Rockford Fosgate 125.2, 225.2, 55.2, 75.2 User Manual

h

trans•

ana

® ®

trans•

trans•

trans•

ana

ana

ana

car audio

for

fanatics

2-Channel Amplifiers
Operation & Installation

®

punc

Dear Customer,
Congratulations on your purchase of the world's finest brand of car audio amplifiers.

At Rockford Fosgate we are fanatics about 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 specialized
training through Rockford Technical Training Institute (RTTI). Please read your
warranty and retain your receipt and original carton for possible future use.

Great product and competent installations are only a piece of the puzzle when it comes
to your system. Make sure that your installer is using 100% authentic installation
accessories from Connecting Punch in your installation. Connecting Punch has
everything from RCA cables and speaker wire to Power line and battery connectors.
Insist on it! After all, your new system deserves nothing but the best.

To add the finishing touch to your new Rockford Fosgate image order your Rockford
wearables, which include everything from T-shirts and jackets to hats and sunglasses.

To get a free brochure on Rockford Fosgate products and Rockford accessories, in the
U.S. call 602-967-3565 or FAX [phone]. For all other countries, call +001-602­967-3565 or FAX [phone].

PRACTICE SAFE SOUND™

CONTINUOUS EXPOSURE TO SOUND PRESSURE LEVELS OVER 100d B

CAUSE PERMANENT HEARING LOSS. HIGH POWERED AUTOSOUND

MAY
SYSTEMS

MAY PRODUCE SOUND PRESSURE LEVELS WELL OVER

130dB. USE COMMON SENSE AND PRACTICE SAFE SOUND.

If, after reading your manual, you still have questions regarding this product,
we recommend that you see your Rockford Fosgate dealer. If you need further
assistance, you can call us direct at 1-800-669-9899. Be sure to have your serial
number, model number and date of purchase available when you call.

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:________________________________

T

ABLE OF

C

ONTENTS

Introduction................................................................................................1

Punch Amplifier Accessory Pack ................................................................... 1

Technical Design Features............................................................................2

Design Features .......................................................................................... 5

Installation Considerations ........................................................................... 7

Mounting Location ...................................................................................... 8

Battery and Charging .................................................................................. 9

Wiring the System....................................................................................... 9

Using Passive Crossovers........................................................................... 12

Table of Component Values........................................................................13

Using the XCard........................................................................................ 14

Resistor Chart ........................................................................................... 15

Installation ............................................................................................... 16

System Diagrams......................................................................................20

Rockford Fosgate Accessories ..................................................................... 24

Troubleshooting........................................................................................ 26

Dynamic Power Measurements...................................................................29

Specifications ........................................................................................... 31

Warranty Information ................................................................................ 33

International Information............................................................................ 34

GETTING STARTED

Welcome to Rockford Fosgate! This manual is designed to provide information
for the owner, salesperson and installer. For those of you who want quick
information on how to install this product, please turn to the

Section

of this manual or refer to the icons listed below. 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 finding new ways to improve our product, this information
is subject to change without notice.

I

a

O
p

d

e

v

r

a

a

n

t

c

i

e

o

d

n

Sections marked

ADVANCED OPERATION

include in-depth

technical information

® ®

N
S
T
A
L
L
A
T
I
O
N

Sections marked

INSTALLATION

include “slam dunk”

wiring connections

include recommendations for

curing installation problems

Installation

TROUBLE-

S
H
O
O
T
I
N
G

Sections marked

TROUBLESHOOTING

I

NTRODUCTION

Rockford engineers designed the Punch 55.2, 75.2, 125.2 and 225.2
amplifiers to withstand the rugged automotive environment while delivering
superior sound quality in a flexible, reliable, and efficient package. TRANS•ANA
is a low voltage circuit in the preamp stage of all Punch .2 amplifiers that
lets the music sound crystal clear and very real, even when played at high
volume levels. This is matched with TOPAZ, a unique grounding circuit used
to eliminate noise problems associated with car audio systems and their
installation. Flexibility is accomplished with the use of a built-in XCard.
Reliability is all but guaranteed with the use of a protection circuit called
NOMAD, while MOSFET and DSM (Discrete Surface Mount) technology
improve amplifier efficiency. The result of these components give the Punch
amplifier awesome sound quality in a “Bullet Proof” package. An explana­tion of these technologies, most of which are exclusively designed and
patented by Rockford, are described in the Technical Design Features.

P

UNCH

A

MPLIFIER

The accessory pack shipped with the Punch 2-channel amplifiers includes
the mounting hardware necessary to secure the amp to the vehicle and to
attach the end caps to the amplifier.

A

CCESSORY PACK

Installation & Operation Manual
Punch Verification Certificate
(4) Amplifier mounting screws (#8 x 3/4" Phillips)
(6) Speaker & power connector screws (3/32" Allen)
(4) End cap mounting screws (9/64" Allen)
(1) Allen Wrench 9/64"
(1) Allen Wrench 3/32"
(1) ATC Inline Fuseholder (Punch 55.2, 75.2, 125.2)
(1) AGU Inline Fuseholder (Punch 225.2)
(1) ATC 20 Amp Fuse (Punch 55.2)
(1) ATC 30 Amp Fuse (Punch 75.2)
(1) ATC 40 Amp Fuse (Punch 125.2)
(1) AGU 50 Amp Fuse (Punch 225.2)

– 1 –

T

ECHNICAL

◆ TRANS•ANA

(TRANSconductance Active Nodal Amplifier)

The

TRANS•ANA

that allows the audio signal to pass through the amplifier at low voltage. The
signal is directly level-shifted to the fixed high voltage rails via a pair of driver
transistors. Signal linearity is assured by an active node formed by the drive
transistors at ultrasonic frequencies. This allows amplifier performance
similar to trans•
advantages of a non-floating power supply.

THE RESULT: An extended frequency bandwidth accurately supplied to the
output stages of the amplifier.

◆ MEHSA (Maximum Efficiency Heat Sink Application)

The

MEHSA

process that yields up to 5 times better heat transfer than traditional FET
mounting techniques using the exact same components. A multi-layer
insulated metal substrate operating with minimal thermal resistance spreads
heat both downward & outward to quickly dissipate heat from each device
across the heat sink. This process combined with our DSM technology and
MOSFET devices allow us to squeeze more watts per cubic inch from every
output device as well as provide consistent thermal stability.

D

ESIGN FEATURES

(TRANSconductance Active Nodal Amplifier) is a circuit

nova

which is highly stable and linear while utilizing the

(Maximum Efficiency Heat-Sink Application) is a proprietary

THE RESULT: Optimized power output, enhanced thermal stability, and
maximum component reliability.

◆ TOPAZ (Tracking Operation Pre-Amplifier Zone)

The

TOPAZ

(Tracking Operation Pre-Amplifier Zone) circuitry solves ground
loop noise problems common to automotive amplifier design. This innovative
new development allows vastly improved isolation of the input signal grounds
from the power supply ground of the amplifier. This is accomplished by
allowing 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.

– 2 –

◆ DSM (Discrete Surface Mount) Technology

The

DSM

(Discrete Surface Mount) manufacturing process combines the
advantages of both discrete components and integrated circuitry. Rockford
Fosgate is the only American amplifier manufacturer to have invested millions
into this process. DSM components differ from conventional discrete compo­nents in different ways. They are more compact, more rugged, and they
efficiently dissipate generated heat. Using them wherever appropriate allows
the advantages associated with discrete circuitry to be retained while also
providing room for both highly advanced processing features and generous
PC board copper paths where needed. Their short lead-out structures allow
maximum audio performance and highest signal-to-noise ratios 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: Fewer connections, improved reliability, shorter signal paths,
superior signal-to-noise ratio and awesome sonic performance.

Figure 1

PC

Board

Thru-Hole Surface Mount

Solder

Component

Solder

PC

Board

◆ XCard (Internal Crossover)

The Punch amplifiers utilize internal active crossovers. These crossovers have
many performance advantages such as using discrete components for exact
frequency adjustments which are far superior to potentiometers. Additionally,
the

XCard

can be configured for high-pass, low-pass and full range
operation. With slight modifications, many crossover frequencies and slope
configurations can be achieved.

THE RESULT: Increased system design flexibility with a precise electronic
crossover without the limitations of conventional potentiometer designs.

– 3 –

◆ MOSFET Devices

Rockford Fosgate is one of the few manufacturers in the sound community
to utilize MOSFET devices in both the

MOSFET

several important inherent advantages over the 30 year old technology of bi­polar design. These advantages include: thermal stability, switching speed,
ultra low output impedance and wider bandwidth linearity. In addition,
MOSFETs operate very similarly to vacuum tubes in that they are more linear
than bi-polar transistors. However, MOSFETs can deliver the midrange clarity
without the limitations of transient response and high frequency phase
shifting normally associated with tube operation.

THE RESULT: Operational characteristics similar to vacuum tubes without
the performance limitations of tube design.

(Metal Oxide Semiconductor Field Effect Transistor) devices offer

power supply

and the

output stages

◆ NOMAD (NOn-Multiplying Advanced Decision)

.

The Punch amplifiers use an
output power under all operating conditions. The innovative
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 process. NOMAD
makes advanced decisions based on device voltages 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.

analog computer process

to maximize safe

NOMAD

(NOn-

◆ Punch EQ

The Punch EQ helps correct for acoustical deficiencies in the listening
environment. Two unique potentiometers that control bass and treble
compensate for the response errors present in most car environments. Unlike
conventional tone controls, Punch EQ corrects the specific problems of poor
low bass response and high frequency rolloff.

THE RESULT: Full range sound without excessive boost in areas where it is
not needed.

– 4 –

D

ESIGN 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 – The unique end caps conceal the wiring and input cables,
giving the amplifier a clean “stealth” look.

Left
Gain

6 6

Left

Input

Right
Input

Right
Gain

Bass

3

8

+R–+L–

3 8 7 7

Speaker Speaker

Treble

49 5

LED

REM

GNDB+

3. Speaker Terminals – The heavy duty, gold-plated terminal block
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 gold-plated spade terminal is used for the auto
power/remote turn on of the Punch amplifier.

6. RCA Input Jacks – The industry standard RCA jacks provide easy
connections for signal level input. They are gold-plated to resist the
signal degradation caused by corrosion.

– 5 –

7. Input Sensitivity Controls – The input level controls are preset to

match the output of most source units. They can be adjusted to match
output levels from a variety of source units.

8. Punch Equalization Controls – The Punch EQ helps correct for

acoustical deficiencies in the listening environment. The Bass control
allows a narrow band adjustment of up to 18dB centered at 45Hz. The
Treble control is a wide band hinged adjustment with a maximum of
12dB at 20kHz. The Punch EQ can be bypassed by turning the
controls to their minimum or counterclockwise position.

9. LED Power Indicator – The LED illuminates when the unit is turned on.

10. XCard (Internal Crossover) – This built-in crossover card is

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.

®

27.5 Watts RMS continuous power per
channel into 4 Ohms with less than 0.08%
Total Harmonic Distortion from 20-20kHz

High-Pass

AMPLIFIER

®

ROCKFORD CORPORATION

MADE IN THE USA

HP

LP

10

Low-Pass

LP

HP

Full Range

FULL

+

L+ R–

For Bridged Mono Wiring

Connect 4Ω mono woofer + to L+ of amplifier

and mono woofer – to R– of amplifier. Amplifier

will operate mono/stereo simultaneously.

Do Not Chassis

Ground Any Speaker.

–

– 6 –

I

NSTALLATION

The following is a list of tools you will need for installing the Punch amplifier:
Allen wrenches 9/64" & 3/32" (included) Voltmeter
Wire strippers Battery post wrench
Electric hand drill w/assorted bits Wire cutters
17' (518.16cm) Red Power Wire Assorted connectors
12' (365.76cm) Remote Turn-On Wire Wire crimpers

1.5' (45.72cm) Black Grounding Wire
This section focuses on some of the vehicle considerations for installing your

new Punch amplifier. Checking your battery and present sound system, as
well as pre-planning your system layout and 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.

Before beginning any installation, be sure to follow these simple rules:

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. Think before you drill! Be careful not to cut or drill into gas tanks, 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 wires over or through sharp edges. Use rubber or 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 appropriate 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. Grounding connec­tions should be as short as possible and always be connected to metal
that is welded to the main body, or chassis, of the vehicle.

C

ONSIDERATIONS

– 7 –

M

OUNTING LOCATION

The mounting location and position of your amplifier will have a great effect
on its ability to dissipate the heat generated during normal operation. The
design of our cast aluminum heatsink serves to easily dissipate the heat
generated over a wide range of operating conditions. However, to maximize
the performance of your amplifier, 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.

Mounting the amplifier on the floor of the trunk will work but provides less
cooling capability than vertical mounting.

Mounting the amplifier upside down to the rear deck of the trunk will not
provide proper cooling and will severely affect the performance of the
amplifier and is strongly

Passenger Compartment Mounting

Mounting the amplifier in the passenger compartment will work as long as
you provide a sufficient amount of air for the amplifier to cool 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.

not

recommended.

Mounting the amplifier with less than 1" (2.54cm) of air gap around the
amplifier's heatsink in the passenger compartment will not provide proper
cooling and will severely affect the performance of the amplifier and is
strongly

not

recommended.

Engine Compartment Mounting

Rockford Fosgate amplifiers should
compartment. Not only will this void your warranty but could create an
embarrassing situation caused by the ridicule from your friends.

– 8 –

never

be mounted in the engine

B

ATTERY AND

C

HARGING

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 and an energy storage
capacitor.

W

IRING THE SYSTEM

CAUTION:

Avoid running power wires near the low level input cables,
antenna, power leads, sensitive equipment or harnesses. The power
wires carry substantial current and could induce noise into the audio
system.

• For safety, disconnect the negative lead from the battery prior to beginning
the installation.

1. Configure the internal XCard crossovers prior to installation. Refer to

“Using the XCard” (page 14) for further information.

2. Plan the wire routing. Take care when running signal level RCA cables

to keep them close together but isolated from the amplifier'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.

3. Prepare the Power cable for attach-

ment to the amplifier by stripping 5/8"
of insulation from the end of the wire.
To prevent the wire from fraying, strip
the insulation at a 45° angle. Insert
the bared wire into the B+ terminal

STRIP WIRE

AMP

>

5/8"

>

INSULATION

>

><

with the long side of the insulation on
the top. Bend the cable down at a 90°
angle. Tighten the set screw to secure
the cable in place.

– 9 –

Punch 55.2, 75.2, 125.2

Trim the power cable to within 18" of the battery and install the protective
rubber boot, which is packed with the fuseholder, over the end of the wire.
Strip 3/8" of insulation from the wire and insert into the end of the
fuseholder, then crimp it in place. Slide the rubber boot into place to cover
the connection. Use the section of cable that was trimmed earlier and
connect it to the other end of the fuseholder.

Punch 225.2

Mount the fuseholder within 18" of the battery using two (2) #8 screws.
Disassemble the fuseholder. You should have 2 black plastic end caps,
2 gold-plated fuse clips, a plastic spacer and the fuseholder body. Trim
the amplifier power cable to reach the fuseholder and strip the wire 3/8".
Slide one of the end caps over the wire (narrow end first) and insert the
wire into one of the fuse clips. Tighten the set screw. Screw the black end
cap to the fuseholder body to secure the cable. Use the section of cable
that was trimmed earlier and connect it to the other end of the fuseholder.
Install the plastic spacer in the fuseholder and attach the cable to the
fuseholder body.

NOTE: The B+ cable MUST be fused 18" or less from the vehicle's
battery. Install the fuseholder under the hood and prepare the cable
ends as stated above. Connections should be water tight.

4. Strip 3/8" from the battery end of the power cable and crimp a large ring
terminal to the cable. Use the ring terminal to connect to the battery
positive terminal. Do not install the fuse at this time.

5. Prepare a length of cable to be used for the ground connection. Strip
5/8" of insulation from the end of the cable as described previously
and connect to the appropriate terminal of the amplifier. Prepare the
chassis ground by scraping any paint from the 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
non-anodized screw and a star washer.

6. Prepare the REM turn-on wire for connection to the amplifier by stripping

1/4" of insulation from the wire end and crimping an insulated spade
connector in place. Slide the connector over the REM terminal on the

– 10 –

amplifier. Connect the other end of the REM wire to a switched 12 volt
positive source. The switched signal is usually taken from the source
unit's auto antenna or the accessory lead. If the source unit does not have
these outputs available, the recommended solution is to wire a mechani­cal switch in line with a 12 volt source to activate the amplifier.

7. Securely mount the amplifier (with supplied screws) to the vehicle or

amp rack. Be careful not to mount the amplifier on cardboard or plastic
panels. Doing so may enable the screws to pull out from the panel due
to road vibration or sudden vehicle stops.

8. Connect the source signal to the amplifier by plugging the RCA cables

into the input jacks at the amplifier.

9. Connect the speakers. Strip the speaker wires 5/8". Insert the bared wire

into the speaker terminal and tighten the set screw to secure into place.
Be sure to maintain proper speaker polarity.

DO NOT chassis ground

any of the speaker leads as unstable operation may result.

10. Perform a final check of the completed system wiring to ensure that all

connections are accurate. Check all power and ground connections for
frayed wires and loose connections which could cause problems.

11. 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 neighborhood. 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 successfully completed
another upgrade to your audio system for which they will probably spill
thumbtacks on your driveway.

– 11 –

U

SING PASSIVE CROSSOVERS

A passive crossover is a circuit that uses capacitors and/or coils and is placed
on speaker leads between the amplifier and speaker. The crossover delegates
a specific range of frequencies to the speaker for optimum driver performance.
A crossover network can perform one of three functions: High-Pass (capaci­tors), Low-Pass (inductors or coils) and Bandpass (combination of capacitor
and coil).

The most commonly used passive crossover networks are 6dB/octave
systems. These are easy to construct and require one component per filter.
Placing this filter in series with the circuit will reduce power to the speaker by
6dB/octave above or below the crossover point depending on whether it is a
high-pass or low-pass filter. More complex systems such as 12dB/octave or
18dB/octave can cause impedance problems if not professionally designed.

Passive crossovers are directly dependent upon the speaker's impedance and
component value for accuracy. When passive crossover components are
used in multiple speaker systems, the crossover's effect on the overall
impedance should be taken into consideration along with the speaker's
impedance when determining amplifier loads.

fiers are not recommended for impedance loads below 2Ω stereo and 4Ω
bridged (mono) loads.

CAUTION: The Punch ampli-

a

O
p

d

e

v

r

a

a

n

t

c

i

e

o

d

n

– 12 –