Link
10. Why doesn't the equalizer work in the CD audio and MIDI plug-ins?
Winamp plays these formats "passively", meaning the actual sound data never goes through Winamp. In the case of CD audio, it goes from your CD-ROM to your sound card through a cable inside your computer, and in the case of MIDI, your sound card actually synthesizes the sound from MIDI events recorded in the file. Either way, it's out of Winamp's reach, so to speak.
If you still want to use the EQ with your CDs, there is a special Plugin for that. Download Copah's CD-Reader and install it. Make sure your Winamp isn't running and goto your Winamp directory and rename the "in_cdda.dll" to "in_cdda.old". Perhaps you have to configure the Plugin by going to Preferences - Plugins/input select CD-Reader and click "configure". Make sure the correct drives are selected.
Some older CD-ROM-Drives don't support this plugin!
Winamp will do this job automatically in Version 3. The Betas are already availeble here.