Very slight noise is added to the sample every time I save the soundfont.

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  Message de musicbugfix le …
  Very slight noise is added to the sample every time I save the soundfont.
  (version: polyphone 2.5.1)
  
  Suppose you do "wav export" for one sample(for example, 400Hz sine wave), then apply some changes to the soundfont(anything but should not affect the sample itself. ex. add new preset) and save the soundfont. Close and open the soundfont and do "wav export" for the same sample you exported.
  The two exported wav should be identical, but it's not. It shows difference if you compared by foobar bit compare tool(See the picture).
  To see what type of noise was added, I imported them to Audacity, applied phase inversion to one sample, and mixed down them to one track. This will cancel the identical sound and show the difference between them. It seemed that pulse like very small noises were added. 
  (the last track shows the noise around - 90db)
  This noise itself is not so problematic, because it is not audible. The problem is that it is accumulated every time I save the soundfont.
  (The former: saved one time
  The latter: saved several times
  noise level was increased to -80 db)
  
  I am afraid that this finally could affect the soundfont quality.  
  I have no idea why this kind of phenomena is happened. Is there very weak limiter or something???
• Message de musicbugfix le …
  Let me add one more picture to show that the noise is actually pulse like.
  And If the soundfont is in 24 bit, the noise is not pulse like but like white noise.
  This is also problematic. This noise is too big for 24 bit, as the weak signal of 24 bit masked with the noise, and it will work as if 16 bit.
• Message de musicbugfix le …
  Just in case, original sine wave file used.
  It's in flac file but 100% identical to the original wav file.
  400 24bit -1db.flac

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