If you want the full functionality of a recording interface, then you have to buy a recording interface.

First and foremost, the Octamic XTC is designed as a preamp. CC Mode came later, probably specifically for the iPAD. Works also under Windows, but this is not the usual way of connection, you don't even have an ASIO driver to access it.

Do you already have any ideas what you would like to use as recording interface ? What kind of device do you want to connect it to (Windows PC or Apple, desktop or laptop) ? What kind of I/O ports do you need ? How much should it cost ?

Ideal would be the connection to a UFX+ with MADI. Then you can integrate the XTC as an auxdevice into TotalMix FX like a channelstrip and control it remotely with TM FX. With a MADI setup you can remote control via "MIDI over MADI" and can save the MIDI cabling, which would only impose length restrictions on you anyway. With MADI cabling you could for example build a ring of 8 XTC and between each XTC the OM3/OM4 cable might even be up to 2km long.

Check the Excel in this blog article, where you can compare a few recording interfaces with each other:
https://www.tonstudio-forum.de/blog/ind … B-MADIfac/

Using MADI has the advantage to have 64ch, even in double speed (88.2/96 kHz) still 32ch.
You could also connect the XTC to a smaller interface with one or two ADAT ports.
But then you have quickly a channel reduction at higher sample rates.
And you can't expand further. Therefore IMHO UFX+ with MADI would be ideal, then you can still use ADAT and AES ports for other purposes. And you have the possibility to connect the UFX+ with either USB2 (without MADI), USB3 or Thunderbolt to the computer which gives you a lot of possibilities and options. It's also the recording interface with the best operability in stand-alone mode and DURec is excellent for either backup recordings (in parallel to DAW recording) or alternatively also in stand-alone mode.

See also other consulting threads about UFX+ with some useful information included:
https://forum.rme-audio.de/viewtopic.ph … 17#p170717
https://forum.rme-audio.de/viewtopic.php?id=33095
https://forum.rme-audio.de/viewtopic.ph … 02#p170302

1. These were the reasons why I think it is very unlikely.

2. That you already have a recording interface was unfortunately not apparent from your post, especially because you even wrote that you would use the XTC as the main interface in the studio, which was highly misleading, why I thought I would need to explain to you the difference between preamp and recording interface and that you should get a recording interface now, best with MADI support as this is the best for the integration of the XTC into a setup with scalability and remote control with TM FX (using MIDI for MADI) in mind...

It was only missing this little information from you, that the request is about the fact that you would like to use the XTC preamp as a full-fledged recording interface and whether RME would/could expand the device in that way.

> It is possible to use XTC as proper audio interface alone...

What is a proper audio interface for you ? One with TM FX ? Then the answer is NO.
But you can use the XTC as audio interface ... without TM FX.

After installing the MADIface driver you can access the Octamic XTC like an audiointerface through
a) ASIO and
b) WDM (compatibility devices for Windows and non-ASIO aware applications, the usual thing ...)
BUT WITHOUT ANY TM FX CAPABILITIES.

Here you see a screenshot of Cubase and RME driver settings:

Hint: in such a scenario with Cubase accessing both devices (UFX+ and XTC), then both need to be clock synched to each other and you need to ensure in driver settings to use the same ASIO buffer size.

Look also archive site, contains a very nice detailed summary of product capabilities of the XTC:
https://archiv.rme-audio.de/en/products/octamic_xtc.php

"OctaMic XTC goes Windows
RME released a firmware update for the OctaMic XTC (v47), and an updated MADIface series driver (v0.9573), which enable direct connection and usage with Windows computers. RME’s own Class Compliant driver adds special hardware support to reach the same legendary stability and performance as RME’s other audio interfaces. WDM and ASIO are controlled by a simple settings dialog, with options to control buffer size, sample rate, and the number and kind of WDM devices. Please note that TotalMix FX is not supported."

There are also compareable wishes from other customers, e.g. ADI-2 Pro FS with TM FX etc. For ADI-2 Pro/DAC RME told already that this wouldn't happen. FPGA is full in terms of CPU power (and most likely capacity). So no big changes like that possible. And with the XTC it will be quite similar, as I could think of, that TM FX is quite big in terms of implementation in such a FPGA. So we would talk about a complete redesign of the device...
At the moment 12Mic customers wait for the 12Mic to get Auxdevice support ...

I re-edited my post #6, please reread.

I understand your wish to get an official answer from RME, good luck with such an implementation although I fear its not possible. Besides this some more things come to my mind why such a product would not make any sense:

1. it will increase the price of the product and then it will be more expensive than an UFX+ ...

2. Higher price than UFX+ but lesser features:
    - no DURec
    - no USB3 / missing the bandwidth to connect more devices through MADI (up to 8)

And if you think about it further, if a customer needs the XTC only as preamp and if he would like to add up to 8 XTC to his MADI bus, then he has to pay 8x the increased cost. I fear such a product makes no sense.

For a recording interface not enough features and too expensive compared to an UFX+.
And for the purpose of adding one or more preamps it would be far too expensive.

My personal $0.02 on this topic ...