Sansa Clip Pitch Issue
Personal observation, as well as reports of other users, indicate that music files played on the Sansa Clip exhibit lower pitch, and thus longer duration, than expected. However, SanDisk technical support have stated as late as 2009/09/17 that this problem was fixed by firmware release 02.01.32. I tested SanDisk’s assertion by playing the same files on two Sansa Clips with the latest firmware version, as well as on two other MP3 players (an Apple iPod and a Philips GoGear).
The tests show that Sansa Clip with the latest firmware update continues to exhibit the pitch/duration error. The duration of an MP3 file sampled at 44.1kHz and played on a Sansa Clip was found to be >1% greater than the original, corresponding to a pitch lower by 19–20 cents than expected. By contrast, the other players exhibited pitch variations of < 4 cents (Philips) and < 1 cent (Apple), that is, below the threshold of human perception (5 cents).
The assertion of SanDisk technical support was thus found to be false.
However, the Clip’s pitch error is close to, but below, what might be regarded as the average pitch recognition value (25 cents). Hence, casual listeners, or those without musical training and/or without good pitch discrimination, are unlikely to be seriously affected by this issue. By contrast, serious listeners or those with musical training and/or good pitch discrimination will probably find the Sansa Clip (as well as other SanDisk products which exhibit this problem) highly unsatisfactory.
Personal observation, as well as reports of other Sansa Clip users, indicate that music files played on this MP3 player are off-pitch . For instance, DAVEK reported an error of -19.5 cents at 1000Hz on a file sampled at 44.1kHz on his Sansa Clip 8GB .
On the other hand, SanDisk technical support have stated that this problem was fixed by the latest firmware release (version 02.01.32 of February 2009) . To test this assertion, I played the same audio file on two different Sansa Clips, on two other MP3 players, and on iTunes/PowerMac G4, and compared the results.
I used the following MP3 players:
Philips GoGear SA2115/37, f/w v4.16
Apple iPod Classic 80G, v1.1.2 PC
Sansa Clip 2GB, f/w V02.01.32A
Sansa Clip 1GB, f/w V02.01.32A
Additionally, I also tested iTunes running on a PowerMac G4 under Mac OS X v10.3.9.
I created a source file by ripping a track from an audio CD to AIFF, 16bits, 44.1kHz, stereo . I edited the source with Sound Studio to insert two 1-second long 440Hz sine tones, exactly 360 seconds apart. Then I encoded the source to MP3 in 2 versions; version 1 with iTunes, 128k; version 2 with LAME v3.90.3, VBR (alt-preset-extreme).
I copied the 2 MP3 files (128k and VBR) to the MP3 players from a PC in the usual manner .
I connected in turn each player’s headphone port to a Toshiba Satellite’s analogue audio-in port and recorded the player’s output with Audacity. I saved the result in Audacity’s format (AUP), and also exported it to WAV.
For each player, I measured in the WAV file the interval between the two 440Hz tones (which was exactly 360s in the source file).
The results are listed below as xxx/yyy (zzz), where xxx is the interval for the 128k file in seconds, yyy for the VBR file, and zzz the percentage relative to 360, rounded to 2 decimals.
Note that only the GoGear generated different values for the two files.
Philips GoGear … 360.528/359.361 (100.15/99.82)
iPod Classic … 359.854/359.854 (99.96)
iTunes … 360.002/360.002 (100)
Sansa Clip 2GB … 364.084/364.084 (101.13)
Sansa Clip 1GB … 364.085/364.085 (101.13)
In terms of pitch, these different intervals translate empirically  as follows (in absolute values):
Philips GoGear … < 3 cents / < 4 cents
iPod Classic … < 1 cent
iTunes … << 1 cent
Sansa Clip 2GB … 19 cents – 20 cents
Sansa Clip 1GB … 19 cents – 20 cents
(1) The duration of 44.1kHz MP3 files played on the Sansa Clip is greater by >1% relative to the source, which is considerably higher than the variation exhibited by either the Philips GoGear or the iPod.
(2) This deviation corresponds to a pitch error of between 19 and 20 cents, which is an excellent match to the value reported by DAVEK .
(3) According to data quoted in Wikipedia, 5 cents can be taken as the threshold of human pitch perception, and most normal adults can “very reliably” recognise pitch differences of 25 cents or more . The Sansa Clip’s pitch error is close to, but below the latter value. This would suggest that many users – in particular, casual listeners, those without musical training, or those with average and below average pitch discrimination – would be little affected by this issue. On the other hand, dedicated listeners or users with musical training and/or above average pitch discrimination would indeed perceive this issue as a problem.
(4) The fact that this kind of bug was allowed to occur in the final product would suggest that the Clip development team did not include anyone musically trained or with good pitch recognition. This would further suggest that the Clip (as well as other SanDisk products which exhibit this error) is not intended for customers with discriminating ears.
(5) According to SanDisk technical support,
“There is an available firmware update for your Sansa Clip. This should fix the issue with the pitch.” 
This assertion is clearly in flagrant contradiction with the facts; moreover, it is also in contradiction with statements of other representatives of SanDisk, eg,
“The SanDisk Firmware developers are aware of this issue and a fix is in the works for the Sansa Fuze and the Sansa Clip+. At this time due to development targeted on the Clip+, firmware for the original Clip is not currently under development. This may change in the future as time permits.” 
These contradictions raise doubts regarding either the expertise or the veracity of SanDisk technical support – or perhaps both.
I can make available the files used to anyone who desires, provided a suitable arrangement can be made. The whole project is 2.19GB, of which the test files are 0.086GB, the recordings in WAV format 0.72GB, and the same in AUP format 1.41GB.
 See <http://en.wikipedia.org/wiki/Sansa_Clip#Music_Pitch_Bug>, retrieved 2009/09/19.
 See <http://forums.sandisk.com/sansa/board/message?board.id=sansafuse&message.id=18012#M18012>, retrieved 2009/09/19.
 SanDisk Technical Support, personal communication, 2009/09/17.
 Specifically, Angela Hewitt’s “Bach: The Well-Tempered Clavier”, Hyperion CDA67741/4 (2009), CD 2, Track 24, BWV 869: Fugue.
 Sansa Clip 1GB was connected in MSC mode, the other in MTP mode.
 That is, using Peak to change the pitch of the measured interval until its duration was close enough to 360s.
 See <http://en.wikipedia.org/wiki/Cent_(music)>, retrieved 2009/09/19.
 See <http://forums.sandisk.com/sansa/board/message?board.id=sansafuse&view=by_date_ascending&message.id=32947#M32947>, retrieved 2009/09/19.
[Last modified: 2009/09/20]