Yamaha DVS 5750 (dvd)

[zumbo]

I set-up this dvd player for a friend yesterday. It has a feature called CD Upsampling. It states:
This feature allows you to convert your music CD to a higher sampling rate using sophisticated digital signal processing for better sound quality. If you have activated this upsampling, the player will automatically switch to stereo mode.
OFF
Select this to disable CD-upsampling.

88.2 kHz X2
Select this to convert the sampling rate of the CD's twice higher than the original.

176.4 kHz X4
Select this to convert the sampling rate of the CD's four times higher than the original.

Note:
This setting is only applicable for the signals output from the analog jacks.

This player was $152.99. I didn't get a chance to try it out, so I don't know if it makes a big difference.

My Yamaha S840 retails for $399.99, and it doesn't have this feature.

Does anyone know if this is a good feature, and if it really makes a difference?

 

[MDS]

You'll have to listen to see if you can really tell a difference, but generally it wil not improve things much, if at all. Upsampling involves adding more samples than exist in the recording. Given that the upsampling rates of that player are exact multiples of 44.1 kHz (CD sampling rate), the algorithm is simple - double every sample for 88.2 and quadruple each sample for 176.4.

What it does buy you is the fact that the job of the reconstruction filter is now simpler (this is part of the digital to analog conversion). The filter chops that frequency in half (search for 'Nyquist' for threads on the topic) and any noise or reduction in the signal that results from that process will be well above our range of hearing - theoretically making the audio more accurate in the frequency range we can hear.