Short answer: the Fosi Audio K7. It ranks #26 of 43 DAC and headphone amp combos by measured performance, rated 4.1/5, at $199.99; the Loxjie D40 ranks #28, rated 4.0/5, and costs $209.99, so there is not much of a tradeoff to weigh.
Why pick the Fosi Audio K7: Audio Science Review measured a SINAD of 116 dB, so its noise and distortion are inaudible. The catch: Fosi Audio doesn’t publish a 32 ohm power figure, so its headroom for hard to drive headphones is unclear.
The case for the Loxjie D40: Audio Science Review measured a SINAD of 122 dB, so its noise and distortion are inaudible. It supports LDAC Bluetooth, which the Fosi Audio K7 lacks. The tradeoff: Loxjie doesn’t publish a 32 ohm power figure, and its headphone output is a single 6.35 mm jack with no balanced headphone option.
Buy the Fosi Audio K7. It is rated higher than the Loxjie D40 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Want more options? Browse the full Headphone Amps and DACs rankings.
Specifications Side By Side
| Fosi Audio K7 | Loxjie D40 | |
|---|---|---|
| Price | $199.99 | $209.99 |
| Ranked | #26 of 43 in DAC and Headphone Amp Combos | #28 of 43 in DAC and Headphone Amp Combos |
| Device Type | DAC and headphone amp | DAC and headphone amp |
| SINAD | 116 dB (measured by Audio Science Review) | 122 dB (measured by Audio Science Review) |
| Headphone Outputs | 3.5 mm, 4.4 mm balanced | 6.35 mm |
| Balanced Output | Yes (4.4 mm) | Yes (XLR line out) |
| Inputs | USB-C, optical, coaxial, Bluetooth, 3.5 mm mic | USB, optical, coaxial, I2S, AES, Bluetooth |
| Outputs | RCA | RCA, XLR |
| Bluetooth Codecs | SBC, aptX HD, aptX LL | SBC, AAC, aptX, aptX HD, LDAC |
| DAC Chip | AK4493SEQ | 2 x ES9068AS |
| Volume Control | Hardware knob | - |
| Equalizer | Yes (bass and treble knobs) | - |
| Dimensions | - | 9.4” x 1.7” x 7.7” (240 x 43 x 195 mm) |
| Weight | - | 2.4 lbs (1,100 g) |
Related Amp and DAC Comparisons
More worthwhile head-to-heads for Fosi Audio K7:
- Fosi Audio ZH3 vs Fosi Audio K7
- SMSL DS20 vs Fosi Audio K7
- Schiit Magni Unity with Mesh DAC vs Fosi Audio K7
- Khadas Tone2 Pro vs Fosi Audio K7
- SMSL D12 vs Fosi Audio K7
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.
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The Two Amps and DACs In Full
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
Loxjie D40: $209.99 Amazon eBay
Pros: Audio Science Review measured a SINAD of 122 dB, so its noise and distortion are inaudible. It packs USB, optical, coaxial, I2S, AES and Bluetooth inputs with LDAC, aptX HD and AAC, plus RCA and balanced XLR line outputs for powered speakers or a separate amp.
Cons: Loxjie doesn’t publish a 32 ohm power figure, and its headphone output is a single 6.35 mm jack with no balanced headphone option. The SMSL DS20 rates higher for a little less, and at 1.1 kg in a wide chassis it is bulky for a desk.
Full Loxjie D40 review and specifications →
| Balanced Output | Yes (XLR line out) |
|---|---|
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC |
| DAC Chip | 2 x ES9068AS |
| Device Type | DAC and headphone amp |
| Dimensions | 9.4” x 1.7” x 7.7” (240 x 43 x 195 mm) |
| Headphone Outputs | 6.35 mm |
| Inputs | USB, optical, coaxial, I2S, AES, Bluetooth |
| Outputs | RCA, XLR |
| SINAD | 122 dB (measured by Audio Science Review) |
| Weight | 2.4 lbs (1,100 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons