Biamp CPA130 - Manual (Page 11)

INTERNAL MODIFICATIONS
NOTE: Modifications must be performed by qualified service professionals. Disconnect the CPA130 from the AC outlet. Remove the top
panel to access internal modifications. The diagram below shows the printed circuit board (PCB) and components as they appear on each
amplifier channel module.
IN
OUT
FILTER
High-Pass Filter: This two-position jumper strap enables or disables a 18dB/octave 180Hz High-Pass Filter for that channel of the
amplifier. When the strap is in the "IN" (up) position, the High-Pass Filter is enabled. When the strap is in the "OUT" (down) position, the
High-Pass Filter is disabled. The High-Pass Filters must be enabled whenever the CPA130 is used for driving distributed speaker
systems. This eliminates excessive current at low frequencies due to speaker transformer inductance, which can cause distortion or
damage to the amplifier. If the CPA130 is used in mono-bridge mode to drive a distributed speaker system, it is only necessary for the
Channel 1 High-Pass Filter to be enabled. The CPA130 is shipped from the factory with the High-Pass Filters disabled ("OUT").
Front Panel Level Controls: The Channel Level Controls may be moved to the front panel of the CPA130. Remove the plugs from the
front panel mounting holes (save them for the rear panel mounting holes). Remove the knobs from the level controls. Remove the nuts
from the level controls using a 11mm (7/16") nut driver. Move the level controls to the front panel mounting holes (make sure that Channel
1 and Channel 2 level controls are in their proper locations). Re-install nuts and knobs (hold onto controls to avoid twisting wires). Install
plugs in rear panel mounting holes. Check wire routing to avoid pinching or over-heating of wires.
9