As per
this post, I made a poll to gauge interest for popular and low-cost USB interfaces that could be used as a casual DAC. Most people now will agree that DAC is mostly a solved problem, needing a good implementation more than a good base D/A chip. This is why products made by big entreprises involved in the professional market for a long time should be more interesting than the "boutique-of-the-day" DACs audiophiles are so fond of; as the cheap Behringer review made by amirm showed.
To weed most of it, I chose reputable brands, and only models having a preamp for easy volume change, symmetrical/balanced output (be it TRS jack or XLR) and at least some specs on the manufacturer website. As said in my first post, I only focused on line output performances, not headphone ones; which might become the way to separate those. A short summary of the chosen models:
* Swissonic UA-2x2 (
https://www.thomann.de/intl/swissonic_ua_2x2.htm, 49€)
One of the cheapest interfaces meeting the requirements, along with Behringer's UMC22.
Specs: 24 bits/96 kHz DAC, dynamic range: 108 dB (A-weighted)
* Midiplus Studio M (
https://www.thomann.de/intl/midiplus_studio_m.htm, 77€)
Small form factor, ingenious and uncluttered front with a cute LED gain meter. Only model I chose from an almost unknown brand.
Specs at
http://www.midiplus.com/html/studioseries.html: 24 bits/96kHz DAC, dynamic range: 104 dB (A-weighted), THD+N: -98 dB
* Mackie Onyx Artist 1.2 (
https://www.thomann.de/intl/mackie_onyx_artist_1.2.htm, 79€)
Very cheap interface from Mackie. Didn't manage to find about class compliance, though.
Manuel specs: noise: 24 bits/192 kHz DAC, -85 dBu, THD < 0.001% (THD+N?)
* Presonus AudioBox iOne (
https://www.thomann.de/intl/presonus_audiobox_ione.htm, 88€)
Smallest Presonus interface meeting the requirements.
Specs at
https://www.presonus.com/products/AudioBox-iOne/tech-specs: 24 bits/96kHz DAC, dynamic range: 105 dB (A-weighted)
* Focusrite Scarlett Solo 3rd Gen (
https://www.thomann.de/intl/focusrite_scarlett_solo_3rd_gen.htm, 114€)
Newest and cheapest Focusrite having balanced outputs. The 2nd Gen lineup required you to buy the 2i2 to get these.
Specs at
https://focusrite.com/usb-audio-interface/scarlett/scarlett-solo: 24 bits/192 kHz DAC, dynamic range: 108 dB (A-weighted), THD+N < 0.002%
* Audient iD4 (
https://www.thomann.de/intl/audient_id4.htm, 125€)
Cheapest interface from a brand known for its quality. A bit like a cheap MOTU/RME on the QC and design level.
Specs from
https://audient.com/products/audio-interfaces/id4/tech-specs/: 24 bits/96kHz DAC, dynamic range: 115 dB (A-weighted), THD+N < 0.0015%
* Steinberg UR22 MK2 (
https://www.thomann.de/intl/steinberg_ur22_mk2.htm, 129€)
On the bigger and more "professional" (austere) side. Now owned by Yamaha.
Manual specs: 24 bits/192 kHz DAC, dynamic range: 104 dB (A-weighted), THD+N: 0.005%
* Roland Rubix22 (
https://www.thomann.de/intl/roland_rubix22.htm, 139€)
Still got the hitman drab look, but with classy LEDs adding some colours. Hopefully a good successor for those Edirol interfaces.
Specs at
https://www.roland.com/global/products/rubix22/specifications/: 24 bits/192 kHz DAC, dynamic range: 109 dB, "residual noise level": -94 dBu
* Presonus Studio 24 (
https://www.thomann.de/intl/presonus_studio_24.htm, 139€)
Colourful (blue) case with nice volume meters for the inputs/outputs. Surely more fancy than the Audient on the typical hifi enthusiast desk. Not a fan of the flimsy USB-C connector, though.
Specs at
https://www.presonus.com/products/Studio-24/tech-specs: 24 bits/192 kHz DAC, dynamic range: 104 dB (unweighted), THD+N: 0.001%
* Icon Cube 4Nano (
https://www.conrad.com/p/audio-interface-icon-cube-4nano-prodrive-iii-monitor-controlling-1656619, 140€)
No nonsense interface from a quite unknown (at least to me) brand.
Specs at
https://iconproaudio.com/product/cube-4nano-prodrive: 24 bits/192 kHz DAC, dynamic range: 114 dB, THD+N: -100 dB
I personally use the Swissonic right now, since I'm not Cresus, but any of those might become my next (and probably last) stepping stone. If I forgot to mention an important brand or model, please say so in the comments; since I only looked at Thomann (who wouldn't in Europe?), I might've overlooked some less known ones, like the Midiplus.