SACD vs. Blu-Ray for audio quality/sonics

Thank you for response and insight.  Jim

willemj - I agree with #1

re #2 - IIRC, they selected only studies for meta-analysis where the redbook layer of an SACD was used.

In general, it seems wise for a consumer to choose SACDs as the mastering/recording will usually be done well and not "mastered for itunes) or some such.

Finally, I thought the major effect of using high sample rates was that you could avoid brickwall filters

AudiogoN members continue to be much of a light for knowledge.  Thanks, Jim

Some history from Philips research: https://www.philips.com/a-w/research/technologies/cd/technology.html

@rAndy-11 

Yes avoiding brickwall filters helps with passband ripple - this has been the long standing argument for upsampling. However randomization of DAC non-linearity is not well understood. Basically the higher frequency noise in high sample rates act like another form of dither that remove the quantization level errors of the DAC itself. 

Of course, the latest chips use other techniques too. The ESS chip in the Benchmark DAC 3 randomly selects which 1 bit sigma delta is used to convert (128 to choose from). This randomizes non-linearity. This is why I believe the latest devices sound like the best analog and why many like DSD or upsampling. or high sample rate files over redbook. The jitter monster was slayed about 15 years ago but only recently have designs addressed the inherent non-linearities of the levels in the DAC itself.