Short answer: the MOTU M6. It ranks #5 of 17 audio interfaces by measured performance (rated 3.8/5) at $449.95 and is still sold new; the MOTU 624 ranks #8 (rated 3.7/5) and is discontinued, so it is only an option used.
What the MOTU M6 does well: Audio Science Review measured 112 dB SINAD from its ESS Sabre32 Ultra DAC, clean for nearly all listening. The tradeoff: MOTU doesn’t publish a 32 ohm headphone power figure, and Audio Science Review found the headphone output poor into low impedance loads and its recording converter weaker than its DAC.
Why pick the MOTU 624: Audio Science Review measured 112 dB SINAD from its outputs, clean enough for nearly all listening. The catch: It is discontinued and no longer sold new.
Buy the MOTU M6. It is rated higher and still sold new, while the MOTU 624 is discontinued.
Still deciding? The full Headphone Amps and DACs rankings cover every ranked option.
Specifications Side By Side
| MOTU M6 | MOTU 624 | |
|---|---|---|
| Price | $449.95 | $795 Discontinued |
| Ranked | #5 of 17 in Audio Interfaces | #8 of 17 in Audio Interfaces |
| Device Type | Audio interface | Audio interface |
| SINAD | 112 dB (measured by Audio Science Review) | 112 dB (measured by Audio Science Review) |
| Inputs | 4 XLR/TRS combo (mic/line/Hi-Z), 2 balanced 6.35 mm line, USB-C, MIDI in | 2 XLR mic, 2 front-panel Hi-Z guitar, 8 ADAT optical |
| Outputs | 4 balanced TRS line outs, 2 headphone, MIDI out | dedicated main outs, 8 ADAT optical |
| Headphone Outputs | 2 x 6.35 mm | 1 x 6.35 mm |
| Balanced Output | Yes (TRS monitor outs) | - |
| DAC Chip | ESS Sabre32 Ultra | ESS Sabre32 |
| Volume Control | Hardware knob | - |
| Dimensions | 9.2” x 4.7” x 1.8” (234 x 120 x 46 mm) | 8.6” x 1.7” x 7” (218 x 44 x 178 mm) |
| Weight | 2.1 lbs (975 g) | 2.2 lbs (1.0 kg) |
Related Amp and DAC Comparisons
More worthwhile head-to-heads for MOTU M6:
- Lynx Hilo 2 USB vs MOTU M6
- MOTU M6 vs MOTU UltraLite-mk5
- MOTU M2 vs MOTU M6
- MOTU M4 vs MOTU M6
- MOTU M6 vs RME Fireface UFX III
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 M6: $449.95 Amazon $449.95 eBay
Pros: Audio Science Review measured 112 dB SINAD from its ESS Sabre32 Ultra DAC, clean for nearly all listening. It offers four XLR/TRS combo inputs for mic, line or instrument, two more balanced line inputs, four balanced TRS outputs, two headphone outputs, MIDI in and out and a hardware volume knob.
Cons: MOTU doesn’t publish a 32 ohm headphone power figure, and Audio Science Review found the headphone output poor into low impedance loads and its recording converter weaker than its DAC. The Topping E2x2 rates higher for much less if you only need two inputs.
Full MOTU M6 review and specifications →
| Released | 2022 (4 years ago) |
|---|---|
| Balanced Output | Yes (TRS monitor outs) |
| DAC Chip | ESS Sabre32 Ultra |
| Device Type | Audio interface |
| Dimensions | 9.2” x 4.7” x 1.8” (234 x 120 x 46 mm) |
| Headphone Outputs | 2 x 6.35 mm |
| Inputs | 4 XLR/TRS combo (mic/line/Hi-Z), 2 balanced 6.35 mm line, USB-C, MIDI in |
| Outputs | 4 balanced TRS line outs, 2 headphone, MIDI out |
| SINAD | 112 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
| Weight | 2.1 lbs (975 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
MOTU 624: $795 Discontinued eBay
Pros: Audio Science Review measured 112 dB SINAD from its outputs, clean enough for nearly all listening. Alongside two XLR mic inputs and two front panel guitar inputs it has eight channels of ADAT optical in and out for expanding the setup, and the reviewer found its browser based control software rich and flexible.
Cons: It is discontinued and no longer sold new. Audio Science Review found its ADC a weak link next to other interfaces it had tested and its DAC short of the best consumer DACs, and MOTU doesn’t publish a 32 ohm headphone power figure. The MOTU UltraLite-mk5 measures similarly and is still sold.
Full MOTU 624 review and specifications →
| DAC Chip | ESS Sabre32 |
|---|---|
| Device Type | Audio interface |
| Dimensions | 8.6” x 1.7” x 7” (218 x 44 x 178 mm) |
| Headphone Outputs | 1 x 6.35 mm |
| Inputs | 2 XLR mic, 2 front-panel Hi-Z guitar, 8 ADAT optical |
| Outputs | dedicated main outs, 8 ADAT optical |
| SINAD | 112 dB (measured by Audio Science Review) |
| Weight | 2.2 lbs (1.0 kg) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons