Worlds best DAC

Other than the non oversampling school such as Zanden, check out the Orpheus Heritage, built by Anagram Technologies, uses their most advanced chip sets which are not available to any other manufacturers.
Unfortunately no digital will ever sound any good until they dispense with the sine x/x assumption in the maths, which creates truncation errors on every calculation. There may be some professional DAC's on the planet that do this, but the issue becomes a licensing nightmare as one could argue that it ceases to be red book CD.
With regard to the Orpheus I note that the designer dispenses with the incoming master clock signal. Instead, the ultra-advanced algorithms inside the Heritage derive a new clock signal from the transport's incoming data
stream.
I have access to a DAC which does the same, it recreates the clock from the data stream and uses non sine x/x calculations along with several other tweaks and it is significantly less grainy than anything commercially available.
I have heard the Meitner/Emm Labs - quite good, sort of musical, great depth, lowish level of grain and DCS - let's just say not my cup of tea.
The oversampling reduces the sine x/x errors.

And further to the above, the other digital system which I can listen to uses a power amp similar in architecture to the Devialet D-Premier which is supposedly the first product to feature a new form of amplification called ADH® (Analogue/Digital Hybrid), specially developed by Devialet.
The amplifier I listen to which predates the Devialet by some years, has an analogue input, digital switching output stage wherein proprietary algorithms reverse out the sine x/x truncations errors as well as any other measureable system errors upstream. It switches at less than a trillionth of a second.
This technology seems to redefine what is possible with digital. Unfortunately for most of us our analogue systems are of a different construct ( yes I still prefer analogue ).