Jeff Rowland Design Group 501 - Manual (Page 16)

© J e f f R ow l a n d d e s i g n g R o u p 2 0 07. a l l R i g h t s R e s e R v e d .
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OW N E R ’ S M A N UA L M O D E L 5 01 M O N O A M P L I FI E R
O P T I O N A L A d j u s T m e N T s
RISK OF ELECTRICAL SHOCK!
WARNING: The instructions in this section are meant for qualified JRDG service
per sonnel only; however, if you as an end user choose to attempt these adjustments
yourself, JRDG cannot be held liable for any damage that may occur to your Model 501
Mono Amplifier because of your actions. Further, accessing the interior of your Model
501 by removing the bottom cover can expose you to dangerous, potentially lethal
electrical voltages. Thus, JRDG cannot be held liable for any injury you may sustain
should you undertake any of these adjustments yourself.
ADjUSTING AMPLIFIER OVERALL GAIN
STEP 1: Unplug the Model 501 Mono Amplifier power cable
from the wall AC outlet.
STEP 2: Place the unit upside-down on a soft, clean surface.
Using a #2 Phillips screwdriver, remove the ten screws that
secure the bottom cover of the unit.
STEP 3: Locate jumper J103 on the rear panel board of the unit.
Using needle-nose pliers, move the jumper from between pins
2 and 3 to pins 1 and 2. (See FIGURES 1 and 2). Overall amplifier
gain increases to 32 dB.
STEP 4: Reinstall the bottom cover and replace the ten screws
to secure it to the chassis.
FIGURE 1: Location of Jumper J103 on the inside back
panel of the Model 501
j103
(DEFAULT) 26 dB GAIN
j103
(ALTERNATE) 32 dB GAIN
jUMPERS
FIGURE 2: Close-up of J103
settings for the Model 501
1 2 3
1 2 3