Have RME made the perfect USB audio interface?
RME’s Fireface UFX has long been the company’s flagship interface, and I reviewed the very first model back in 2011. At the time, its 60 channels of simultaneous I/O (30 inputs and 30 outputs at base sample rates) was an outstanding feature, and it offered both USB 2 and Firewire 400 connections for hooking up to a computer. Such were the high technical standards of that original UFX that it was six years before its leading position was toppled — by the UFX+, introduced as part of the company’s 20th anniversary celebrations.
In essence, the UFX+ was a UFX melded with a MADIface USB, expanding the original model’s 60 channel I/O with 128 channels of MADI (AES10), delivering a whopping 188 simultaneous I/O channels — 94 in and 94 out! As the huge channel count was beyond the capability of USB 2, RME employed the novel USB 3 and Thunderbolt computer interfaces for the first time.
Six months later, in 2018, a ‘next generation’ UFX interface appeared — the UFX II — featuring upgraded converters but keeping the original I/O configuration. Indeed, the front and rear panel layouts remained virtually identical to the original UFX.
Now, five years later, I’m looking at RME’s latest flagship multi‑channel interface, the UFX III. This moniker appears logical enough, but the UFX III is not an updated UFX II. It’s actually a UFX+ Mk2 — because it replicates the massive I/O architecture of the original UFX+ (which it replaces), while updating the analogue and conversion electronics with significantly better THD and SNR figures!
So, like all its UFX forebears, the UFX III has 12 analogue inputs (eight balanced line and four mic/ instrument), plus stereo AES3 and two sets of eight‑channel ADAT — and, like the UFX+, it also has 64 channels of MADI, which my calculator totals to 94 inputs.
The output side is much the same, with 12 analogue outputs (eight balanced line and two stereo headphones), plus AES3, two sets of eight‑channel ADAT, and 64 channels of MADI, making 94 channels again. Thus 188 I/O channels altogether.
For those that like making music for bats, and who don’t need quite as many I/O channels, the UFX III supports sample rates up to 192kHz, but with a correspondingly reduced channel count. As you’d expect, each ADAT interface is limited to four channels at 96kHz and two at 192kHz, while the MADI I/O contracts to 32 and 16 channels, respectively. This means that at double sample rates the UFX III provides 54 channels in and out, while at quad sample rates it’s reduced to 34 channels each way — all still mightily impressive. These counts assume all digital channels (ADAT, MADI, and AES) are synchronised to the same word clock; the UFX III cannot accept asynchronous digital sources.
Given such a vast channel count, computer connectivity is, once more, via USB 3, and to provide the most reliable connections RME has built in sophisticated error detection/analysis, displaying the results in the Settings menu. Any found errors warrant using a different cable and/or computer port, because RME have found these to be at the root of most USB 3 connection issues. In fact, the (superbly comprehensive, 128‑page) manual provides very helpful compatibility information essentially advising the UFX III should only be connected to USB 3 sockets mounted directly on the computer motherboard (and using current chipsets from Intel, AMD, NEC/Renesas, and Fresco), and any remote USB 3 sockets connected to the motherboard via a cable are likely to introduce transmission errors, regardless of the chipset in use. So, you have been warned!
If all else fails, the UFX III also retains an option from the UFX+ which reduces the unit to a 30‑channel USB 2 interface, dropping the MADI channels from the computer interface (although they are still accessible via TotalMix FX for monitoring and external routing).
For anyone who feels 188 channels still aren’t enough, up to three UFX III units (or related Fireface units)...