5
OPERATION
1. Rotate 
MASTER
 to 
MIN
.
2. Press 
POWER
 up to turn on the
MPS-50. The POWER indicator
lights.
3. Adjust the sound for each channel
where you have connected an input
source.
• Rotate 
GAIN
 clockwise toward
MAX
 to increase the volume, or
counterclockwise toward 
MIN
 to
reduce it.
• Rotate 
BASS
 clockwise toward
MAX
 to increase the low fre-
quency sounds, or counterclock-
wise toward 
MIN
 to reduce them.
• Rotate 
TREBLE
 clockwise toward
MAX
 to increase the high fre-
quency sounds, or counterclock-
wise toward 
MIN
 to reduce them.
• Rotate 
DISTORTION
 until you hear
the amount of distortion you want.
• Press 
REVERB
 in on each chan-
nel where you want to apply
reverb effects. Then rotate
REVERB LEVEL 
toward 
MAX
 to
increase the amount of reverb, or
toward 
MIN
 to lower it.
4. To turn the MPS-50 off, press
POWER
 down.
USING HEADPHONES
To listen privately, connect low-imped-
ance headphones (available at your lo-
cal RadioShack store) with a 
1
/
4
-inch
(6.35 mm) phone plug to the 
PHONES
jack on the back of the MPS-50.
Listening Safely
To protect your hearing, follow these
guidelines when you use headphones.
• Set the volume to the lowest setting
before you begin listening. After you
begin listening, adjust the volume to
a comfortable level.
• Do not listen at extremely high vol-
ume levels. Extended high-volume
listening can lead to permanent
hearing loss.
• Once you set the volume, do not
increase it. Over time, your ears
adapt to the volume level, so a vol-
ume level that does not cause dis-
comfort might still damage your
hearing. 
MI MA OFF
MA
MIMI MA MI MA MI MA MI MA MI MA MI MA
ON OFF
ON OFF
GAIN
BASS
TREBLE REVERB
GAIN
BASS
TREBLE
HIGH LOW
REVERB
REVERB
LEVEL
DISTORTION MA
CHANNEL  1 CHANNEL  2
INPUT
HIGH LOW
INPUT
MI MA MI MA
GAIN
BASS
HIGH LOW
CHANNEL  1
INPUT
MI MA MI MA
GAIN
BASS
HIGH LOW
CHANNEL  2
INPUT
CA
UT
ION
RISK OF ELECTRIC 
DO NOT OPEN
GUITAR  AMPLIFIER
POWER  SUPPLY:  ~120V  60Hz  150W (FUSE 2A  
250V)
Custom  Manufactured  in  China
for  RadioShack ,  A  Division  of  Tandy
Corporation,  Fort  Worth,  TX  76102
CAT.  NO.  32-2046
MPS-50
R
115703
COMMERCIAL  AUDIO
EQUIPMENT
CAUTION TO  PREVENT  ELECTRIC  SHOCK  DO  NOT  USE  THIS  (POLARIZED)  PLUG  WITH  AN  EXTENSION  CORD  
RECEPTACLE
~120V AC 60Hz
150W
FUSE 2A 
250V
CAUTION DISCONNECT  SUPPLY  CORD  BEFORE  CHANGING  
CAUTION FOR  CONTINUED  PROTECTION  AGAINST  RISK  OF  FIRE  REPLACE  
ONLY
POWER
PHONES LINE
OUT
RETURN SEND REVERB
REMOTE
PHONES
32-2046.fm  Page 5  Monday, January 24, 2000  12:33 PM