Merry Christmas 
The problem with MP3Gain is, it does not work via tags but modifies the file directly. The tags are only a backup information to be able to restore the original file. And it only works on MP3 files, as the name suggests.
I have a slightly different problem with my clip+ and replay gain. The replaygain values are listed correctly in both foobar2k and clip+, but there is no change in volume when switching between the off/song/album modes and the files with replay gain tags are clearly louder than files that had the replaygain applied to the data (lossy).
Before someone says it’s foobar’s fault, the replaygain values were done with the official encoder (1.2.1b) via the --replay-gain switch.
If the clip+ has problems reading those tags it simply means replay gain is not implemented correctly.
And what’s more interesting, i went and installed mediamonkey and scanned the same track with foobar, official and mediamonkey. My results:
The only difference between foobar replay gain tags and official tags is one additional tag namely REPLAYGAIN_REFERENCE_LOUDNESS, which is set to 89.0dB per default (and the fact i scanned in track mode while the official encoder scans in album mode). Everything else is the same.
All 3 files’ replay gain tracks are recognized by the clip+ correctly
All 3 files sound louder than my mp3 version of the same song (which has the track gain applied) in off/song/album mode
With all 3 files, there is no volume difference between off/song/album mode
My clip+ firmware is V01.01.05F (don’t know if it’s the newest, the updater doesn’t like me (click me) (win7 x64))
foobar:
official tags:
Now, let’s see how MM tags look like:
After comparing the tags, you can clearly see which program behaves incorrectly - MediaMonkey, not foobar.
Now let’s assume MediaMonkey’s replay gain tags do work and i’m an exception.
This means that to be able to use the whole potential of my player, i am forced to use a specific program. That was initially one of the reasons i decided against buying an apple product, but now i am being told there is no other way (at least atm) around it again - not good.
