Thanks Bruno for the explanation and design "input" - you made me laugh with the link to your 2 "design paths". I would say that my approach really is both - because my design goals are often aimed at perfection (No. 2), when I realize it can't and/or is difficult to do, I revert to the first one and then juggle between them ...
I have also found that my ways of designing often transgress "normal" engineering approaches which makes specifying goals in words or specs somewhat elusive ... E.g. I have mounted some of my amplifier designs on balsawood, thereby eliminating the PCB, something that, as I perceive it, caused the design to sound more open, liquid, and less "noisy" (smile).
However, my reason for researching this as a collaborative DIY- project is that I have not found a commercially available solution that satisfies my wishes.
I know that grimmaudio has the AD1 available which appears interesting and seems to be a very special design (although too expensive for my budget and not entirely convenient for me - I'm looking for something portable). Also, now the KORG MR-1000 with a 5,6 MHz DSD sampling rate is in the market - although maybe in its base design it is not in the same league as the AD1.
There are other designs as well but I've never heard of a 256*fs design. Can you share who/which company makes this?
BUT - even more important - my intuition keeps telling me that the high-frequency output power of delta-sigma modulator designs (mostly at 64*fs) will have an (negative) effect on me, personally (BTW there is a study indicating that although a person may not actually hear a sound/tone e.g. above 20 kHz, brain wave measurements indicate that the brain waves change when the tone is present). I reckon this noise will also influence electronics and speakers.
I consider my intuition to be correct in this respect which is why I'm looking for ways of overcoming this - e.g. by designing a delta-sigma at 256*fs, or, if possible, at an even higher fs, and as a low-order design. I know that very high frequency delta-sigma modulators have been made, yet my technical know-how does not allow me to discern if they are applicable to high-end audio.
An alternative is a very high sample frequency 20-24 bit PCM converter, e.g. ~ 400 kHz fs (I have my reasons for this, should be possible to disable any digital filters), but I haven't yet found such a chip/converter suitable for audio. Maybe you know of such a converter/design?
I have had contact with a Danish audio manufacturer (considered high-end) and he told me that for classical music the SACD format is positively preferred. Others say something different, though - my personal experience is that PCM and DSD each seem to have sonic imprints that may be somewhat unique to them (I realize implementation has a lot to say - and not being humble, no, I may not be able to discern close designs from eachother ... ).
In the marketplace, what I notice is that SACD title issues now have reached >5000 and DVD-A is declining - as far as I know. So maybe SACD is what will happen in the future. Also with high capacity discs available, such as blu-ray, I consider it likely that recording rates will go up in the near future.
Well, yes, that's where I am with this. I'd appreciate if you/others have comments ...
All the best to your evening, Bruno! Here in Denmark, right now the sun is setting - slowly painting the sky orange/reddish - and the birds are singing. It's a good experience
Regards,
Jesper