First you need root. It's important because CallRecorder needs root access to record the call through the phone's kernel.
From the feedbacks it seems to work on rooted stock and OptimusDAY.
How to use: Install CallRecorder (This is just a trial version, the full version is a paid app and available on Google Play)
Open it and go to Settings-> Recording-> Recording method-> Set it to KERNEL
Under that set the audio format to AMR for kernel recording.
You can set the other filter and options to whatever you want.
Both sides are recorded with average quality and all the same volume
You can't playback the recorded conversation with the program's built-in music player. You can play it with VLC for Android Beta.
Edit: Here's the solution to play the recorded call with the CallRecorded's built-in player:
Go to Setting-> Audio Player and tick Android decoder for AMR.
Please give me feedbacks. You can freely translate it for example to Spanish, so you can share it on HTCMania, but please state McKangi and colonell as sources.
Edited by Ducsidu, 20 August 2013 - 09:04 AM.