That's normal. Use feet to give it some air flow if you are concerned.

Expect RME devices to be designed properly. It is always better (and a good sign) if heat is noticeably released to the outside than it is accumulated inside with a fanless design.

Therefore I would order the interface based on your demands and not based on any temperatures.

The flagship interfaces like UFX II / + (also the 802) have besides more ports / features one additional advantage.
They suppress power-on crackling on all analog outputs, not only for the headphone outputs.

Maybe my excel comparison sheet can help you to find the one with the proper features:
Blog article: https://www.tonstudio-forum.de/blog/ind … B-MADIfac/
Direct Link to Excel: https://www.tonstudio-forum.de/index.ph … -04b-xlsx/
Also available as PDF there.

If you should choose the UFX II for this power-on dampening on all analog ports and other  features you should also consider the UFX+.

I personally am the opinion, that it's always an advantage to have a Plan B.
The plan B here is , that you have two different possibilities to connect to your computer: through USB3 and Thunderbolt.

Even USB2 operation is possible in cases where your computer has no USB3 port free. Then only the USB transport of MADI channels from/to computer does not work. The routing from MADI inputs to any other channel locally on the UFX+ still works.

Next advantage .. in case that you need to expand with external adda converter or preamps, especially if you want to record at higher sample rates (maybe for special projects with high quality demands), then MADI gives you 64 channels, where still 32 remain at double speed (16 at quad speed).
You have the flexibility to connect more devices through MADI and due to longer cable length, you can distribute devices/preamps better through different rooms or on stage.
You can add e.g. 8 preamps to one MADI port (ring structure) and the cable length between each of these cables may be up to 2km. Patch cables for this multimode fiber cable (OM3 or OM4) are usually available up to 50m.

Or in other words, for only a little higher price much more flexibility for the future.

Besides this I regard it as a general advantage, that the UFX II / + have already two headphones outputs of very good quality.

Another thing is, that UFX II and UFX+ use the MADIface USB driver which allows even slightly lower ASIO buffer sizes of 32 samples at single speed.

For better compatibility operability with the older model "UCX" the "UCX II" got the same (older) USB driver, this has 48 samples as lowest ASIO buffer size. Not a very big difference but if you should want for lowest ASIO buffersizes compareable to the HDSPe PCI/PCIe driver, then the MADIface and Thunderbolt driver give you an advantage here.

Here you can compare the RTL (round trip latencies) if different RME products:

My ex. fireface 400 was also extremly hot no matter what the season is. I always have my units on cork plugs to get better air circulation.

Now I got myself UCX and this card is not heating at all, I was amazed. I also have unit on cork plugs like I did FF400.

Hi Manuel,

> Looking at that spreadsheet it looks like the UCX II also features power-on pop suppression

oh sorry then I had this wrong in my mind.

> I see, however, that the UCX II does not have a mechanical power switch like the old UCX or the UFX;
> instead, it the data knob is held down for 2 sec. to power on and off. Do you know if the default state is OFF
> when the power supply is connected? This matters because I power the gear in my rack using a remote control.
> If the default state is OFF, this will be no good, as I'll still have to reach for the UCX knob on the rack.
> Maybe there is a way to set the default state?

I have a power strip myself with one on/off switch, which turns all devices on and off. Assuming the UCX II has the same implementation like ADI-2 Pro FS R BE and 12Mic then the power state is being remembered, so it should power-on as soon as you remotely power on your power strip.

Expect RME devices to be designed properly. It is always better (and a good sign) if heat is noticeably released to the outside than it is accumulated inside with a fanless design.

> Which RME interface(s) do you currently have?

UFX+------12Mic, Octamic XTC
|  |
|  +---------ADI-2 Pro FS R BE----> Active Monitors/Phones (Recording)
|
+------------ADI-2 Pro FS R BE ---> HiFi

RayDAT, but currently not in use.

See also: https://www.tonstudio-forum.de/blog/ind … -DURec-DE/

Temperatures are not a problem, just make sure that the heat does not build up or accumulate by stacking several units in a rack.

Just leave some space above and below each unit so that the heat from each unit can be dissipated by airflow and not accumulate.

I have my 2 multi-effects that hardly gets warm in a 2RU rack directly above each other.

UFX+, XTC and 12Mic have more I/O ports, features, better technical specs and of course produce a little bit more heat because of that. But the devices are designed for this purpose.

So you just have to e.g. dimension the rack accordingly. I have installed the three units in a rack with 4 RU height and that's it.