Ampeg Bass Combo B2 User Manual

							Owner’s Guide
for the
B2/B2R
Bass Amplifier
Made in the U.S.A.by 
						

							2T
ABLEOFCONTENTS
Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Features  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Important Safeguards and Precautions  . . . . . . . . . .3
The Front Panel Controls and Their Use  . . . . . . . .4
The Rear Panel  . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Some Suggested Settings  . . . . . . . . . . . . . . . . . . .6
Rack Mounting (B2R only)  . . . . . . . . . . . . . . . . . . .6
Troubleshooting  . . . . . . . . . . . . . . . . . . . . . . . . . . .7
System Block Diagram  . . . . . . . . . . . . . . . . . . . . . .7
Technical Specifications  . . . . . . . . . . . . .back cover
Thank youfor making one of the best choices you will ever make for your musical career – choosing one of the
finest bass amplifiers available, the Ampeg B2/B2R.
Whether you’ve purchased the portable B2 combo system or the two-space rack-mountable B2R head version,
your new B2/B2R bass amplifier provides many outstanding features. Three hundred and fifty watts of pure bass
energy, total tone control and rugged construction make each one a true performer’s bass amp.
In the world of high performance bass amps, Ampeg’s SVT amplifiers stand alone. In true Ampeg tradition,
the B2/B2R offers you more power, performance and flexibility than any other bass amplifier in its class. The
outstanding features of your new amplifier, features which set it apart from the competition, are listed below. 
•9-BAND GRAPHIC EQ:Use as a “second channel” for bass solos, or to shape your sound to your
own exacting standards. 
•BALANCED LINE OUTPUT:XLR with independent level switch (20dB pad). Patch into house
consoles, mixing boards, or external power amplifiers.
• EFFECTS LOOP:For increased intensity and quieter operation of external effects.
• POWER AMP IN and PREAMP OUT:Allows direct access into the power amp and a signal tap
from the preamp section for even greater versatility.
• MUSICIAN MADE IN THE U.S.A.
An introduction To Your New Ampeg B2/B2R Bass Amplifier
B2/B2R Bass Amplifier
Features 
						

							3
CAUTIONRISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER.
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
ATTENTIONRISQUE DELECTROCUTION
NE PAS OUVRIR
ATTENTION: POUR REDUIRE DELECTROCUTION NE PAS
ENLEVER LE COUVERCLE. AUCUNE PIECE INTERNE NEST REPRABLE
PAR LUTILISATEUR. POUR TOUTE REPARATION, SADRESSER A UN
TECHNICIEN QUALIFIE.
VORSICHTELEKTRISCHE SCHLAGGEFAHR
NICHT OFFENEN
VORSICHT: ZUR MINIMIERUNG ELEKTRISCHER SCHLAGGEFAHR NICHT
DEN DECKEL ABENHMEN. INTERNE TEILE KONNEN NICHT VOM
BENUTZER GEWARTET WERDEN. DIE WARTUNG IS QUALIFIZIERTEM
WARTUNGSPERSONAL ZU UBERLASSEN.
THIS EQUIPMENT HAS BEEN DESIGNED AND ENGINEERED TO PROVIDE SAFE AND RELIABLE OPERATION. IN ORDER TO PROLONG THE LIFE OF THE UNITAND PREVENT ACCIDEN-
TAL DAMAGES OR INJURY, PLEASE FOLLOW THESE PRECAUTIONARY GUIDELINES:
WARNING:TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT OPEN CHASSIS; DO NOT DEFEAT OR REMOVE THE GROUND PIN OF THE POWER CORD; CONNECT ONLY TO A PROP-
ERLY GROUNDED AC POWER OUTLET.
CAUTION:TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
CAUTION:NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
CAUTION:OUR AMPLIFIERS ARE CAPABLE OF PRODUCING HIGH SOUND PRESSURE LEVELS. CONTINUED EXPOSURE TO HIGH SOUND PRESSURE LEVELS CAN CAUSE PERMANENT
HEARING IMPAIRMENT OR LOSS. USER CAUTION IS ADVISED AND EAR PROTECTION IS RECOMMENDED IF UNIT IS OPERATED AT HIGH VOLUME.  The chart below shows the U.S.
Government Occupational Safety and Health Administration (OSHA) regulations which were in effect at the time of this publication for permissible noise exposure, per 29CRF1910, Table G-16.
According to OSHA, any exposure in excess of those listed above could result in some hearing loss.
IT IS NECESSARY FOR THE USER TO REFER TO THE INSTRUCTION MANUAL
REFERREZ-VOUS AU  MANUAL DUTILISATION
UNBEDINGT IN DER BEDIENUNGSANLEITUNG NACHSCHLAGEN EXPLANATION OF
GRAPHICAL SYMBOLS:
DANGEROUS VOLTAGE
DANGER HAUTE TENSION
GEFAHLICHE SPANNUNG=
=
SOUND LEVEL dBA DURATION PER DAY
SLOW RESPONSE IN HOURS
90 8
92 6
95 4
97 3
100 2SOUND LEVEL dBA DURATION PER DAY
SLOW RESPONSE IN HOURS
102 1-1/2
105 1
11 0 1 / 2
115 1/4 or less
B2/B2R Bass Amplifier
Important Safeguards and Precautions
All Ampeg products are designed for continuous, safe operation, as long as common sense is used and
steps are taken to help avoid certain problems. Abiding by the following rules can help prevent damage to
your amplifier, yourself and others. 
•The amplifier is equipped with a three-pronged  AC power cord. To reduce the risk of electrical shock,
NEVERremove or otherwise attempt to defeat the ground pin of the power cord.
•Connect the amplifier ONLYto a properly grounded AC outlet of the proper voltage for your  amp. 
•Avoid sudden temperature extremes, rain and moisture. Also, avoid sudden and intense impact. (If
the unit has been subjected to any of the preceding abuses, have it looked at by an authorized ser-
vice center.)
•NEVERset the amplifier on a support that might give out under its weight.
•Whenever using tall or stacked speaker cabinets, use them ONLYon a level surface. NEVERset tall
or stacked cabinets on a surface with more than a five degree incline since tipping or falling could
occur, possibly causing serious injuries.
•Always keep the total speaker impedance at or above the rated load.
•Unplug the amplifier before cleaning it. NEVER spray liquid cleaners onto the amplifier. Wipe it with
a slightly dampened, lint-free cloth to remove dirt and film.
•Don’t use the amplifier if it has sustained damage to the chassis, controls, or power cord. Refer the
unit to an authorized service center for inspection.
•Amplifiers capable of producing high volume levels are also capable of inflicting permanent hearing
loss or damage, if the exposure to such levels is prolonged. Such damage is progressive and irre-
versible!  
						

							4
The Front Panel Controls and Their Use
B2/B2R Bass Amplifier
0 +12dB
-12dB 40Hz 8kHz5kHz 2kHz 900Hz 600Hz 300Hz 150Hz 80Hz
EQ LIMIT PEAK -15dB
ON
GAIN PAD BASS ULTRA MID TREBLE MASTER LIMITER INPUT
ON
POWER
0
12876541091131213
1. 0dB (INPUT):The signal output from an
instrument (active or passive) or a line level
signal may be connected here by means of
a shielded instrument cable.
2. 15dB PAD:This switch, when
depressed, attenuates the input signal by
15dB. Attenuation allows the Gain control
(#4) to be used over a larger portion of its
range. If clipping is indicated with the Gain
control near minimum, attenuation is need-
ed.
3. PEAK LED: This LED flashes when the
signal level into the preamp approaches
clipping. Adjust the Gain control (#4) until a
strong signal from your instrument causes
this LED to flicker.
NOTE:If the LED flashes frequently with
the gain at a low setting, use the 15dB Pad
(#2) to attenuate the input signal and read-
just the Gain.
4. GAIN:This serves as the input level
control for the amplifier. For the best signal-
to-noise ratio set this control so the Peak
LED (#3) flashes when you strike a string
fairly hard.
5. BASS:This is the primary low frequency
control which allows for 8dB of cut or boost
at 50Hz.6. ULTRA-MID:This is the primary
midrange control. Rotate the control to the
left of center for a “contoured” sound (more
distant, less midrange output) or to the
right of center for a pronounced (more up-
front) tone.
7. TREBLE:This is the primary high fre-
quency control which allows for 12dB of
boost or 19dB of cut at 5kHz.
8. MASTER:Set the overall output level of
the amplifier with this control. The Effects
Loop and Balanced Out (#19-21,24) are
not affected by the Master control.
9. LIMITER:The B2/B2R uses an internal
Optocoupler Limiter to assist in keeping the
power amplifier’s output “clean” at extreme
volume levels. (All amplifiers begin to clip
their output signals as they approach maxi-
mum output levels, resulting in distortion
which may damage your speakers.) To
engage the Limiter, depress the Limit
switch. Whenever the amplifier is at full
power, the adjacent LED will flash. This is
an indication that the limiter is keeping peak
signals from clipping the output.
NOTE:Playing at full power with the Limiter
off will give you increased output power, but
the sound may be distorted. Use discretion
when playing without the Limiter.10. EQ ON SWITCH:Depress this switch
to activate the Graphic EQ. The adjacent
LED illuminates when the EQ is on.
11. GRAPHIC EQ:These sliders control
the output of the frequencies indicated
above each control. The center position of
each control is flat (no boost or cut).
12. POWER ON LED:This LED indicator
illuminates when the POWER switch (#13)
is ON.
13. POWER SWITCH:This heavy-duty
rocker switch applies the power to the
amplifier. The amp is ON when the top of
the switch is depressed, OFF when the
bottom of the switch is depressed. 
						

							5
The Rear Panel
B2/B2R Bass Amplifier
MODEL:
SERIAL:
    LINE:         V ~          Hz
WATTS:             MAXB2R
Q2ZZ650022
120     60  
 
15161819202123 24221417
14. FAN:This temperature controlled, vari-
able speed fan draws cool air into the
amplifier, which forces heat out through the
exhaust vents. Never block the vent holes
or the fan opening.
15. FUSE:This protects the unit from dam-
age due to overload conditions or power
line surges. If the fuse blows, replace it
only with the same size and type.
16. AC LINE IN:Firmly insert the supplied
AC power cord into this socket until it is
fully seated. Plug the male end of the cord
into a grounded AC outlet. DO NOT
DEFEAT THE GROUND PRONG OF THE
AC PLUG!
17. SPEAKER OUTPUTS:Use these
jacks to connect the amplifier to your
speaker(s) using cables terminated with
1/4” connectors. For the B2 combo, use the
supplied speaker cable to connect the out-
put of the amplifier to the speaker jack. An
extension speaker with an impedance of 8
ohms or higher may be connected and
allows the amplifier to deliver its maximum
power.
NOTE: In some areas 1/4” jacks are not
acceptable for use as extension speak-
er jacks. For this reason the 1/4” jacks
on your amplifier may be factory-sealed.
In such cases use the Speakon
®jack to
connect to external speaker cabinets.For the B2R, connect the output(s) using
high quality speaker cables.
NOTE:When connecting multiple
speaker cabinets to the B2/B2R, keep
the overall impedance at or above four
ohms!The following chart shows the total
impedance load when connecting speaker
cabinets in parallel:
18. POWER AMP IN:This mono jack
allows you to feed the preamp output of
another amplifier to the input of the
B2/B2R’s internal power amp. This bypass-
es the preamp circuitry of the B2/B2R.
WARNING: This jack goes directly into
the power amplifier. DO NOT connect
high level signals to it!
19. PREAMP OUT:A post-EQ signal may
be taken from this jack and sent to the
house mixing board, recording console or
external power amplifier.
20. EFFECTS RETURN:To use an exter-
nal effects device, connect the OUTPUT of
the device to this jack by means of a shield-
ed cable. This feeds the processed signal
into the Master section of the B2/B2R.21. EFFECTS SEND:Connect the output
from this jack to the INPUT of your effects
by means of a shielded cable. This sends a
post-EQ signal to your effects.
22. -20dB SWITCH :This switch adjusts
the output level at the Balanced Line
Output jack (#24). The control works inde-
pendently from the front panel Master con-
trol. Depressing the switch activates the
20dB pad. The result is a signal that is
more compatible with the microphone
inputs on a mixer.
23. PRE/POST SWITCH:You can select
either Pre or Post EQ for the signal at the
Balanced Out jack (#24) with this switch.
With the switch in the OUT position, the
signal at the jacks will be Pre-EQ. This is a
direct output not affected by any EQ or
boost settings. With the switch depressed,
the signal is Post-EQ and is controlled and
modified by the tone controls, Graphic EQ,
and Effects Loop.
24. BALANCED OUTPUT:This XLR-type
connector supplies a balanced preamp out-
put signal for connecting to a house mixing
board, recording console or external ampli-
fiers with balanced inputs. The signal can
be set to Pre or Post EQ by the back panel
Pre/Post switch (#23). The level can be
adjusted for either mic or line type inputs
using the -20dB switch (#22).
Cabinet # of Total
Impedance Cabs Impedance
8Ω24Ω
16Ω28Ω
16Ω44Ω
Speakon®is a registered trademark of Neutrik USA 
						

							PEAK -15dB
GAIN PAD BASS ULTRA MID TREBLE MASTER
PEAK  -15dB
GAIN PAD BASS ULTRA MID TREBLE MASTER
PEAK  -15dB
GAIN PAD BASS ULTRA MID TREBLE MASTER
PEAK  -15dB
GAIN PAD BASS ULTRA MID TREBLE MASTER
6
Some Suggested Settings
Rack Mounting (B2R only)
JAZZ: ROCK:
COUNTRY:
FUNK “POPPING:”B2/B2R Bass Amplifier
The setting of the Gain control depends on your particular instrument. The
Master should be set to produce the appropriate output volume level. The
Graphic EQ can be used to tailor the amplifier to your speaker cabinets, to
compensate for room acoustics and to “fine tune” your sound.
When mounting the B2R into a rack, the four bottom feet should be removed to maintain the two rack space height of the amplifier. Be
sure to keep the feet and their attachment bolts for future use. If the feet are reinstalled, never use screws which will protrude farther
into the amplifier than the original hardware. 
The rack must be a high quality enclosure capable of securely supporting the weight of the amplifier. Tighten the mounting screws
securely through the amplifier’s face plate, into the rack rails. Check the rack and mounting screws occasionally to ensure a continual-
ly safe and secure installation. 
						

							7 B2/B2R Bass Amplifier
Troubleshooting
In the unlikely event that your B2/B2R should malfunction, take a few minutes to troubleshoot it before you call for ser-
vice. You can save yourself a lot of time and sometimes money by doing it yourself, and often the cure for the problem
is something quite simple. 
If the problem isn’t covered above, or if the steps lead you here, then contact your Ampeg dealer for service infor-
mation. Also, you should refer your amp to an authorized service center for servicing if it gets dropped, has liquid spilled
into it, or sustains damage to its power cord (see page 3).
System Block Diagram
NO SOUND
LEDs LIGHT
POOR SOUND
Check bass, cables
Check speaker(s)
Replace speaker(s)
POOR SOUND
LEDs DONT LIGHT
Check AC outlet
NO SOUND
NO HUMHUM
Listen for hum
NO CHANGE
SOUND OK
SOUND OK
POOR SOUNDSOUND OK
SOUND OK
SOUND OK
Check amp controls, check
for signal from bass
Check power cord,
fuse, power switchCheck house fusebox
or circuit breakerSPEAKER(S) OK,
POOR SOUNDSPEAKER(S)
DEFECTIVE
Check speaker Unplug bass,
touch tip of cable
LOUD HUM
Check inst. pickup
Speaker OK
Replace cable
NO CHANGE
SEE BELOWSEE BELOW
NO POWEROUTLET OK
OK
INPUT
-15dB
-20dB
LIMIT
ON LIMIT
LED
POWER
AMPPROTECTION
RELAYSPEAKON
®JACK
SPEAKER
OUTPUT
SPEAKER
OUTPUT
POWER
AMP IN
PREAMP
OUT
EFFECTS
RETURN
EFFECTS
SEND
THERMAL
SHUTDOWN,
LOW VOLTAGE,
DC PROTECT
COOLING
FAN BALANCED
LINE OUT PRE
POST
EQMASTERGAIN
ON
9 BAND EQ
PEAK LED
BASS TREBLE
ULTRA MID 
						

							Ampeg reserves the right to change specifications without notice.
Ampeg is proudly Made in America. ©1999 SLM Electronics, 1400 Ferguson Avenue, St. Louis, MO 63133 U.S.A.
P/N 47-577-03 • 10/99
B2/B2R Bass Amplifier
Technical Specifications
OUTPUT POWER RATING350 Watts RMS, 4 ohm load, 120VAC
200 Watts RMS, 8 ohm load, 120VAC
POWER REQUIREMENTS
Domestic:120VAC, 60Hz, 310VA
Export:100/120VAC, 50/60Hz, 310VA
230-240VAC, 50/60Hz, 310VA
TONE CONTROL RANGE
Bass:±8dB @ 50Hz
Ultra Mid:±8dB @ 500Hz
Treble:+12dB/-19dB @ 5kHz  
GRAPHIC EQ RANGE
40Hz:±11dB
80Hz:±8dB
150Hz:±8dB
300Hz:±8dB
600Hz:±8dB
900Hz:±8dB
2kHz:±8dB
5kHz:±9dB
8kHz:±12dB
GAIN45dB typical, tones @ center
SIGNAL TO NOISE RATIO75dB typical
INTERNAL SPEAKER (B2 ONLY)
Size/Type:15” Ampeg Custom (1)
Magnet:56 oz.
Voice Coil:2.5”
Impedance:8 ohms
SIZE AND WEIGHT
B2:24” W x 24.5” H (26.5” w/casters) x 16” D; 87 lbs.
B2R:19” W x 1.75” H x 12.75” D; 15 lbs.
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