Circuit Modifications; Changing The Model 300'S Operating Levels - Aphex COMPELLOR 300 Operating Manual

8.0 CIRCUIT MODIFICATIONS
This section contains several circuit modifications that have been imple-
mented in the field for custom applications. Modifications include:
• Changing the Model 300's Operating Levels
• Increasing the Model 300's Leveling Speed
• Unlinking the Model 300 for 2-channel Operation
• Modifying the COMPELLOR (all models) for Input Grounding
• Defeating the COMPELLOR (all models) Peak Limiter
Take a moment to read through each section to evaluate whether any one or
more modifications are applicable to your own installation. With a little
planning, all work can be completed during a single disassembly session.
8.1 Changing the Model 300's Operating Levels
Although the Model 300 is set at the factory for +4 dBm operating level, you
can set the COMPELLOR for three other reference levels (- 10, 0, or +8 dBm)
with the following procedure:
1. Remove the cover, knobs, and faceplate, as shown in Fig. 8-1 ( next page).
2. Loosen pot shaft nuts on the Display Boards.
3. Remove the ( 2) 8-32 Phillips screws on the front of the board(s).
4. Remove the 16-pin jumper and disconnect the red molex power harness.
5. Move the Display Control Boards to an upright position.
6. Locate the INPUT LEVEL level set dip on each Audio Processing Board,
as shown in Fig. 8-2 (on page 8-3).
7. Using a tweezer or other appropriate instrument, pull out the jumper
from the dip socket, and insert it into a desired level setting. Be sure to
observe the legends on side of socket.
8. Locate the OUPUT LEVEL level set on Audio Processing Board ( see Fig.
8-2), and repeat the process used in step 7 above.
9. Replace all board assemblies, install lower mounting screws.
10. Lower the top boards, carefully inserting the pot shaft into the support
bracket with nuts and washers on the outside.
11. Making sure the bushings are fully seated in the bracket, carefully
tighten the pot nuts. Applying too much torque will break a pot!
12. Replace the upper 8-32 mounting screws (with plastic washers).
13. Reconnect the power harness to the Audio Boards.
14. Insert the DIP jumper firmly into the Display Boards.
Circuit Modifications 8-1