I'm trying to get a Domesday Duplicator setup, as I have a ton of rare-ish LDs I'd like to preserve. The DD official website and Github page hasn't been super useful, and has left me with a lot of questions. Does it only work with a Pioneer LD-V4300D, or can I use another player? How do I attach the board(s) to the player? I can probably figure out how the ld-decode software works, but I'm totally lost on the hardware. Once I figure it out, I'd like to make a YouTube video about the process, as well as host the rips I take on my website. Can someone point me in the right direction?

Happycube knows all the answers to your questions.

You need a player with a raw EFM output. There are a few, I think they are all earlier decks, pro mostly.

I know someone using an LD-S9 with a DD setup, if I'm not completely mistaken you grab the "RF" signal on the board somewhere.
Usually the point is labeled "RF" so you basically cannot miss it

I only have 1 player, an LD-W1. I'd rather not use a dual disc system for domesday so I'm expecting to buy a new machine specifically for this project. I wonder what the cheapest player I could get that has an easily accessible RF output...

Well aren't pro decks usually fairly cheap because they're otherwise lacking in features?

The LD-V4200 has an EFM out port so that's one.

EFM relates to digital audio. It would go to EFM decoder which would convert it from 14 to 8 bit signal and from there to DAC and then output. Some Pioneer players that didn't had digital audio decoders built in had those ports to hook up to external decoder. This should not matter since you're looking for RF. EFM is derived from RF.
As far as I know basically any player should work, it's just that those industrial Pioneers have RF directed to neatly labeled test pins and they have serial interface for control from PC. And 4300 in particular can read NTSC/PAL. So it's a matter of convenience.
So how I see it, if you don't care about PAL, you can go with other industrial Pioneer, but then serial interface pinout and command set might differ (I think 1k and 6k used different commands and there are 2 or 3 different pinouts). I haven't checked how far is their control program, maybe it addresses this. If not - not a big deal, though. You can find those commands in manuals and just use any terminal pretty much.
And if not industrial Pioneer, then you can use whatever, but it might be difficult to hook to RF and it might not have convenient way to control unit, for example to skip those CAV PSCs.
What you actually do with a player - you just solder 2 wires to board. And that's your input. I think that's pretty much it. And then you sandwich domesday board with 2 other boards like Arduino shields and one of them has USB interface ports and you hook that to PC. None of that is really complicated, if you get pre-assembled domesday, it's price tag that killed it for me. Which with shipping and tax was around 400 at the time.

Woah, I didn't know they had pre-assembled boards. I'd gladly pay a premium just to make sure I don't fry the board with my awful soldering. Where can I grab one at?

Also thanks for the info, it'll be a big help.

Ah, no I meant it's not difficult if you can get assembled board. In that sense. Since recently somebody was recruiting people in this forum to get preassembled DD boards. That part is most difficult.
So I was calculating 400 as grand total for everything. That would be over 100 for Nano and Cypress FX3 and less for Domesday PCB. And I mailed Domesday layouts and component list to several local workshops that advertise repair of electronics and soldering and 1 got back to me and said they could assemble it. But I decided it was all too expensive.
If you can get one assembled in China it should be cheaper potentially. And maybe those other two boards are cheaper now too.

It works with pretty much any working LD player, most of them have RF taps somewhere. The 1995 and later CLD's all have it labeled on a 11-pin header, which is nice. The EFM port was only used to see what the players did with the EFM on the disk.

I don't know of any pre-made boards right now alas.

I'm going to be getting one of these soon, but I have a question about the size of the raw files; about how many GB/TB is it for a single two-sided disc?

Uncompressed about 150-200GB/CLV side and about half that when compressed using FLAC.

The DD project was initially designed to work with the Pioneer LD-V4300D laserdisc player, as it provided the necessary features and controls to interface with the Domesday Duplicator hardware. However, it's possible that other players with similar functionality and compatible control interfaces could work as well. You may need to consult the DD project's official documentation, forums, or community for specific details on alternative player compatibility.