JBL Bass2/Basswave Technical Manual - page 6
5
Powered Subwoofer
BASS2/BASSWAVE
Additional Service Notes/Revisions
Customers who complain of a low level distortion
heard only during very quiet musical passages, or
experience erratic/inconsistent turn-on performance
may need to have their units modified as follows:
1. Remove jumper wire JW12.
2. Change resistor R24 to a 22k ohm, 5%, 1/8W.
(JBL part# HM185-02202-00).
3. Change capacitor C19 to a .0047 uf cap.
(JBL part# 3679472120).
4. Cut trace at SW1 (middle pin which runs to JW12).
5. Add 2" insulated jumper wire from SW1 (middle
pin) to right-hand side of JW12. Route this jumper
away from the four large diodes.
6. Add an uninsulated jumper from the left-hand side
of JW12 to the ground trace which runs just to
the right of it.
Serial numbers below should already be modified.
100v
120v
230v
JSEKE10988
and above
JSEKD13486
and above
JSELD027239
and above
JSEKF20034
and above
JSELF020498
and above
Early versions of the units ending with serial #JSELD
024124 had a 18VDC output jack; later versions are
missing this. It's presence or absence does not affect
subwoofer operation in any way.
Early versions of the units below serial # JSELD
024125 will cycle into a standby mode when the
signal source is absent after a predetermined time;
the green LED turns OFF when this happens on the
120 volt version, the LED cycles to RED on the 230
volt versions. The unit's sensitivity to input signals
was increased on serial # JSELD 024125 and above;
these units may stay ON, even when the input signal
is absent. This is a normal condition, and does not
compromise the safety, integrity, or dependability of
the product in any way. The standby condition that
took place on earlier versions was an electronic
muting, and both versions draw the same amount of
power at all times, whether muted or ON.
NOTE: If a customer (of a later revision) is insistent
that the auto-mute feature work on his subwoofer, an
easy way to accomplish this is to use the speaker
level (high level) inputs on the unit in lieu of the RCA
jacks.
WIRING DIAGRAM