Topping D70 is a perfect pair for a high-end headphone amplifier. This DAC is stocked with plenty of high quality components, including two Asahi Kasei Microdevices AK4497 DAC chips that are coupled with low-noise, low-dropout linear regulators. It has AES, USB, optical, and coaxial inputs, all of which support 24-bit 192k audio. It has balanced XLR and single-ended RCA outputs.
Dual AK4497 DAC
D70 uses one AKM AK4497 DAC chip per channel. Thanks to that sound and channel separation is vastly improved over using only one AK4497 DAC chip. The AK4497 from Asahi Kasei Microdevices (AKM) is a new generation Premium 32-bit 2-channel DAC with VELVET SOUND technology, achieving industry’s leading level low distortion characteristics and wide dynamic range. The AK4497 integrates a newly developed switched capacitor filter “OSR Doubler”, making it capable of supporting wide range signals and achieving low out-of-band noise while realizing low power consumption. Moreover, the AK4497 has sixtypes of 32-bit digital filters, realizing simple and flexible sound tuning in wide range of applications. The AK4497 accepts up to 768kHz PCM data and 22.4MHz DSD data, ideal for a high-resolution audio source playback. These chips allow THD+N to reach -116dB and offer a dynamic range of 131dB. In addition, these chips support high sampling rates: PCM up to 32bit 768kHz and DSD up to DSD512 Native. Customized Thesycon drivers for Windows 7 and above allow to maximize D70’s performance when using a PC as a source.
The Asahi Kasei Microdevices AK4118 chip in D70 is used for optical, coaxial and AE inputs. AK4118 is a digital audio transceiver. It is the lowest jitter S/PDIF receiver currently on the market and allows for sampling rates of 24bit 192kHz to be achieved. The AK4118 can automatically detect a Non-PCM bit stream.
USB XMOS XU208
USB interface in Topping D70 is controlled by the second generation XMOS XU208 USB interface, well known to audiophiles and offering an exceptionally transparent sound. XU208 chip is a representative of the xCORE-200 Series by XMOS and is a 32-bit mulitcore microcontroller characterized by its low latency and timing determinism. Unlike conventional microcontrollers, XU208 is cabable of exectuing multiple real-time tasks simultaneously and communicate between tasks using a high speed network. XU208 chip supports sampling rates of up to 32bit 768kHz in PCM and up to DSD512 Native.
Selectable output port and a myriad of inputs
D70 has both balanced XLR and single-ended RCA outputs. It can work with either XLR or RCA output only, or with both XLR and RCA together, making it very convenient for using with multiple systems. This makes Topping D70 an ideal candidate for a centerpiece of any audio setup. D70’s rear panel is also packed with inputs, these include: AES/EBU, coaxial SPDIF, optical Toslink, I2S LVDS HDMI with several selectable modes to adapt to various I2S LVDS devices, and of course a USB input. D70 also comes with a handy remote control.
Voltage selector switch
D70 allows the user to choose the voltage: 115V for AC 100V-120V 50/60Hz, 230V for AC220V- 240V 50/60Hz. This means D70 can be used virtually anywhere in the world.
D70’s AKM AK4497 DAC chips are paired with AccuSillicon AS318-B Series Professional Audiophile Crystal Oscillators, which are an extremely low close-in phase noise and very low rms phase jitter 45.1584MHz and 49.1520MHz high-end femtosecond clocks. These allow a perfect synchronization of the data signals for an impressive jitter attenuation.
High quality circuit
D70 uses plenty of other hi-end components – 4 Nichicon FW 3300µF capacitors serve as power reserve for the AKM AK4497 and 8 Nichicon Muse capacitors are responsible for coupling the output signals. The output circuit is composed of 3 high fidelity audio operational amplifiers LME49720 by Texas Instruments. LME49720 are ultra-low distortion, low noise, high slew rate op amp chips optimized and fully specified for high performance and high fidelity. They combine advanced leading-edge process technology with state-of-the-art circuit design, these op amps deliver superior audio signal amplification for an outstanding audio performance. LME49720 op amps combine extremely low voltage noise with vanishngly low THD+N (0.00003%) to easily satisfy the most demanding audio enthusiasts. The use of Vishay high precision resistors and WIMA capacitors results in an outstanding performance. The Ultra-low noise, low voltage drop (LDO) linear regulators from Texas Instruments, the TPS7A4701 and TPS7A3301 provide power for D70, they are designed with bipolar technology for high-accuracy, high-precision to ensure clean voltage rails to maximize system’s performance, offering a very dark background.
DAC & pre-amp
D70 has an internal volume controller with attenuation from -99 dB to 0 dB which allows it to work as a pre-amplifier. The volume controller can also be disabled so D70 can operate as a DAC only with output levels at their maximums, i.e. 4Vrms for XLR and 2Vrms for RCA.
- Product type: DAC
- DAC Chip: 2x AK4497
- USB Interface: XMOS XU208
- SPDIF Interface: AK4418
- 1x I2S LVDS (HDMI)
- 1x Optical Toslink
- 1x USB-B
- 1x Coaxial SPDIF
- 1x AES/EBU
- Supported sampling rates:
- USB : PCM up to 32bit 768kHz / Native DSD up to DSD512 / DSD DoP up to DSD256
- I2S : PCM up to 32bit 768kHz / DSD up to DSD512
- Coaxial, Optical, AES : PCM up to 24bit 192kHz
- 1x Balanced XLR
- 1x Single-Ended RCA
- RCA : <0.0004% @ 1kHz A-Weighting
- XLR : <0.0004% @ 1kHz A-Weighting
- RCA : >118dB @ A-Weighting
- XLR : >127dB @ A-Weighting
- Frequency response:
- RCA : 20Hz – 20kHz (+/-0.9dB)
- XLR : 20Hz – 20kHz (+/-0.9dB)
- Voltage output:
- RCA : 2Vrms @ 0dBFS
- XLR : 4Vrms @ 0dBFS
- RCA : <2.4µVrms
- XLR : <1.8µVrms
- RCA : -128dB @ 1kHz
- XLR : -137dB @ 1kHz