Short answer: the MOTU M4. It ranks #7 of 17 audio interfaces by measured performance, rated 3.8/5, at $279.95; the RME Babyface Pro FS ranks #10, rated 3.6/5, and costs $849, so there is not much of a tradeoff to weigh.
The case for the MOTU M4: Audio Science Review measured 111 dB SINAD from its ESS Sabre32 Ultra DAC, clean for nearly all listening and competitive with good budget DACs. The catch: MOTU doesn’t publish a 32 ohm headphone power figure, and Audio Science Review measured just 18 mW into 300 ohms, calling the headphone amplifier its weakest part, so demanding headphones may run out of volume.
The case for the RME Babyface Pro FS: Audio Science Review measured 108 dB SINAD from its outputs, clean enough for nearly all listening. Watch for: It costs far more than the MOTU M2, which measured a higher SINAD and rates higher.
Buy the MOTU M4. It is rated higher than the RME Babyface Pro FS and costs less, so only choose the other one for a particular feature it does better.
Looking for alternatives? See the complete Headphone Amps and DACs rankings.
Specifications Side By Side
| MOTU M4 | RME Babyface Pro FS | |
|---|---|---|
| Price | $279.95 | $849.00 |
| Ranked | #7 of 17 in Audio Interfaces | #10 of 17 in Audio Interfaces |
| Device Type | Audio interface | Audio interface |
| SINAD | 111 dB (measured by Audio Science Review) | 108 dB (measured by Audio Science Review) |
| Inputs | 2 XLR/TRS combo (mic/line/Hi-Z), 2 balanced 6.35 mm line, MIDI in, USB-C | 2 XLR mic/line, 2 6.35 mm line/instrument, optical ADAT/S/PDIF, USB |
| Outputs | 4 balanced 6.35 mm TRS, 4 RCA (mirrored), headphone | 2 XLR line, 2 headphone |
| Headphone Outputs | 1 x 6.35 mm | 2 (6.35 mm and 3.5 mm) |
| Balanced Output | Yes (TRS monitor outs) | Yes (XLR outs) |
| DAC Chip | ESS Sabre32 Ultra | - |
| Volume Control | Hardware knob | Hardware knob |
| Dimensions | 8.3” x 1.8” x 4.3” (210 x 45 x 108 mm) | 4.3” x 1.4” x 7.1” (108 x 35 x 181 mm) |
| Weight | 2 lbs (920 g) | 1.5 lbs (680 g) |
| Output Power (300 ohms) | 18 mW (measured by Audio Science Review) | - |
Related Amp and DAC Comparisons
How MOTU M4 compares with other leading options:
- Topping M62 vs MOTU M4
- Topping E2x2 vs MOTU M4
- Lynx Hilo 2 USB vs MOTU M4
- MOTU M4 vs MOTU UltraLite-mk5
- MOTU M4 vs MOTU M6
Prices on this page were last checked October 13, 2026 at 3:17 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Amps and DACs In Full
MOTU M4: $279.95 Amazon $279.95 eBay
Pros: Audio Science Review measured 111 dB SINAD from its ESS Sabre32 Ultra DAC, clean for nearly all listening and competitive with good budget DACs. It adds two balanced line inputs to the two XLR/TRS combo inputs, has four balanced TRS outputs with mirrored RCA outputs, MIDI in and a hardware volume knob, and Audio Science Review found its recording converter better than many computer interfaces.
Cons: MOTU doesn’t publish a 32 ohm headphone power figure, and Audio Science Review measured just 18 mW into 300 ohms, calling the headphone amplifier its weakest part, so demanding headphones may run out of volume. The Topping M62 rates higher for less.
Full MOTU M4 review and specifications →
| Released | 2020 (6 years ago) |
|---|---|
| Balanced Output | Yes (TRS monitor outs) |
| DAC Chip | ESS Sabre32 Ultra |
| Device Type | Audio interface |
| Dimensions | 8.3” x 1.8” x 4.3” (210 x 45 x 108 mm) |
| Headphone Outputs | 1 x 6.35 mm |
| Inputs | 2 XLR/TRS combo (mic/line/Hi-Z), 2 balanced 6.35 mm line, MIDI in, USB-C |
| Output Power (300 ohms) | 18 mW (measured by Audio Science Review) |
| Outputs | 4 balanced 6.35 mm TRS, 4 RCA (mirrored), headphone |
| SINAD | 111 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
| Weight | 2 lbs (920 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
RME Babyface Pro FS: $849.00 Amazon $849.00 eBay
Pros: Audio Science Review measured 108 dB SINAD from its outputs, clean enough for nearly all listening. It is well equipped, with two XLR mic inputs, two instrument inputs, optical ADAT or S/PDIF input, balanced XLR monitor outputs and two headphone jacks (6.35 mm and 3.5 mm). Audio Science Review praised its compact hardware and noted it runs without an external power supply.
Cons: It costs far more than the MOTU M2, which measured a higher SINAD and rates higher. RME doesn’t publish a 32 ohm power figure, and Audio Science Review found the headphone output fine for casual monitoring but short on power for difficult or low impedance headphones.
Full RME Babyface Pro FS review and specifications →
| Released | 2019 (7 years ago) |
|---|---|
| Balanced Output | Yes (XLR outs) |
| Device Type | Audio interface |
| Dimensions | 4.3” x 1.4” x 7.1” (108 x 35 x 181 mm) |
| Headphone Outputs | 2 (6.35 mm and 3.5 mm) |
| Inputs | 2 XLR mic/line, 2 6.35 mm line/instrument, optical ADAT/S/PDIF, USB |
| Outputs | 2 XLR line, 2 headphone |
| SINAD | 108 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
| Weight | 1.5 lbs (680 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons