it to the
vehicle as well as attaching the end caps.
Installation & Operation Manual
Punch Verification Certificate
(10)Hex Head screws for speaker and power connectors
(4) Mounting screws for end caps
(4) Mounting screws for amplifier
(1) Allen wrench 7/64"
(1) Allen wrench 13/32"

– 2 –
ROCKFORD FOSGATE ACCESSORIES
Thefollowingaccessorieswere designed to enhance the perfor-
mance of the Punch 4020 amplifier.
Energy Storage Capacitor (PCH-C1)
The Punch 1 farad capacitor is used to provide extra current
neededbyamplifierstoreproducemusicaltransients.ThePunch
Cap also has the natural ability to filter DC ripple caused by the
alternator which can result in noise in the system. The PCH-C1
will maximize both the sound quality and performance that
Rockford Fosgate amplifiers can deliver.
Punch Link (FG-LINK)
The Punch Link is a specially cast heatsink interconnect which
allows you to join any of our current Punch or Punch Power
amplifiers together. While providing additional cooling through
thecouplingprocess, the PunchLink adds thefinishingtouch by
giving you the look of one awesome amplifier.
XCard
Additional crossover card frequencies are available for special-
ized requirements. You can get the following XCards from your
Authorized Rockford Fosgate Dealer.
XM50 = 50Hz XM275 = 275Hz
XM70 = 70Hz XM400 = 400Hz
XM100 = 100Hz XM4.5k = 4,500Hz
XM150 = 150Hz XM6.5k = 6,500Hz
XM200 = 200Hz XM00 = Blank card for
custom crossover

– 3 –
TECHNICAL DESIGN FEATURES
◆trans• ana
Thetrans• ana (TRANSconductanceAdvancedNon-multiplying
Amplifier)isanovelcircuitthatutilizesashort-loopcomplemen-
tary topology and advanced Real Time Protection circuitry.
THERESULT:Anamplifierdesignwiththebenefitsoftubeandbi-
polar transistor amplifier design without the limitations of either.
◆MOSFET Devices
Rockford Fosgate is one of the few manufacturers in any of the
soundcommunitiestoutilizeMOSFETdevicesinboththe power
supply and the output stages . MOSFET (Metal Oxide Semicon-
ductor Field Effect Transistor) devices offer several important
inherent advantages over the 30 year old technology of bi-polar
design. These advantages include: thermal stability, switching
speed, ultra low output impedance and wider bandwidth linear-
ity. In addition, MOSFET and vacuum tubes share many impor-
tant operating characteristics. However, the MOSFET device is
much faster, wider in bandwidth, measurably lower in distortion
and far more linear than vacuum tubes.
THE RESULT: Operational characteristics of vacuum tubes
without the performance limitations of tube design.
◆DSM (Discrete Surface Mount) Technology
The DSM (Discrete Surface Mount) manufacturing process com-
binestheadvantagesofbothdiscretecomponentsandintegrated
circuitry.RockfordFosgateis theonlyAmericanamplifiermanu-
facturerto haveinvested millionsinto thisprocess. DSMcompo-
nents differ from conventional discrete components in three
different ways. They are more compact and more rugged, and
they take much better advantage of the PC board to allow them
to get rid of any heat they generate. Using them wherever
appropriate allows the advantages associated with discrete thru-
hole circuitry to be retained while also providing room for both
highly advanced processing features and generous PC board
copperpathswhereneeded.Theirshortlead-outstructuresallow
maximum audio performance and highest signal-to-noise ratios

– 4 –
to be obtained in amplifiers of desirable package size without
resorting to “amplifier-on-a-chip”shortcuts. These advantages
are shown below in Figure 1.
THE RESULT: Less connections, improved reliability, shorter
signal paths, superior signal-to-noise ratio and awesome sonic
performance.
Figure 1
Thru-Hole Surface Mount
Component
Solder Solder
◆TOPAZ (Tracking Operation Pre-Amplifier Zone)
The TOPAZ (Tracking Operation Pre-Amplifier Zone) circuitry
solves ground loop noise problems common to automotive
amplifierdesign.Thisinnovativenewdevelopmentallowsvastly
improved isolation of the input signal grounds from the power
supplygroundoftheamplifier.Thisisaccomplishedbyallowing
the source unit to control the potential “environment”of the
entire input structure or “zone”of the amplifier. This process
improves the noise rejection of the amplifier by 30-40dB –an
astounding 30-100 times better than amplifiers without TOPAZ.
THE RESULT: Elimination of troublesome ground loop noise
between source and amplifier.

– 5 –
◆XCard (Internal Crossover)
The Punch 4020 amplifier utilizes internal active crossovers. These
crossovers have many performance advantages such as using dis-
crete components for exact frequency adjustments which are far
superior to potentiometers. Additionally, the XCard can be config-
ured for high-pass, low-pass and full range operation. With slight
modification,many crossoverfrequencies andslopeconfigurations
can be achieved.
THE RESULT: Increased system design flexibility with a precise
electronic crossover without the limitations of conventional poten-
tiometer designs.
◆RTP (Real Time Protection)
NOMAD (NOn-Multiplying Advanced Decision)
The Punch 4020 amplifier uses an analog computer process to
absolutely maximize safe output power under all operating condi-
tions. Rockford Fosgate pioneered and developed RTP (Real Time
Protection), a crucial element in the performance edge of our
amplifiers. The innovative NOMAD (NOn-Multiplying Advanced
Decision) system is the most sophisticated version of this technique
ever used, bringing previously unavailable levels of accuracy,
stability, temperature immunity and reliability to this critical pro-
cess.NOMADmakesadvanceddecisionsbasedondevicevoltages
to precisely control the awesome levels of current available in the
output MOSFETs to safe values –but only when absolutely needed.
THE RESULT: Extremely fast protection system that always protects
the amplifier and never degrades the sound.

PUNCH 4020 DESIGN FEATURES
1. Cast Aluminum Heatsink – The cast aluminum heatsink of the
Punch amplifier dissipates heat generated by the amplifier's
circuitry. The inherent advantage of casting provides a 30%
improvement of cooling over conventional extrusion heatsink
designs.
2. End Caps – Interchangeable end caps conceal the wiring and
input cables, giving the amplifier a clean “stealth” look.
– 6 –
3. SpeakerTerminals–Theheavyduty,gold-platedterminalblock
connectors (+ and –) will accept wire sizes from 8 AWG to 18
AWG. These gold-plated connectors are immune to corrosion
that can cause signal deterioration.
4. Power Terminals – The power and ground connectors on the
Punch amplifier are gold-plated and will accommodate up to 8
AWG wire maximizing the input current capability of the
amplifier.
5. REM Terminal – This spade terminal is used for the AP (auto
power) or remote turn on of the Punch amplifier.
Front Gain
Front Rear
R
L
Rear Gain
Rear Speakers
386683
– L +
(Bridged Mono)
R
L
–R +
Front Speakers
+ L –
(Bridged Mono)
+ R –
REM B+ GND
4
510
POWER

– 7 –
6. RCA Input Jacks – The industry standard RCA jack provides an
easy connection for signal level input. They are gold-plated to
resist the signal degradation caused by corrosion.
7. Signal Input Switch– Thisswitchallowsselectionof2channel
or 4 channel source unit feed.
8. Input Sensitivity Controls – The input level controls are preset
for 500mV which will match the output of most source units.
Theycanbeadjustedtomatchinputlevelsrangingfrom150mV
to 3V.
9. Internal Crossovers – These built-in crossover cards are
configurable for a multitude of operating frequencies. The
orientation of the card in its socket determines the function of
high-pass, low-pass, or full range operation.
10. LED Power Indicator – The LED illuminates when the unit is
turned on.
Low Pass Full RangeHigh Pass
FULL
↕
HP
➝
➝
LP
HP
➝
➝
LP
®
DSM
XCard 2
ROCKFORD CORPORATION
MADE IN THE USA
®
Rear
XCard Front
XCard
®
20 Watts x 4 into 4Ωat 0.05% THD
30 Watts x 4 into 2Ωat 0.1% THD
AMPLIFIER
XCard 1
79

INSTALLATION CONSIDERATIONS
– 8 –
This section focuses on some of the vehicle considerations for
installing your new Punch amplifier. Checking your battery and
presentsoundsystem,aswellaspre-planningyoursystemlayoutand
best wiring routes will save installation time. When deciding how to
lay out your new system, be sure that each component will be easily
accessible for making adjustments.
Beforebeginninganyinstallation,besuretofollowthesesimplerules:
1. Be sure to carefully read and understand the instructions before
attempting to install the amplifier.
2. For safety, disconnect the negative lead from the battery prior to
beginning the installation.
3. For easier assembly, we suggest you run all wires prior to
mounting your amplifier in place.
4. Route all of the RCA cables close together and away from any
high current wires.
5. Use high quality connectors for a reliable installation and to
minimize signal or power loss.
6. Thinkbeforeyoudrill! Becarefulnottocutordrillintogastanks,
fuel lines, brake or hydraulic lines, vacuum lines or electrical
wiring when working on any vehicle.
7. Never run wires underneath the vehicle. Running the wires
inside the vehicle provides the best protection.
8. Avoid running wiresoveror through sharpedges. Use rubberor
plastic grommets to protect any wires routed through metal,
especially the firewall.
9. ALWAYS protect the battery and electrical system from damage
with proper fusing. Install a fuseholder and fuse on the +12V
power wire within 18” (45.7 cm) of the battery terminal.
10. When grounding to the chassis of the vehicle, scrape all paint
from the metal to ensure a good, clean ground connection.
Groundingconnectionsshouldbeasshortaspossibleandalways
beconnectedtometalthatisweldedtothemainbody,orchassis,
of the vehicle.
The following is a list of tools you will need for installing the Punch
amplifier:
Allen wrenches 7/64" & 3/32" (included) Voltmeter
Wire strippers Battery post wrench
Electric hand drill w/assorted bits Wire cutters
Wire crimpers Assorted connectors

MOUNTING LOCATION
Themountinglocationandpositionofyouramplifierwillhaveagreat
effect on its ability to dissipate the heat generated under normal
operation. The design of our cast aluminum heatsink serves to easily
dissipate the heat generated over a wide range of operating condi-
tions.However,tomaximizetheperformanceofyouramplifier,care
should be taken to ensure adequate ventilation.
Trunk Mounting
Mounting the amplifier vertically on a surface with the fin grooves
running up and down will provide the best cooling of the amplifier.
Mountingtheamplifieronthefloorofthetrunkwillworkbutprovides
less cooling capability than vertical mounting.
Mountingtheamplifierupsidedowntothereardeckofthetrunkwill
not provide proper cooling and will severely affect the performance
of the amplifier and is strongly not recommended.
Passenger Compartment Mounting
Mounting the amplifier in the passenger compartment will work as
longasyouprovideasufficientamountofairfortheamplifiertocool
itself. If you are going to mount the amplifier under the seat of the
vehicle, you must have at least 1" (2.54cm) of air gap around the
amplifier's heatsink.
Mounting the amplifier with less than 1" (2.54cm) of air gap around
the amplifier's heatsink in the passenger compartment will not
providepropercoolingandwillseverelyaffecttheperformanceofthe
amplifier and is strongly not recommended.
Engine Compartment Mounting
Rockford Fosgate amplifiers should never be mounted in the engine
compartment.Not only willthis voidyourwarranty butcould create
an embarrassing situation caused by the ridicule from your friends.
– 9 –

Amplifiers will put an increased load on the vehicle's battery and
charging system. We recommend checking your alternator and
battery condition to ensure that the electrical system has enough
capacity to handle the increased load of your stereo system. Stock
electrical systems which are in good condition should be able to
handle the extra load of any Rockford amplifier without problems,
although battery and alternator life can be reduced slightly. To
maximize the performance of your Rockford Fosgate amplifier, we
suggest the use of a heavy duty battery, high output alternator and a
stiffening capacitor like the Rockford Fosgate PCH-C1.
– 10 –
BATTERY AND CHARGING
WIRING THE SYSTEM
CAUTION: Avoid running power wires near the low level input
cables,antenna,power leads,sensitiveequipmentor harnesses.The
powerwirescarrysubstantialcurrentandcouldinducenoiseintothe
audio system.
1. Plan the wire routing. Take care when running signal level RCA
cablestokeepthemclosetogetherbutisolatedfromtheamplifier's
power cables and any high power auto accessories, especially
electric motors. This is done to prevent coupling the noise from
radiated electrical fields into the audio signal. When feeding the
wires through the firewall or any metal barrier, protect them with
plastic or rubber grommets to prevent short circuits. Leave the
wires long at this point to adjust for a precise fit at a later time.
2. Prepare the Power cable for attachment to the amplifier by
stripping 5/8" of insulation from the end of the wire. The use of 8
gauge power cable can interfere with the installation of the end
caps. Proper wire dress can prevent this from occurring. To
prevent the wire from fraying, strip the insulation at a 45°angle.
Insertthebared wireintotheB+terminal withthelongsideofthe
insulationonthetop.Bendthecabledownata90°angle.Tighten
the set screw to secure the cable in place.
NOTE: TheB+cableMUSTbefused18"orlessfromthevehicle's
battery. Install the fuseholder under the hood and prepare the
cable ends as stated above. Connections should be water tight.

– 11 –
3. Preparealengthofcabletobeusedforthegroundconnection.
Strip 5/8" of insulation from the end of the cable as described
above and connect to the appropriate terminal of the ampli-
fier.Preparethechassisgroundbyscrapinganypaintfromthe
metal surface and thoroughly clean the area of all dirt and
grease. Strip the other end of the wire and attach a ring
connector. Fasten the cable to the chassis using a screw.
4. Prepare the REM turn-on wire for connection to the amplifier
bystripping5/8"ofinsulationfromthewireendandcrimping
an insulated spade connector in place. Slide the connector
overtheREMterminalontheamplifier.Connecttheotherend
of the REM wire to a switched 12 volt positive source. The
switched signal is usually taken from the source unit's auto
antennaortheaccessorylead.Ifthesourceunitdoesnothave
these outputs available, the recommended solution is to wire
a mechanical switch in line with a 12 volt source to activate
the amplifier.
5. ConnectthesourcesignaltotheamplifierbypluggingtheRCA
cables into the input jack(s) at the amplifier.
6. Connect the speakers. Strip the speaker wires 5/8" and insert
intotheappropriateterminalontheamplifier.Insertthebared
wire into the speaker terminal and tighten the set screw to
secureintoplace. Besuretomaintainproperspeakerpolarity.
DONOT chassis groundany of thespeaker leads asunstable
operation may result.
7. Performafinalcheckofthecompletedsystemwiringtoensure
thatallconnectionsareaccurate.Checkallpowerandground
connections for frayed wires and loose connections which
could cause problems from road vibrations.
8. After the final inspection is complete, install the power fuse
and enjoy listening. During the initial listening period, you
may need to “fine tune” any phasing and level settings within
your particular vehicle. To aid in this procedure, play a track
with high musical content and cruise around your neighbor-
hood. After fully evaluating the transient response of your
system and making any final adjustments, all your neighbors
within a 1 mile radius will assume that you have just success-
fully completed another upgrade to your audio system for
which they will probably spill thumbtacks on your driveway.

– 12 –
USING THE XCARD
The crossover functions are controlled through the use of an
XCard and can be set for high-pass, low-pass or full range
operation. These cards are shipped in the most common fre-
quency.Eachcrossovercardhastwofaces:onefaceoperatesFull
Range, the other has arrows to indicate the edge for selecting HP
(high-pass) or LP (low-pass) operation. Orient the card with the
desiredoperatingedge,indicatedbythearrow,towardthesocket
terminalsinsidetheamplifier.Firmly,butcarefully,plugthecard
into the socket.
Low Pass Full RangeHigh Pass
FULL
↕
HP
➝
➝
LP
HP
➝
➝
LP
Thecrossoverpointcanbealteredbychangingtheresistorvalue.
Usethefollowingformulatoselecttheappropriateresistorvalue
to be placed on the XCard.
3386
fo= R (in kΩ) for .047µf cap
= R (in kΩ) for .022µf cap
7234
fo
Where: R = Ω
fo= desired crossover frequency
c = capacitor in farads
ex: .047 x 10-6 for .047mf cap
Crossover Card
High Pass
Low Pass
Full Range
R1 R2 R1 R2
FULL
The actual formula is:
R = 1
2πfoc

4020 POWER CONNECTIONS
– 13 –
4
510
POWER
Connect to remote
turn-on lead of
source unit. Connect to chassis
ground of vehicle*
Connect to B+ of battery
with a 30 amp fuse.
Less than 18"
B+ GND
REM
*Keep grounds as short as possible.

SAMPLE WIRING DIAGRAMS
– 14 –
4-CHANNEL STEREO
+ –
2ΩMinimum
High Frequency
+ –
2ΩMinimum
Low Frequency
+ –
Front Gain
Front Rear
Rear Gain
(Bridged Mono)
+ L –+ R –
(Bridged Mono)
Front Speakers Rear Speakers
+ –
–L + –R +
R
L
R
L
Front Rear
• Signal input switch to 4 channel input.
•Gain for Front and Rear operate independently.
•Front is operating in stereo.
•Rear is operating in stereo.
• Experiment with subwoofer polarity to determine
which sounds best in your system.
*Note: XCard can be inserted in HP,
LP, or Full Range.
XCard 1 XCard 2
HP
LP
Rear XCard* Front XCard*

– 15 –
4-CHANNEL – STEREO FRONT
MONO REAR
4ΩMinimum
Low Frequency
+ –
2ΩMinimum
High Frequency
+ –
Front Gain
Front Rear
Rear Gain
(Bridged Mono)
+ L –+ R –
(Bridged Mono)
Front Speakers Rear Speakers
+ –
–L + –R +
R
L
R
L
Front Rear
*Note: XCard can be inserted in HP,
LP, or Full Range.
XCard 1 XCard 2
HP
LP
Rear XCard* Front XCard*
• Signal input switch to 4 channel input.
•Gain for Front and Rear operate independently.
•Front is operating in stereo.
•Rear is operating in stereo.
• Fader on source unit controls level of subwoofer.
• Experiment with subwoofer polarity to determine
which sounds best in your system.

– 16 –
Rear XCard* Front XCard*
• Signal input switch to 2 channel input.
•Gain for Front and Rear operate independently.
•Front is operating in mono.
•Rear is operating in mono.
XCard 1 XCard 2
LP
LP
*Note: XCard can be inserted in HP,
LP, or Full Range.
4ΩMinimum
Low Frequency
–+
Front Gain
Front Rear
Rear Gain
(Bridged Mono)(Bridged Mono)
Front Speakers Rear Speakers
–L + –R +
R
L
R
L
Front Rear
4ΩMinimum
Low Frequency
+ –
+ L –+ R –
2-CHANNEL – MONO

– 17 –
4-CHANNEL – STEREO/MONO FRONT
STEREO REAR
+ –
4ΩMinimum
Low Frequency
+ –
2ΩMinimum
High Frequency
+ –
2ΩMinimum
High Frequency
–+
Front Gain
Front Rear
Rear Gain
(Bridged Mono)
+ L –+ R –
(Bridged Mono)
Front Speakers Rear Speakers
+ –
–L + –R +
R
L
R
L
Front Rear
2ΩMinimum
High Frequency
• Signal input switch to 4 channel input.
•Gain for Front and Rear operate independently.
•Front is operating in stereo/MONO.
•Rear is operating in stereo.
• Fader on source unit controls level of rear.
Note: XCard can be inserted in HP,
LP, or Full Range.
XCard 1 XCard 2
Full Range
HP
Rear XCard* Front XCard*