I just upgraded from 0.83, as there were a few components I wanted to try out that were only for 0.9 or higher. Unfortunately, after uninstalling the old version and installing the new one, songs that had previously been crystal clear now end up sounding kinda crackly at the peaks. I tested the files in winamp (resource hog that it is) and they sounded fine. I've tried turning replaygain off/on, output format is 16 bit, have tried using both 'primary sound driver' and the specific driver 'SoundMAX digital audio'... I've run out of ideas. Any thoughts? Thanks!

Make sure that files have RG info, in Preferences/Playback set Processing to "apply gain and prevent clipping according to peak", eventually add Advanced Limiter at the end of DSP queue, and maybe decrease Windows volume and mute all inputs/outputs you don't use.

That helped a little but there is still some very noticeable clipping, especially on the on the songs using more of the higher range (like classical).

You say you are running a 0.9 release. What version? What version of Windows?

What kind of files are you playing when you notice the problem? Is it always the same kind or different kinds?

What kind of "SoundMAX" sound card do you have, and what version of the drivers?

Are you sure you have disabled all DSP plugins or sound processing (except possibly the Advanced Limiter) in both foobar2000 and in your sound card software?

What third-party components are you using (any and all that were not included with foobar2000)?

Have you changed any preferences other than those releated to formatting from their defaults? [This especially applies to any DSPs such as the EQ, or the ReplayGain configuraiton in Preferences.]

Are you able to reproduce this crackling problem using a clean installation of the latest version (0.9.2b3 at the time of this writing) without third-party components?

Providing enough information for others to reproduce your problem is essential to finding a solution.