⑤LEVEL
 This controls output level of effected 
signal. Typically output levels of both 
normal signal and effected signal 
should be adjusted to equal levels. 
⑥BOOST/NORMAL 
 Switch for BOOST/NORMAL. In BOOST 
mode, it provides tube sound in which 
mid-range is boosted by 3 dB.
 In NORMAL mode, classical tube sound 
is available.
⑦FOOTSWITCH
 Switch for effect/bypass. Stepping on this 
switch alternately turns effects on and off.  
 * Effect turns on when you depress the 
switch and effect turns off when you 
depress and release the switch. 
⑧LED INDICATOR
 This indicates the effect/bypass  status 
and battery condition. It lights when plug 
is inserted to input jack and effect is on. 
No LED light indicates the battery is low 
 or not installed.  In this case replace 
the battery.  
⑨DC IN (power input jack) 
 Jack for connection of external 
power supply to effect.  Be sure to 
use the correct Maxon AC adaptor.
 For further information on AC adaptor, 
refer to page 26. 
    Turn down amplifier’s volume 
   to the minimum before con-
necting AC adaptor or DC plug. 
⑩OPERATING VOLTAGE SWITCH
 Slide it to left side for 18V (±9V) 
and right side for 9V (±4.5V).
     Turn down amplifier’s volume 
  to the minimum before sliding 
this switch. 
⑪INTERNAL LED INDICATOR
 This indicates the status of operat-
ing voltage.  It lights at 9V (±4.5V). 
No LED light indicates the operat-
ing voltage is 18V (±9V). 
 ment.  OD9Pro+ can also be used at 9 volts (plus and minus 4.5 volts).  Stable 
sound is constantly available regardless of selected voltage. 
●True Bypass Switching using 4PDT switch lets your instrument’s signal pass 
through a non-electronic bypass line when the effect is disengaged, feeding your 
amp with direct, unaltered signal from your instrument. 
●Easy-access, no tools battery compartment. 
OD9Pro+