Their DAC daughter board is not enough already. I would like to try more. No DSD too. All I know for now is up to 24/192. So, let's upsample everything as high as possible and prey we notice the difference
I wouldn't get too hung up on 24/192 or even 32/384, unless your music is natively mastered and the copy itself is in either. Subjective tests did have some consistency in picking out differences with upsampling, but there was one white paper from the last decade that figured out the reason for it: upsampling adds very high frequency noise that while itself inaudible affects the rest of the range in how the driver needs to move in order to reproduce it. In other words, the difference, or "improvement," is just added noise and distortion.
Not sure if a DSD DAC will do that
but nowadays DACs that can do true DSD and PCM* AFAIK will decode them as normal. No DSD to PCM conversions, but they won't upsample PCM at the same very high sampling rates (much less at 1bit). AFAIK, DAC chips nowadays don't even work with upsampling chips nor have they become integrated into the chips, unless the specific DAC has a switch (which indicates it has the upsampling chip), so if you hear differences in most DACs, it's most likely due to the circuit as a whole just having less noise.
If you're going to get into DSD then get DSD compatible DACs. Otherwise, any 24/192 DACs will work well enough since 1) CDs and most regular streaming are on 16/44.1 anyway and 2) FLAC downloads are at 24/96. 24/192 is mostly just future proofing in case FLAC downloads move up to that (although not likely - the reason why they sell FLAC only in 24/96 now is because that's the sampling rate when mastering the album, and given the proliferation of 24/192 compatible DACs including smartphones let alone DACs, 16/44.1 just takes up server space).
*ie, DSD is 1bit/2.8Mhz, or higher; used to be they'd cite only the DSD spec and it can run Redbook, and then initially 24bit DACs just converted DSD to PCM. Some DACs now can do both without conversion, but what you'd normally see is they're rated at 32/384 or 24/196.
I'm quite old already, You know.
That's the thing...if you have higher frequency hearing loss, it's harder to guarantee you'll hear a difference, not to mention the difference with upsampling has been due to added noise and consequently, driver distortion.
Can You help me pair the HPA V281 with some cool DAC?
I don't really get fussy with DAC specs apart from whether there's feedback that there's an obvious flaw in the sound (like some Rega CDPs sounding too dark, or some Cambridge CDPs that image the drums too far forward) or the specs (single ended line voltage output too far below or above Redbook standard) so I can't help there.