Why would you upsample using a non oversampling DAC? Suggest to just do a listening test using both, I expect you need to listen for a while to spot listening fatigue.
I don't have the Adagio yet, just wondering on the generally accepted method. Obviously I'll do some listening tests myself when the time comes. I seem to recall, back when I had a Metrum Hex a few years ago, that using upsampling to 176 kHz had a positive effect at the time.
Sorry this is long, but I wanted to share it because it’s relevant to pedalhead’s question. Back in 2017 I put this question to Cees:
Do you have an opinion on the difference in sound quality of a native 44.1 redbook stream versus the same file upsampled to 384k going into the USB input on the Musette? Personally I am having a hard time noticing much difference using HQplayer on my laptop to try it out...
His answer:
My opinion is that you cannot create more information as available in the red book standard. Compare a single sample with a battery having a certain voltage, it is not more than that. Up sampling has more effect on oversampling dacs as this technique will reduce ringing caused by very steep FIR filters. But as you know NOS dacs do not use steep filters so there is no risk for ringing and therefore there is no real difference between the original samples and the interpolated data created by up sampling. Further investigating from my side is that there are many algorithms to do the up sampling but some of them are not free from artefacts. Especially these artefacts can be noticed as a kind of improvement which is wrong of course.
Thanks, interesting info.
I do wish Cees/Metrum put a bit more info out there about their design approach. Same thing is happening with the DAC3 modules...they're taking orders but haven't actually posted any useful info on them yet. Metrum have been quickly replying to me about the sale of an Adagio + DAC3 modules, but when I ask about the actual changes/benefits of DAC3 I just get silence. Considering the recent events at the company, it doesn't inspire confidence.