Your files show identical behaviour in both conditions.
I've tried the same thing with my clip+, stock firmware (V01.02.15A), and I get a clear difference (using my own silent files). I tried 16-bit digital silence, 16-bit dithered silence, and 16-bit noise-shaped dithered silence, all generated in Cool Edit Pro from 32-bit silence![wink.gif]()
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I don't have a Y splitter, so could only listen via earphones or connect directly to the PC - hence the direct connection to the PC is not a proper test of the Clip+'s performance when feeding earphones.
Through earphones at full volume (an impossibly loud volume setting for listening to full-scale waveforms without destroying your ears) I can hear that the noise level from a silent (all zeros, no dither) file drops dramatically when I press pause. With pause pressed, the output is essentially silent, whereas when playing silence it is not. Putting a fixed DC offset in the file vs all zeros, or a very slow ramp - no difference - same level of hiss playing all three. I could not hear any difference between dithered and undithered. I can hear the attenuator in the Clip+ acting rapidly when pause is pressed, especially when pausing the DC offset - it's not a hard click - it's a buzz caused by the attenuator stepping rapidly through a few discrete settings (about 12), which gives a stepped wave on the output.
Recording into my PC, the 0dB FS signal replayed at full volume on the Clip+ registered -10.3dB via my audiophile 2496 hence I am not using its full resolution.
Recording at 24-bits, you can see (and hear, if you crank the volume or digitally boost the signal) the change in noise level when pause is pressed. The recording of the paused state is not quite so silent as through earphones, but it is equally as silent as recording with the device switched off and/or disconnected, so I think this is the limit of my 24-bit sound card. You cannot see or hear any difference between dithered and undithered source but a third "silent" file with just noise-shaped dithering has the noise-shaped high frequency part easily visible on the recording (though within the audible range it looks and sounds the same, so all benefit of noise shaping is lost).
Recording at 16-bits (actually at 24-bits and converting, so I could control the conversion), the paused parts are still audibly and measurably less noisy than the playing-silence parts, but the difference is less pronounced than with the 24-bit recording. With dithered conversion, the difference is detectable but small.
Occasionally, especially when activated near the end of a file, the pause function is not silent at all, but is just as noisy as when "paying" - this seems to be a little (usually inaudible) "bug" which is worth watching out for.
It seems my sound card, even with more than 1-bit of headroom lost due to too low a level, is more than sufficient to capture the noise performance of the Sansa clip+ when its playing, but 16-bits is insufficient to capture quite how silent it is when paused. 24-bits on this sound card may be sufficient, but it's impossible to make that call without doing the test properly (Y splitter, correct levels somehow?).
Hope this helps.
Cheers,
David.
P.S. a test for another day would be a -90dB and then -100dB sinewave with noise shaped dither.
I've tried the same thing with my clip+, stock firmware (V01.02.15A), and I get a clear difference (using my own silent files). I tried 16-bit digital silence, 16-bit dithered silence, and 16-bit noise-shaped dithered silence, all generated in Cool Edit Pro from 32-bit silence
.I don't have a Y splitter, so could only listen via earphones or connect directly to the PC - hence the direct connection to the PC is not a proper test of the Clip+'s performance when feeding earphones.
Through earphones at full volume (an impossibly loud volume setting for listening to full-scale waveforms without destroying your ears) I can hear that the noise level from a silent (all zeros, no dither) file drops dramatically when I press pause. With pause pressed, the output is essentially silent, whereas when playing silence it is not. Putting a fixed DC offset in the file vs all zeros, or a very slow ramp - no difference - same level of hiss playing all three. I could not hear any difference between dithered and undithered. I can hear the attenuator in the Clip+ acting rapidly when pause is pressed, especially when pausing the DC offset - it's not a hard click - it's a buzz caused by the attenuator stepping rapidly through a few discrete settings (about 12), which gives a stepped wave on the output.
Recording into my PC, the 0dB FS signal replayed at full volume on the Clip+ registered -10.3dB via my audiophile 2496 hence I am not using its full resolution.
Recording at 24-bits, you can see (and hear, if you crank the volume or digitally boost the signal) the change in noise level when pause is pressed. The recording of the paused state is not quite so silent as through earphones, but it is equally as silent as recording with the device switched off and/or disconnected, so I think this is the limit of my 24-bit sound card. You cannot see or hear any difference between dithered and undithered source but a third "silent" file with just noise-shaped dithering has the noise-shaped high frequency part easily visible on the recording (though within the audible range it looks and sounds the same, so all benefit of noise shaping is lost).
Recording at 16-bits (actually at 24-bits and converting, so I could control the conversion), the paused parts are still audibly and measurably less noisy than the playing-silence parts, but the difference is less pronounced than with the 24-bit recording. With dithered conversion, the difference is detectable but small.
Occasionally, especially when activated near the end of a file, the pause function is not silent at all, but is just as noisy as when "paying" - this seems to be a little (usually inaudible) "bug" which is worth watching out for.
It seems my sound card, even with more than 1-bit of headroom lost due to too low a level, is more than sufficient to capture the noise performance of the Sansa clip+ when its playing, but 16-bits is insufficient to capture quite how silent it is when paused. 24-bits on this sound card may be sufficient, but it's impossible to make that call without doing the test properly (Y splitter, correct levels somehow?).
Hope this helps.
Cheers,
David.
P.S. a test for another day would be a -90dB and then -100dB sinewave with noise shaped dither.