D3 24-bit DAC / Headphone Amp Tech Specs
Full-scale output -- 2.0V RMS
Frequency response -- 10Hz-25kHz (+/- 0.5dB)
SNR -- (DC to 20kHz) >110dB
THD+N -- (1kHz FS 96 kS/s) <0.002%
Crosstalk -- -110dB
USB transfer mode -- Asynchronous (dual clock)
USB device class -- Type 1.1 or above
Input -- USB Audio
Input bit depth -- 24 bit (upsampled)
Input sample rate -- 32kHz-96kHz - native playback, 188.2kHz, 192kHz - re-sampled to 96kHz for playback
Output -- Analog audio minijack
Output impedance -- 10 ohms
Suggested headphone impedance -- 12 ohms to 10K ohms
Headphone amplifier -- LME49726
D/A converter -- AKM4396
USB controller -- TI1020B
Power requirement -- USB 5V DC, 200mA
USB power filtering -- 2-stage redundant regulation
Product dimensions -- 6.5 x 2 x 1 cm (including USB connector)
Shipping weight -- 1.0lbs (0.5kg)
Operating Temperature: 32 to 95 degrees F
Non-operating Temp: -4 to 113 degrees F
Relative Humidity: 5% to 95% non-condensing
1/8" to 1/4” adapter cable
D3 Internal Converter
The heart of the D3 is the AK4396 DAC, well regarded for its low noise and high fidelity. Due to the high signal-to-noise specs of the AK4396 and the added benefit of double redundancy power source conversion and filtering, the D3 presents impressive low noise and low distortion characteristics. The D3 can process digital audio at any bit depth up to 24 bits and any sample rate up to 192kHz. D3 pads (upsamples) all bit depths internally to 24 bits, thus achieving a higher signal-to-noise ratio.
D3 Headphone Amplifier
The D3 contains a high-performance headphone amplifier based on the LME49726 low-noise opamp. This amp is able to provide low-impedance, high-fidelity audio and a 2-volt output which easily drives a wide range of headphones, including headphones with impedances as low as 12 ohms. The D3’s relay-controlled stereo outputs can also be connected to any system with an analog audio input, such as Audioengine powered speakers, for example.
The D3 is powered directly from the USB bus and power is passed through two stages of regulation to ensure no USB bus power variations affect the audio quality. This low-noise, low-ripple power supply is located on a separate circuit board for extra isolation and thermal management.
D3 Volume Control
Volume is controlled from the computer’s OS and is implemented in the D3 as a digitally-controlled analog volume control.