Single box CD players with NO oversampling?

D/A convertors do not need to have oversampling to work, it's just that they are almost always implemented to smooth out the filter curve. A pure analog "Brick Wall" Filter can be used somewhere past 20,000 hz with no over sampling. This was done in some very early CD players from the early 1980's. However, this didn't work very well because it caused distortions and artifacts in the audiable bandwidth. To say that the "Basic sample rate... is 4x oversampling" is completely incorrect. I had a 2x oversampling CD player back in 1985. At that time 4x oversampling was a totally new thing. I'm sure a company like Audio Note has found a way to implement an analog filter without causing distortion in the audiable bands.

Actually, I believe Audio Note is depending on the speakers and the listener's ears to accomplish the ultrasonic filtering, letting one's amplification fend for itself with an unfiltered signal from the DAC.

Every Compact Disc player on the market use oversampling. See the "Compact Disc" logo on every compact disc player ? Do you think those logo was put on all cd player by accident ? They pay to have it there. They pay to have the formula to build and sell compact disc player. Think of the Intel Pentium CPU's. The new Intel CPU's are basically X86 code, made faster, for example XT, AT, 386, 486, Petium, II, III, IV etc... The basic instruction set has to be there, to be backward compatible with the old softwares. Back to the compact disc, the samething applied. Some company does better oversampling, some do worst, some just bought OEM parts from Sony or Philips then build their own power supply (tube or solid state). TEAC develope their own transport (Wadia) but still the basic oversampling is there plus more (Wadia use 32X, 64X etc...)
Let say you build a brand new CD player, and try to sell it on the market. Sony /Philips will sue you until you take it off the market. You cannot call it a "cd player", neither. Because it is copyright. The same apply for media, not the content but the "disc" itself, also copyright. That mean your new build "what ever it is that you build" cannot (not suppose to) read the standard Compact Disc. Like a "pure" SACD player, which might not need oversampling, Sony own the "SA"CD player"" so somebody need to pay for the copyright or pattern anyway to sell "SACD player and/or media" see the circling ?

I was an adult that own a cd player in 1985 :-)

Regards

Zaikesman. There have been hundreds if not thousands of Audio Note Dac's sold world wide. I have never heard of one person who had a problem because of what you have described. Many are not used with Audio Note amps. A Goldmund amplifier produces a bandwidth from dc. to over 2 mghz. Does that imply it can't be used with a speaker that has a frequency response of 20Hz-20kHz? What are you basing your opinions on? Are you familiar with the technology behind a Audio note DAC? Ever heard one? Eliminating a brickwall filter should not hurt any amplifier or speaker on the planet. You should do some research before making such claims.

Jc, Zikesman - If you read the Audio Note web site carefully (the section on DACs), it says clearly that no DIGITAL filtering is used. But if you look at the comparison tables, it does make mention of ANALOG filters. It just does not describe the characteristics of the analog filter. My difficulty in understanding all of this is as follows: no oversampling means 44.1 kHz, and that means aliasing components down to 22.05kHz. Filtering this out EFFECTIVELY implies a BRICK WALL filter. Audio Note claims some proprietary filtering. If it's not brick wall, then it doesn't filter out (effectively)the aliasing conponents that are JUST ABOVE the audio band.