@generic_name already mentioned the Vestrax similar product, I’ve go vague memory of one or three others like this over the decades.
All what they said plus if this thing is just taking line in levels for input, the cutting head stands a great chance of overload very easily. Unless of course there’s a digital limiter circuit in there but that would degrade the sound with transients most likely.
Hi! I’ve made/recorded/mixed/produced a few hundred things that ended up on vinyl and know a bunch of people who’ve done the like. For decades now the final master recording shipped off to the pressing plant is far more likely to be digital than analog. DATs, CD-Rs, various digital tapes, HDDs, etc.
That wouldn’t work. Microphones on their own dont produce enough voltage to drive something like this. One could in theory use a mic & pre-amp + impedance matching to get the input levels right.
