What is Oversampling and why/why not its good?

I was hoping to get the answer as a part of discussion in my 'Diff in recording..." thread below, but did not quite get it.

How could you oversample faithfully already down graded form mastertape to 16/44.1 redbook CD signal? Is the oversampled signal best approximation that each CD player/DAC company comes up with? In other words is oversampling always good?

When CD player has specs like 20 bit or bit streaming what does it mean is been with the original redbook CD signal?

DSD i believe is high sampling rate to begin with so you don't 'loose' signal quality when played thru SACD player.

This paper has a good overview of the basics behind the CD Digital audio and various forms of DAC conversion and filtering/over sampling and quantization/dither techniques used.


Needless to say there are many competing methods for DAC conversion, however, each method when implemented correctly delivers a sound quality that is of extremely high quality. I find myself unable to hear differences between several different DAC methods...be it in my Digital Sound Processor pre amp or my various CD players.

DSD is a digital technique used in SACD....the technique is also used in a similar analog fashion by one bit DAC's for CD players. The idea is to use one bit for the data and sample at a very high rate. Like a light switch being turned on and off at very high speed to create the desired lighting level....the technique works but it does introduce high frequency noise outside the audible band that is filtered out by a low pass filter in the case of CD...or in the case of SACD it appears to be sent through your equipment (some people question the logic of putting high frequency noise above the audible band through your tweeter...some are concerned about the heat it may generate)
Best thing would be to call me at 563-528-0884 as your answer is long.

First off, over sampling is only part of what makes a difference and is not the most important part but to answer your question...

Oversampling is the CD players way of comparing multiple snap shots of the same frame of music and matching the best picture with the original.

If an engineer knows how to design a digital section, oversampling can be a bad thing as it pulls down the power supply and slows down the DAC's.

Bitstream is a constant flow of 1 bit at a time so it is technically a DAC with 255 times over sampling. Only advantage of this is that it can make cheap players sound better.

The advantages of SACD are more related to the fact that the recording proccess drops from 9 stages to 2 and the fact that it gets rid of the need for water marking or copy protection which hurts sound. Again, the main advantage is that it makes good sounding digital more affordable. A killer CD player sounds better than most SACD players.

Maybe others can do a better job than I of explaining things.

Thanks Shadorne and Duane. Let me read the link that Shadorne provided and digest what this all means.