Clipping/distortion during playback

[galiyosha]

Hello. I'm experiencing some clipping/distortion that's not present in the original file and does not occur when playing back the same file through the stock firmware. Sansa Clip+ running Rockbox 3.7.1. Tried with r29113 as well with the same result. Every audio processing option (EQ, compressor, ReplayGain, dithering) was disabled in both firmwares (hope I haven't missed any). Volume was set to -15 in Rockbox and I've tried to match it in the stock firmware (it came out 0,5 dB louder).

stock firmware
Rockbox
original file

There are several clicks and pops in the Rockbox recording throughout, but the issue is most prominent from 0:32 on. After every hit of the kick drum, there's an evident click/pop that's not there in the other two.

This does not seem to be an issue with the MP3 decoder. When I decoded the file on a computer (mad 0.15.2b) and uploaded it to the device as a wave file, the clipping/distortion was in fact even more pronounced in Rockbox while the playback was still fine on both a computer and the stock firmware.

I have no idea if this issue is hardware specific as the Clip+ is the only Rockbox-able player I have access to.

Sorry if this has been reported before but I couldn't find an applicable issue in the bug tracker. Thanks in advance for any suggestions.

[Buschel]

Our bug tracker has a similar report (http://www.rockbox.org/tracker/task/11851). I have added a link to this thread to collect the information in the bug tracker.
A new information from you is that this also happens when the files are decoded outside of rockbox and played back uncompressed (wav) on the clip+. To me this sounds like a codec configuration issue -- just a guess though.

Edit: I can hear this very well on your files. I could not hear it the files we had before. And it seems I need to correct myself -> this does not sound like clipping.

[thepiper92]

I have noticed this issue with a sort of clipping noise as well. It seems to occur in the left channel. I use Klipsch S4 headphones, so they are not exactly the headphones that come with the Clip+. I have tried other good headphones too, and the same result. Its this noise that is stopping me from using rockbox currently.