Mac or Windows ?

Unfortunately the Raydat and the UCX don't use the same driver, you can't use those on a windows computer at the same time.

RME has two different drivers for USB and two different drivers for PCIe.

USB
- "old" USB driver and
- newer MADIface driver

PCI/PCIe
- HDSPe driver
- special driver with optimizations for the HDSPe MADI FX card with the high amount of channels (3 MADI buses)

As you have then USB and PCIe card you definitively have two different drivers (I left out TB driver intentionally).

From the download page :
UCX ll driver widows :
Windows 7 to 11 PnP driver for Fireface UFX, 802, UCX, UCX II, UC and Babyface/Pro
Version 1.246.

These can run on a computer at the same time using the same driver.

A second UCXll or the bigger UFX lll would be a huge step.

Why are you talking about such an update without not knowing about his requirements?

I would wait until he tells, what port types and amount he needs.

Your suggestion here makes at the moment no sense, even worse, you are suggesting a concept which is

a) operational not so nice by having to work with two different instances of TM FX (one for each of the "isolated" devices, there is no backplane between those devices)

b) functional not so nice, either you have to route channels between those two UCX II through the DAW, which results in much higher latencies compared to converter latency or you have alternatively route them though ADAT.
After his new posting, it turns even out that he needs the ADAT inputs to connect a preamp and what not.

Are you only recording at single speed (44.1 / 48 kHz)? Then 1 ADAT input for 8 Mic Pres would be sufficient. But due to port multiplexing you have only 4ch left when using double speed (88.2/96 kHz), are you aware of this?

So when you want to add a 2nd 8-port preamp, then you need either 2 ADAT ports when exclusively working at single speed, otherwise even 4 ADAT ports if your want to work at double speed.

Another topic: in terms of clock synchronization. Does your Scarlett Preamp have ADAT inputs or Word Clock so that he could receive the clock via either an ADAT input or via WC?

Question: you mentioned a Pulse 16 .. this is a pure 16 port AD/DA converter without any Mic preamp.

So if you want to connect your 8-port Scarlet (assumed clock synch is no issue or you need to make this device to clock master) and the Pulse 16, then you would at least need 3x ADAT I/O for single or 6x ADAT I/O for double speed.

Even with two UCX II you would only have 2x ADAT I/O plus the mentioned inflexibility in terms of routing through the DAW.

An alternative would be to use the RayDAT alone and the UCX II in standalone mode.

RayDAT-----ADAT1+2 IN/OUT <----------------------> Pulse 16
                 ADAT3 IN<---------------------------------- Scarlett Preamp
                 ADAT3 OUT-----??????--------------------> Does the Scarlett have an ADAT input or WC?
                 ADAT4 IN+OUT<---------------------------> UCX II in stand-alone mode

But this setup is not so nice, as you only get 8 channels through ADAT and you can't make full use of the UCX II full capabilities in terms of DURec.

For this reason you should better get an UFX III and use the MADI Version of the Pulse 16 MX.
Full flexibility in routing. Single and double speed possible.
DURec can be used.

UFX III---------ADAT1------Scarlett Preamp, either single or double speed with 1-2x ADAT I/O
| M  |
| A  |
| D  +- >IN   Pulse 16 MX
| I   +<-OUT "
+-<+

You can use the raydat as 4 adat ins, and connect the ucx and the focusrite to it. You then have 2 ports left for the ferrofish.
You will see the 4 raydat adat ports, 32 channels at 44 or 48k, in your daw.
You will have to set up the ucx to send and receive through it Adat ports, but will not use it's driver in your daw, just tmfx to set it up once. You can use a raydat, but also a digiface usb. Both have 4 adat ports.
In the future you could also use 2 or more raydats or digifaces but only 2 of the same, but they will have to be clock synced , which depending on the exact mix devices you use can be really easy or somewhat complicated.
With the raydat syncing 2 or more cards is easier because it also has spdif and aes, which you can use to sync 2 cards and even optional WC module.
With the digifaces if you have to sync them, you will potentially loose one adat port.

I might not have read it perfectly or maybe I did. But I was under the impression that the OP thought it was not possible to use an ucx with a raydat, which of course it is. So I thought I would helpfully and simple, post that and how it is possible.
Ramses you know we have a different buying strategy, which are both valid. I could never afford nor justify yours and there are more like me, who would still like to own the amazing rme tech, but with a lower budget. So I have a second hand hdsp9652 and adi8ae, with a new Babyface pro fs, instead of an ufx with an adi. But remember I really appreciate your outlook and advice!

Yeah it sort of defeats the reason why I purchased the UCX II over the UFX II (III wasn’t out yet) I use the Aes for my Axe Fx III and Spdif for my monitor controller. What I’m trying to do is having my adat preamp back by the acoustic drums and not at the desk. I can but the only problem is that’s only 8 inputs and I usually use 12. Now, what I plan on doing is running 4 trs cables from the balanced line inputs to a mixer near the drum kit and I’ll have 12 inputs for the drums. As far as future expansion I’m still unsure where to go.

What If I use the raydat and the ucx in standalone mode only when recording drums? Is there any downfall to that as far as conversion? Is the Raydat something I can have disconnected (powered off) while not in use?

I’m fine with that considering I wouldn’t be using the Raydat every session. I can use it when needed.

I agree, but why don't you use long mic cables into the ucx mic inputs, or did I read it wrong(again)? Would that not make 12 mic inputs without hassle?