Solutions for converting vinyl to 256 DSD?

Ayre produced an ADC for the purpose a while ago. The founder was convinced everyone was going to be converting their vinyl. They put a huge amount of money into its development. It was a flop. Could be exactly what you want. 

I just finished listening to the 1958 Mercury recording of Saint-Saens: Symphony No. 3 conducted by Paul Paray in 24bit 96kHz on Qobuz. It brought tears to my eyes and shivers to my arms. I noticed Paul has a couple dozen Mercury albums in the 1957 - 61 window. 

I suspect more and more old recordings will be added to streaming over time as the masters or good copies are found. 

The other issue I see is the "MetaData"...  Steaming services have these all set up.  

I suspect that the OP $ will be better spent buying second copies of the LPs that wishes to back up 

@OP. The choice in DSD ADCs is pretty limited. The Tascam DA-3000 could fit the bill. But you would need to A/B it against something like one of the two channel RME ADI Pro interfaces. If you are doing the conversion yourself, you might be surprised at the quality of a 24/96 recording. In terms of recording - as opposed to reproduction - the quality of the converters is more important than the encoding system

I hope I've understood your predicament... when I "digitize" my records I go from turntable to "USB PhonoPlus" by ART, then into pc via USB cable. Music is captured by Adobe Audition - but you can get Audacity for free to do virtually the same thing. I've been very pleased with the quality of the recordings.

Hope this helps.