For the nit-pickers and nerdy ones here, I’m giving the specs and technical sheets. For all the others, you can just go to the next page to see how the DAC performs.
Internal circuit architecture
The xDuoo XD-05 Plus ditches the AK4490 for another chip from Asahi Kasei, the AK4493.
A chip that we’ve encountered more than I could say now, for good reasons. It supports PCM stream up to 32bit/768kHz, offers an S/N Ratio of 123dB, and a THD as low as -113dB. 8 different filters are available and, like before, the DAC is issued from the famous Velvet Sound series.
To feed the DAC, two different chips are used :
- a Cirrus Logic CS8422 for optical/coaxial. This chip supports AES3 and S/PDIF interface, but only up to 24bit/192kHz (quite enough I should say)
- an Xmos XU208 for USB. A multi-core chip, fully compliant with USB 2.0 specification, and advertised as a “major upscale” from the previous U8.
Moreover, the XD-05 Plus now gets an FPGA chip, provided by Altera. Thanks to that, users will now be able to enjoy their DSD through the Coaxial/Optical input, but only up to DSD64.
If the first amp was able to output 500mW of power at 32ohms, the XD-05 Plus doubles that value. To do so, xDuoo simply doubled the number of Op-Amp, some nice OPA1612 from Texas Instruments.
And, the cherry on top, those two op-amps can be replaced by the one you want. All you need is to open the front panel and install the new one where the previous chip were. A nice option, that reminds me of the FiiO E12A, where you could get the Op-Amp of your choice to fine-tune your amp.
- THD is now 0.0016% (against 0.0025%)
- S/N raised to 117dB (against 112dB)
The built-in battery is now rated at 5000 mAh, a whopping 1000mAh more.
The official battery life is supposed to range from 13h (USB in), to 40h (Aux in). During my review, I easily reached the 13h through the USB port, proving xDuoo numbers right (to my surprise).
On a different note, charging the xDuoo XD-05 Plus is, again, painfully long: 4.5h with a “fast charger” (2Ah/5V) and 11h with the classic computer port (500mAh/5V). So each time I used it with a computer, I plugged it for charge too, so I could get enough power when on the go.
To sum it up, good battery life but painstakingly long charge time.
- Type: DAC / Headphone amplifier
- DAC: AKM AK44903
- LPF: 2x Ti OPA1612
- BUF: 2x BUF634
- Screen: 0.91-inch Oled screen
- Outputs: 6.35mm headphone out
- Input: USB/COAXIAL/OPTICAL/AUX
- Volume Knob: ALPS Analog
- Drive Ability: 16-600 ohms
- Battery: 3.8V/5000mAh
- USB: PCM up to 32bit-768kHz, DSD64-256
- Coaxial/Optical: up to 24bit-192kHz, DSD64
- Crosstalk : > 75dB
- SNR : > 117dB
- THD : < 0.0016% (USB/SPDIF) / < 0.0009% (Aux)
- Line level : 2.1Vrms
- Gain : +6/+9/+16dB
- Output Power 6.35mm : 1000mW 32ohm
- Power input : USB-C
- Size : 139 mm x 75mm x 23mm
- Weight: 280g
The review continues on Page five, after the click HERE or by using the jump below.