I think I have worked out and solved my distortion problems with 2.0b3 and 2.0b7

I was very puzzled that other people had no problems with the MP3 file I posted, so I looked into what was happening a little more. I had already checked that my loudness was at 0dB and that I had my volume set at under 0dB.

I never use the equaliser, so I hadn't though to look in there. When I had a look at the equaliser settings I had a shock. Instead of the first bank of (flat) settings being selected the second bank was selected and they weren't flat. The left channel was flat, but the right channel had seven of the ten bands set to minimum (none of the bands were boosted at all). I changed the equaliser to use the first (flat) bank of settings instead and tried one of my test tracks, sure enough the distortion had gone.

The unit clearly wasn't using the eq settings that the interface showed it as using, I WOULD have noticed if the right channel had it's output pulled down that much. I have since gone back and selected the second set of settings again and it sounds as it should, with the right channel very obviously attenuated across much of the frequency range.

So, it looks like what probably happened is that as part of the 1.03 - 2.0b3 upgrade process (or sometime after that) the eq settings got corrupted in some way that was causing the player to boost the output signal beyond 0dB, thus causing clipping on some tracks.

Also the corruption was not causing 1.03 a problem, when I downgraded to 1.03 the problem went away, until I went back to 2.0b3 or 2.0b7

So if anyone has unexpected problems with clipping then go check your equaliser and switch to another (flat) bank of settings just in case you don't have the settings you think you have...

Hmmm

This might not be the full explanation after all. I have just checked my Mk1 (running 2.0b3) and it has clipping problems as well, but doesn't appear to have any strange equaliser settings.

I realise that the fact that I am seeing the problem with both my Mk1 and Mk2a (and that other people are not seeing the problem) points to a problem with my setup, so I shall have to go and investigate what else in my setup could be causing the problems.

Very confusing...

Well, it has taken a while but I think I have finally tracked down all my clipping issues, it has been a real struggle because it turned out I had several different sources of clipping. They were:

• Very, very obvious and nasty clipping on my main test track (Don't Panic from the Coldplay album) from the very start of the track. This only effected my Mk2a and looks like it was due to the corrupted eq settings as I documented earlier.
  
• Subtle, but irritating clipping throughout my main test track. It turns out that my CD-ROM in my main desktop machine has a secret dislike for the Coldplay album, resulting in small amount of clipping when ripping it. The CDROM in my server doesn't have this problem and even though AudioGrabber was generating the same checksums using the two different drives there were differences in the WAV files.
  
• Even more subtle clipping from 36 seconds into the track, to the end. This one took a while to track down (though it was clear early on it was nothing to do with my empegs). Somehow a little known feature (to me) on my SoundBlaster AWE64 had got turned on. The feature is called "3D Stereo Enhancement" and it would appear with some tracks, including my test track, it can cause subtle clipping of the output...
  

So I have had a fun couple of days...

In reply to:

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The feature is called "3D Stereo Enhancement" and it would appear...

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I'm a bit confused about your comment here. How have you been ripping these tracks? As I understand it your ripped data shouldn't go anywhere near your soundcard and therefore shouldn't have been affected by this setting.

This "feature" caused a problem because for most of the testing I was playing my empegs through my PC, with the empeg plugged into the line-in on the sound card (I was doing this because my wife got fed up with me testing on the hifi in the living room).

One would assume (at least I did) that the signal from the line-in was passed straight through to the output stage on the sound card. Because of this assumption when I heard clipping on both the empeg and WinAmp I was assuming it had to be a further problem with the ripping process. I later discovered that the "3D Stereo Enhancement" "feature" was turned on and that, to my surprise, it affected the signal coming from line-in as well. Because of this it looked for a while like I had an identical ripping problem with two different CD drives, which while it sounded unlikely, was the best explanation I had until I found the hidden "feature".

Ah right I'm with you now. Sorry about that. I thought it had somehow corrupted your ripped data .

That's alright, it has been a very confusing couple of days tracking this down. I have been half way through typing up my explanation here several times before going "doh, that can't be the complete reason because..."