WorkingPro™ 12
COMBO AMPLIFIER

Important Safety Instructions
ENGLISH - PAGES . . . . . . . . . . . 6-10
This symbol warns the user of dangerous voltage levels localized within theenclosure.

This symbol advises the user to read all accompanying literature for safe
operation of the unit.
∆ Read, retain, and follow all instructions. Heed all warnings.

ESPAÑOL- PAGINAS . . . . . . . 11-15∆ Only connect the power supply cord to an earth grounded AC receptacle in accordancewith the voltage and frequency ratings listed under INPUT POWER on the rear panel ofthis product.
∆ WARNING: To prevent damage, fire or shock hazard, do not expose this unit to rain ormoisture.
∆ Unplug the power supply cord before cleaning the unit exterior (use a damp cloth only).
Wait until the unit is completely dry before reconnecting it to power.

FRANÇAIS - PAGES . . . . . . . . . . 16-20∆ Maintain at least 6 inches (15.25 cm) of unobstructed air space behind the unit to allow
for proper ventilation and cooling of the unit.
∆ This product should be located away from heat sources such as radiators, heat registers,or other products that produce heat.
∆ This product may be equipped with a polarized plug (one blade wider than the other).
This is a safety feature. If you are unable to insert the plug into the outlet, contact anelectrician to replace your obsolete outlet. Do not defeat the safety purpose of thisplug.
∆ Protect the power supply cord from being pinched or abraded.

ITALIANO- PAGINE . . . . . . . . 21-25∆ This product should only be used with a cart or stand that is recommended by themanufacturer.
∆ The power supply cord of this product should be unplugged from the outlet when left
unused for a long period of time, or during electrical storms.
∆ This product should be serviced by qualified service personnel when: the power supply
cord or the plug has been damaged; or objects have fallen, or liquid has been spilled onto
the product; or the product has been exposed to rain; or the product does not appear tooperate normally or exhibits a marked change in performance; or the product has been
dropped, or the enclosure damaged.

DEUTSCH - SEITEN . . . . . . . . . . 26-30∆ Do not drip nor splash liquids, nor place liquid filled containers on the unit.
∆ CAUTION: No user serviceable parts inside, refer servicing to qualified personnel only.
∆ SWR® amplifiers and loudspeaker systems are capable of producing very high soundpressure levels which may cause temporary or permanent hearing damage. Use carewhen setting and adjusting volume levels during use.
∆ Hazardous voltages may be present within the cabinet even when the power switch is off andthe power cord is connected. Therefore, disconnect the power cord from the rear panel power
inlet before servicing. The power inlet must remain readily operable.

PORTUGUÊS - PAGINA . . . . . . 31-35. . . . . . . . . . . . . 36-40

SWR® WorkingPro™ 12 Combo Amplifier
Congratulations on your purchase of an SWR WorkingPro 12
combo amplifier! You now own the famous SWR tone, power,
clarity, and true full-range response that’s made SWR the choiceof professionals for over twenty years. Your WorkingPro 12
combines the best SWR features:• The famous preamp designed by original engineer Steve W.
Rabe• Aural Enhancer™ and Active EQ controls• Bass Intensifier™ circuit—simultaneously boosts andcompresses specific frequencies to add pure low-end
thickness to your bass sound• New Wedge EQ specially designed for amp "tilt-back"
operation• Side-mounted monitor input converts the WorkingPro intoa powered stage monitor or auxiliary input for your CD/MP3
playerSince our founding in 1984, SWR has served one purpose—toprovide bass amplification products with professional quality,
tone, features and power delivery for players of all levels andstyles. We sincerely thank you for choosing SWR, and remaincommitted to helping you Amplify Your Future™.
Read through this Owner’s Manual before using yourWorkingPro amplifier to take advantage of the full potential ofyour WorkingPro amplifier and to ensure the safe operation ofyour investment!

Front Panel

A. INPUT—Plug your bass into this jack using ashielded instrument cable.
B. INPUT PAD—Reduces input sensitivity to allow cleaner
response from high-output (above 1-Volt RMS) bass guitars. Use the setting that sounds best!
NORMAL—Full input sensitivity–10dB PAD—Lower input sensitivity
For active (pre-amplified) bass guitars: If you hear distortion—even with -10dB INPUT PAD selected and a low
GAIN {D} (PREAMP CLIP not flashing)—check your guitar
battery.

D. GAIN—Preamp volume control. Use GAIN primarily tocontrol signal distortion, then use MASTER Volume {K} toadjust the loudness of the amplifier. GAIN also sets theEFFECTS SEND {Q} output level, allowing you to matchthe input sensitivity of your effects unit. Use the PREAMP
CLIP LED to find the desired GAIN setting:PREAMP CLIP—Indicates when the preamp is being
overdriven (clipping), causing signal distortion. Adjust
GAIN until PREAMP CLIP flashs slightly at the peak
input levels from your instrument to get the maximum
power with the least distortion from the WorkingPro.
NOTE: Preamp clipping is not harmful to the amplifierand can be used for effect.

C. MUTE—Disables the amplifier's audio outputs except
TUNER {T}, EFFECTS SEND {Q} and HEADPHONES {P} which
remain active. Use MUTE during: instrument changes,LED inditune-ups and when using headphones. Thecates when MUTE is engaged.

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Front Panel
E. AURAL ENHANCER—Featured on just about every SWR
amplifier since the company’s inception in 1984, the AuralEnhancer delivers that famous SWR Sound! It brings out
the fundamental low notes of the bass guitar, enhances
the high-end transients, and reduces specific frequencies that mask the fundamentals. This provides a moretransparent sound, particularly when slapping and popping and also gives "active" bass characteristics to passive basses (when set at “2 o’clock” or positions furtherclockwise).

H. BASS INTENSIFIER™—Exclusive SWR® tone circuit that
integrates low-frequency boost with a smooth, fast-acting
compressor. This provides a radical increase of specificbass and low-midrange frequencies without the usualside-effect of overdriving the amplifier circuitry. This literally intensifies the bass tone in your sound! Use it for
the heavier sections of a song, or as part of your overall
preferred sound.

How the AURAL ENHANCER Works: Think of it as a variable tone curve that changes depending on where you
set the AURAL ENHANCER control knob. As you rotate
the control clockwise from the “MIN” position, you areelevating low– mid– and high–frequencies different thanthose of the active tone controls. This remains true up to
about the “2 o’clock” position, a favorite of many players
because it brings out the low-end fundamentals and crisp
highs plus lower midrange to help cut through the band.
However, if you go further clockwise past the “2 o’clock”
position, the mids centered around 200 Hz will start todrop off. From this point on, the effect becomes much
more pronounced. However, the curves involved here aregentle, as opposed to the extreme curves you can createby boosting or cutting the active tone controls.

CUTOFF—Adjusts the frequency range boosted bythe BASS INTENSIFIER. When fully counter-clockwise,
only frequencies below ~80Hz are affected. When fullyclockwise, frequencies below ~200Hz are affected.

Most significantly for basses, the AURAL ENHANCER™ will
help bring out the fundamentals of your lower registers
without masking them with overtones, as is possible
when using the BASS control only. At the same time, itopens up the sibilance characteristics of all instruments
without being harsh.
F.

ACTIVE TONE CONTROLS—Shelving type, 3–band equalization:

ENGAGE—Activates the BASS INTENSIFIER circuit asindicated by the LED .

To best hear what the BASS INTENSIFIER does: 1. Decrease
MASTER Volume to half its normal setting (or less). 2. Set
LEVEL to maximum and CUTOFF to 80Hz. 3. Play a note
repeatedly and slowly rotate CUTOFF clockwise. You willhear frequencies being boosted as you turn the dial, andthe overall effect will seem louder as more frequencies
are boosted. Your ears are the best judge so take sometime to experiment and hear what works best.
I.

WEDGE EQ—Use this tone circuit preset when playing
the amplifier with the cabinet in the tilt-back position.
The Wedge EQ compensates for the acoustics lost withcabinet floor contact and the redirected tweeter horn.

J.

LIMITER—This circuit protects the power amp and speakers from damage by governing peak signal strength,
allowing you to play at maximum loudness levels safely.
DEFEAT turns the Limiter OFF.
DEFEATED (LIMITER OFF)

LIMITER ON• BASS—Adjusts low-frequency response ±15dB in the30Hz–150Hz range.

ACTIVE—Indicates exactly when the LIMITER circuit is
LIMITER is ON).
working (when• MID—Adjusts mid-frequency response ±15dB in the500Hz to 1kHz range.

POWER AMP CLIP—Alerts when the power amp signal
is being overdriven and distorting. Power amp clipping
can be harmful to equipment! Use the LIMITER or reduce
MASTER Volume {K} if POWER AMP CLIP flashes often.

• TREBLE—Adjusts high-frequency response ±15dB in the2kHz to 14kHz range.
G. EFX BLEND—Functional only when a plug is inserted
into the EFFECTS RETURN {Q} jack, this knob sets youreffects level by controlling the amount of "wet" effects
loop signal blended into the "dry" preamp signal.

K. MASTER VOLUME—Use to adjust the loudness of theWorkingPro after all other levels are set, including any
external effects. MASTER Volume affects the BALANCEDOUTPUT {U} and the UNBALANCED LINE OUT {S} levels
LINE. Select DIRECT
when DIRECT/LINE {U} is set towhen you do not want MASTER to change the signal level
output to sound equipment.
L. POWER SWITCH—Switches the unit ON-OFF as indicatedby the LED.

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7

Rear Panel

M. FUSE—Protects the amplifier from electrical faults.
Replace a blown fuse ONLY with a fuse of the type/rating
specified on the rear panel of your amplifier to protect
your amplifier and maintain warranty coverage.
N. IEC POWER CORD SOCKET—Connect the included
power cord to a grounded AC electrical outlet in accordance with the voltage and frequency ratings specified
above the input power socket on your amplifier.
O. SPEAKER OUTPUT—The internal speaker is connected
here. Unplug and connect an external speaker here ifdesired.
SPEAKER CONNECTIONS• DO NOT connect a speaker load with a total impedance
less than the minimum rating of your amplifier to prevent damage to your equipment. Read the Impedance
Guidelines section on page 10.
• ONLY connect speakers with a total power handling
capacity equal or greater than the power output ratingof your amplifier to prevent damage to your equipment.
• ALWAYS switch your system power OFF before connecting or disconnecting speakers.
• ONLY use unshielded speaker cable of 18 gauge orheavier (such as 16 or 14 gauge) for speaker connections. Shielded instrument cable WILL NOT work andmay damage your equipment.
P.

HEADPHONES—Plug in your stereo or mono headphones here. Use MASTER Volume to control your headphone listening level. Use MUTE {C} to disable speakeraudio output if desired. NOTE: 75-ohm headphones areideal for use with your WorkingPro.

8◊

Q. EFFECTS SEND / EFFECTS RETURN—Multi-purpose
jacks: EFFECTS SEND provides a preamp output that
includes the onboard tone adjustments; output levelis controlled by MASTER Volume {K}. EFFECTS RETURN
provides a power amp input that can be blended in any
ratio with the preamp signal using EFX BLEND {G}.
• EFFECTS LOOP—Connect EFFECTS SEND to your effects
device input, then connect the effects device output
to EFFECTS RETURN. NOTE: Set the wet/dry control
on external effects units to the fully WET position toprevent signal phasing problems. Set the input level on
external effects as close to 0dB as possible.
• MULTIPLE AMPS—Connect EFFECTS SEND on the first
amplifier to EFFECTS RETURN on the second amp. Use
only the controls on the first amplifier—except Master
Volume which will still be active on the second amp, as
well as EFX BLEND, which should be set fully to WET.
• RECORDING OR REINFORCEMENT—Connect EFFECTSSEND to sound equipment input.
• ACCOMPANIMENT—Connect a CD player or drum
machine to EFFECTS RETURN. Control the input levelat its source and by using the EFX BLEND control {J}.
Use only standard 1/4” mono phone plugs with thesejacks. Use a stereo–to–mono adapter if your source hasa stereo plug.
The Effects Loop circuit is on a “side chain” of the main
circuit (as in studio recording consoles) to provide thefull sound of your instrument AND the diversity of youreffects units. This also reduces noise from effects units
being located after gain in the signal path.
R. FOOTSWITCH—Plug in the optional footswitch here. Use
the footswitch to select MUTE and BASS INTENSIFIER™.

◊Rear Panel
S. UNBALANCED LINE OUT—Provides unbalanced preamp
output for an auxiliary amplifier or sound equipment(includes effects loop signal). Output level is controlled
by MASTER Volume {K}. DIRECT/LINE and PAD {U} also
affect this output.
T.

TUNER OUT—Plug in your bass guitar tuner here toenable inline tuning. Use MUTE {C} to disable audio output while tuning.

U. BALANCED (XLR) OUTPUT—A true electronically balanced output, suitable for studio and “front-of-house”(live) mixing consoles with three switching options:
DIRECT /LINE—Select DIRECT to supply theBALANCED OUTPUT and UNBALANCED LINE OUT jacks
with signal that bypasses the Tone and MASTER volume circuits. Select LINE to include these circuits.

GROUND /LIFT—Select GROUND for normal
operation. Select LIFT to disconnect the BALANCEDOUTPUT ground connection which may reduce hum
noise due a "ground loop" (non-standard XLR wiring).
NOTE: Lifting the ground connection will not solve
hum noise due to bad cables, poor connections,miswired A/C outlets, nearby fluorescent lighting(especially with single-coil pickups) or a cell phone
in your pocket.
0dB /–10dB—Select 0dB for normal operation.
Select –10dB to reduce the BALANCED OUTPUT andUNBALANCED LINE OUT ouput levels as needed tomatch the input sensitivity of the equipment you areconnecting to.

Monitor Input Panel
Y. LINE LEVEL MONITOR INPUT—Δ CAUTION! For line-level
inputs only! Δ Amplified (speaker level) inputs will damage
your equipment!
Insert a 1/4-inch plug from a line-level audio
source such as: • Line Out from another bass rig—expand
your output for larger venues, • Monitor Send froma mixing board—mix in some vocals or monitor themseparately, • Headphones Out on a CD/MP3 player—foraccompaniment (use a stereo-to-mono adapter to hear
both channels of your player.
MONITOR VOLUME—Adjusts the level of the MONITOR
INPUT signal. MASTER VOLUME {K} and MUTE {C} also
affect the Monitor Input.
Z. TWEETER LEVEL—Sets the output level of the piezo
tweeter for the amplifier (not just the Monitor Input).
Select: ON for maximum output, –6dB for 50% output,or OFF for to mute the tweeter.

◊◊9Impedance Guidelines
Before changing your speaker setup, a basic
knowledge of impedance ratings is essential tothe quality of your sound and to the safe operation of your equipment.

If impedances are different, the speakers with lower impedances will be much louder than the others. For example,
with an 8–ohm speaker and a 16–ohm speaker bothconnected to your amplifier, the 8–ohm speaker will betwice as loud (and get twice the power) as the 16–ohmspeaker. Calculating total power handling capacity andpositioning speakers of different impedances becomescomplicated!

The general rule is: if you connect a speakerload with a total impedance that's equal to theminimum impedance rating of your amplifier,you'll be OK—as long as the speakers are rated
to handle the power output from your amplifier.

Δ CAUTION!—Operating with a speaker load below
the minimum impedance rating of your amplifier
can easily overheat the amplifier and cause damage. Operating above the minimum impedance rating will reduce the amplifier’s maximum power output
potential.

The illustration shows the impedance totalsof different speaker combinations. NOTE: AllSWR® bass speaker enclosures, as well as mostothers, are wired "in parallel" (not series), therefore, this section applies to parallel speaker connections only.

For an in-depth discussion of impedance andpower rating issues go to the SWR Website atswrsound.com/support/setuptips.php—this article by
SWR founder Steve Rabe ran in the August ’92 issue of Bass
Player™ Magazine.

All speakers in a group should have the same
impedance so that each speaker will receive thesame amount of power from your amplifier.

Specifications
PART NUMBERS:

4452200010 (120V, 60Hz)
4452203010 (240V, 50Hz) AUS
4452204010 (230V, 50Hz) UK
4452206010 (230V, 50Hz) EUR4452207010 (100V, 50Hz) JPN

POWER REQUIREMENT:650W

POWER AMPMINIMUM IMPEDANCE:PRE AMPINPUT IMPEDANCE:

3.9M

SENSITIVITY AT FULL POWER:15mV

POWER OUTPUT:

TONE CONTROLSEFFECTS LOOP

4Ω200W RMS into 4Ω @ < 0.1% THD, 1kHz

BASS:

±15dB @ 100Hz

MID:±15dB @ 800Hz

TREBLE:±15dB @ 2kHz

SEND IMPEDANCE:

1.5kΩ

RETURN IMPEDANCE:

27kΩ

UNBALANCED LINE OUT

SEND IMPEDANCE:

1.5kΩ

BALANCED LINE OUT

SEND IMPEDANCE:

1.5kΩ

FOOTSWITCH (OPTIONAL):
LINE FUSE2-button, Mute, Bass Intensifier™ (P/N 065436)
100V MODELS:
120V MODELS:
230V-240V MODELS:

SPEAKERS:DIMENSIONS

F8A L, 250V
F6A L, 250V
F3.15A L, 250V
1 Eminence® 12'' 4Ω (071300)

HEIGHT:

22.5 in (57cm)

WIDTH:

18.5 in (47cm)

DEPTH:

18.5 in (47cm)

WEIGHT:

44lb (20kg)
Product specifications are subject to change without notice.

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A PRODUCT OF:
SWR MUSICAL INSTRUMENTS CORPORATIONCORONA, CALIFORNIA USA
SWR®, WorkingPro™, Aural Enhancer™ and Bass Intensifier™ are trademarks of FMIC.
Other trademarks are property of their respective owners.
© 2005 FMIC. All rights reserved.

P/N 064653 REV. A