We don't sell many CP-135 / CP-136 for new Audio Panel installations, nor do we recommend them for this application. But if you need a slide-in replacement, a CP-135 and/or CP-136 may be worth considering. (It is disproportionately expensive to install an Audio Panel because of all the wires that come together.)
The CP-135 and CP-136 are physically interchangeable.
The difference between the CP-135 and CP-136 is an Audio Amplifier. The CP-136 is able to power a cabin speaker, and the CP-135 is not.
If a CP-135 is replaced with a CP-136, the installation will not utilize the CP-136's amplifier as wired, and the speaker will not be powered. (It would require some additional connections to use the amplifier.)
If a CP-136 is replaced with a CP-135, the cabin speaker will no longer be powered.
For either the CP-135 or CP-136, the "M" suffix means Marker Beacon Receiver. The CP-135M and CP-136M have an internal Marker Beacon Receiver. The CP-135 and CP-136 are able to use an external Marker Beacon Receiver, but they do not have this receiver built in.
The CP-136M is an Audio Panel with Marker Beacon Receiver. This receiver is built in, unlike the CP-136.
The CP-136M is a basic Audio Panel that offers Marker Beacon lights and Mute, self-test function, and pushbutton operation.
An interesting feature of the CP-136M is the ability to monitor more than one audio source. For example, if you push the BOTH button, you can monitor both COMM transceivers at the same time. You may also listen to more than one NAV source at once.
The CP-136M has the following switch positions:
- 2 COMMs
- Both COMMs
- 2 NAVs
- Marker Beacon / DME