Short answer: the SMSL D12. It ranks #23 of 43 DAC and headphone amp combos by measured performance, rated 4.2/5, at $149.59; the Fosi Audio K7 ranks #26, rated 4.1/5, and costs $199.99, so there is not much of a tradeoff to weigh.
The case for the SMSL D12: Audio Science Review measured 115 dB SINAD, which puts its noise and distortion at the point of being inaudible. Watch for: It has only a 6.35 mm output with no balanced jack and no optical or coaxial input.
What the Fosi Audio K7 does well: Audio Science Review measured a SINAD of 116 dB, so its noise and distortion are inaudible. The tradeoff: Fosi Audio doesn’t publish a 32 ohm power figure, so its headroom for hard to drive headphones is unclear.
Buy the SMSL D12. It is rated higher than the Fosi Audio K7 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Looking for alternatives? See the complete Headphone Amps and DACs rankings.
Specifications Side By Side
| SMSL D12 | Fosi Audio K7 | |
|---|---|---|
| Price | $149.59 | $199.99 |
| Ranked | #23 of 43 in DAC and Headphone Amp Combos | #26 of 43 in DAC and Headphone Amp Combos |
| Device Type | DAC and headphone amp | DAC and headphone amp |
| SINAD | 115 dB (measured by Audio Science Review) | 116 dB (measured by Audio Science Review) |
| Output Power (32 ohms) | 300 mW (manufacturer rated) | - |
| Headphone Outputs | 6.35 mm | 3.5 mm, 4.4 mm balanced |
| Balanced Output | No | Yes (4.4 mm) |
| Inputs | USB-C, Bluetooth | USB-C, optical, coaxial, Bluetooth, 3.5 mm mic |
| Outputs | RCA | RCA |
| DAC Chip | AK4493S | AK4493SEQ |
| Dimensions | 5.5” x 1.3” x 4” (139 x 33 x 102.5 mm) | - |
| Weight | 0.8 lbs (355 g) | - |
| Bluetooth Codecs | - | SBC, aptX HD, aptX LL |
| Volume Control | - | Hardware knob |
| Equalizer | - | Yes (bass and treble knobs) |
Related Amp and DAC Comparisons
More worthwhile head-to-heads for SMSL D12:
- SMSL DL100 vs SMSL D12
- SMSL DS20 vs SMSL D12
- Tanchjim Luna vs SMSL D12
- Khadas Tone2 Pro vs SMSL D12
- Fosi Audio SK02 vs SMSL D12
Prices on this page were last checked October 11, 2026 at 4:59 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.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Amps and DACs In Full
SMSL D12: $149.59 HiFiGo eBay
Pros: Audio Science Review measured 115 dB SINAD, which puts its noise and distortion at the point of being inaudible. SMSL rates it at 300 mW into 32 ohms, enough for most headphones, and it adds Bluetooth alongside USB C plus RCA outputs for powered speakers.
Cons: It has only a 6.35 mm output with no balanced jack and no optical or coaxial input. The Tanchjim Luna rates higher with similar SINAD for less, and 300 mW is not enough for demanding planar magnetic headphones.
Full SMSL D12 review and specifications →
| Balanced Output | No |
|---|---|
| DAC Chip | AK4493S |
| Device Type | DAC and headphone amp |
| Dimensions | 5.5” x 1.3” x 4” (139 x 33 x 102.5 mm) |
| Headphone Outputs | 6.35 mm |
| Inputs | USB-C, Bluetooth |
| Output Power (32 ohms) | 300 mW (manufacturer rated) |
| Outputs | RCA |
| SINAD | 115 dB (measured by Audio Science Review) |
| Weight | 0.8 lbs (355 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Fosi Audio K7: $199.99 Amazon eBay
Pros: Audio Science Review measured a SINAD of 116 dB, so its noise and distortion are inaudible. It is unusually flexible for the money, with USB, optical, coaxial and Bluetooth inputs (SBC, aptX HD, aptX LL), RCA line out, a 4.4 mm balanced headphone jack, a microphone input and bass and treble knobs.
Cons: Fosi Audio doesn’t publish a 32 ohm power figure, so its headroom for hard to drive headphones is unclear. The SMSL DS20 rates higher for a little less, and the Fosi Audio SK02 rates slightly higher for much less. Its Bluetooth lacks AAC and LDAC.
Full Fosi Audio K7 review and specifications →
| Released | Apr 2025 (1 year ago) |
|---|---|
| Balanced Output | Yes (4.4 mm) |
| Bluetooth Codecs | SBC, aptX HD, aptX LL |
| DAC Chip | AK4493SEQ |
| Device Type | DAC and headphone amp |
| Equalizer | Yes (bass and treble knobs) |
| Headphone Outputs | 3.5 mm, 4.4 mm balanced |
| Inputs | USB-C, optical, coaxial, Bluetooth, 3.5 mm mic |
| Outputs | RCA |
| SINAD | 116 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons