B4R Bass Amplifier

Troubleshooting

In the unlikely event that your B4R should malfunction, take a few minutes to troubleshoot it before you call for ser- vice. You can save yourself time and money by doing it yourself, and often the problem is something quite simple.

NO SOUND

 

 

LEDs LIGHT

 

 

 

 

LEDs DON'T LIGHT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Check amp controls, check

 

 

 

 

Check AC outlet

 

 

 

 

for signal from bass

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OUTLET OK

 

NO POWER

 

 

NO SOUND

 

 

SOUND OK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Check power cord,

 

Check house fusebox

Listen for hum

 

 

 

fuse, power switch

 

or circuit breaker

NO HUM

HUM

OK

Check speaker

 

 

 

Unplug bass,

 

 

 

 

 

 

 

touch tip of cable

 

 

 

 

 

 

 

Speaker OK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NO CHANGE

 

 

 

 

SOUND OK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Replace cable

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NO CHANGE

SEE BELOW

 

 

POOR SOUND

 

 

 

 

 

 

 

 

 

 

 

 

 

Check bass, cables

 

 

 

 

 

 

 

 

 

 

 

 

 

 

POOR SOUND

 

 

 

SOUND OK

 

 

 

 

 

 

 

 

 

 

Check speaker(s)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SPEAKER(S) OK,

 

SPEAKER(S)

 

 

POOR SOUND

 

DEFECTIVE

 

Replace speaker(s)

POOR SOUND SOUND OK

SEE BELOW

If the problem isn’t covered above, or if the steps lead you here, then contact your Ampeg dealer for service informa- tion. Also, you should refer your amp to an authorized service center if it gets dropped, has liquid spilled into it, or sustains damage to its power cord (see page 2).

System Block Diagram

 

 

PEAK

 

 

 

LED

 

 

 

TUNER

 

 

 

OUT

 

0dB

 

 

 

INPUT

 

 

 

 

 

MUTE

 

 

 

 

GAIN

-15dB

 

 

 

INPUT

 

 

 

 

 

BI-AMP

 

 

UNBAL

 

 

 

LINE OUT

 

PRE

 

FREQ

BAL

 

BAL

 

 

 

 

 

LINE

LINE

 

POST

OUT

 

OUT

 

 

 

 

PRE/

 

 

 

POST

GROUND

 

 

 

LIFT

 

 

 

LEVEL

 

MASTER

 

 

 

 

EFFECTS

 

 

 

SEND

 

EFFECTS

 

 

 

MIX

 

 

 

 

 

EFFECTS

 

 

 

RETURN

 

 

 

BIAMP

TEXTURE

 

 

TONE CIRCUITS

 

 

 

 

9 BAND

 

GRAPHIC

BASS ULTRA MID TREBLE

 

EQ

 

 

 

 

(X9)

STYLE

f

LEVEL

 

(SLIDERS)

HIGH

 

 

OUT

 

 

LIMIT

 

SPKR

DEFEAT

 

 

POWER

OUT

LOW

(A)

AMP A

 

OUT

 

 

 

LIMITER

 

SPKR

 

 

OUT

 

 

(A)

 

POWER

 

BRIDGE MONO

AMP IN

 

 

(A/MONO)

 

STEREO

PREAMP

 

 

 

LIMIT

OUT

 

(A/MONO)

 

LED

 

 

 

 

SPKR

STEREO/

POWER

OUT

(B)

BRIDGED

AMP B

 

LIMITER

 

SPKR

 

 

OUT

 

 

(B)

BRIDGE

POWER

 

MONO

AMP IN

 

 

(B)

 

STEREO

PREAMP

 

 

 

 

OUT

 

 

(B)

 

EQ IN

"DOMESTIC"

BINDING

 

 

POSTS

 

 

(A)

 

 

RED

 

 

(+)

 

 

BLK

 

 

(–)

"EXPORT"

 

 

1+

 

1–

2–

SPEAKON®

 

JACK

 

 

(A)

 

2+

 

 

1+

SPEAKON®

 

 

1–

2–

JACK

(MONO

 

 

 

 

BRIDGE/

 

2+

BIAMP)

 

 

 

1+

 

1–

2–

SPEAKON®

 

JACK

BINDING

 

(B)

POSTS

2+

 

(B)

 

RED

 

 

(+)

 

 

BLK

 

 

(–)

 

 

Speakon®

is a registered trademark of Neutrik AG.

11

FULL RANGE

 

Page 11
Image 11
Ampeg B4R manual Troubleshooting, System Block Diagram