OPPO has released the Sonica DAC (Digital-to-Analog converter), a high resolution audio player designed to stream content from various sources such as a computer via USB, DLNA server or NAS drive. This audiophile DAC is capable of decoding audio files up to 24-bit / 192 kHz from formats such as PCM, FLAC, WAV and Apple Lossless, as well as DSD files. The unit is designed around the flagship ESS SABRE PRO series ES9038PRO 32-bit HyperStream DAC chip. Wireless interfaces such as Bluetooth (4.1) and WiFi (802.11.a/b/g/n/ac) are fully supported.
The Sonica DAC has both XLR balanced and RCA single-ended outputs that can be configured to bypass (fixed level) the volume control or to use the internal volume-control, making it suitable for connecting to either pre-amps or power amplifiers. In addition to the USB DAC input and network streaming, Sonica DAC also offers coaxial and optical digital inputs for additional digital audio sources.
The front panel on the Sonica DAC is clean and uncluttered with only two controls (source selection and volume) and a power button. There is also a USB port for external media. The front display utilizes a 2.8-inch black and white OLED display that is used to show the active input and the volume level as well as menu options/settings. While the resolution is somewhat limited, it gets the job done. There is no remote included with the Sonica DAC, but the Sonica app is used as a remote control. Users can also use the front panel controls to select inputs and adjust menu settings. The unit interfaces to several digital as well as analog sources.
The back of the Sonica DAC is segregated into functions. The DAC inputs include coaxial and optical Toslink interfaces along with a USB audio interface for a computer. The preout interfaces include both standard single-ended RCA jacks along with fully balanced XLR connectors. Both sets of connectors are sturdy and are easily able to handle higher quality cables that tend to be very rigid. All analog outputs are relay isolated during power on and power off to prevent unwanted transient (thumps) as circuits settle.
Balanced XLR Connectors
The balanced outputs provide better common-mode noise rejection and improves signal quality, especially with longer cable runs that are more susceptible to that annoying 60Hz hum. It also has the potential to provide better channel separation by eliminating the common ground return path. The audio output path is fully balanced from the DAC chip to the XLR jacks and driven by a pair of LME49724 ultra-low distortion (0.00003% THD), high slew-rate (±18V/μs) fully differential op-amps, specifically designed to drive 600 ohm loads for professional applications.
Single-ended RCA Connectors
The unbalanced single-ended RCA outputs are driven by a similar performing LM4562 dual ultra-low distortion (0.00003% THD), high slew-rate (±20V/μs) op-amp. Clean power is essential to achieve the high performance these parts of capable of, so the Sonica DAC delivers with the quiet linear power supply design.
Aux In Connection
The Aux In interface allows analog sources to be directly connected to the Sonica DAC. This input can be bypassed to avoid any additional degradation due to re-digitization of the audio. For convenience, the Sonica DAC uses a TI PCM1808 24-Bit, 96-kHz Stereo ADC to digitize the Aux In audio if the volume control is needed.
There is also a wired ethernet (RJ-45 LAN) jack and a USB host connector. A pair of 12V trigger in/out jacks are also provided, making it possible to turn your equipment on and off with the DAC.
The detachable power cord connects to the IEC connector with a 115V/230V selector for different regions. This is required because the toroidal transformer cannot automatically accommodate the wide voltage range like most of today's switching power supplies. A small price to pay for the quiet power provided to the analog circuits.
Design and Construction
Oppo never seems to disappoint when it comes to their sexy exterior. Like many of their other products, the Sonica DAC is well built with a heavy chassis and attractive anodized exterior with a thick front panel. Even the top panel is thicker than almost any other units I have opened.
Linear Power Supply
The Sonica DAC uses a linear power supply that provides clean power where it's needed. A toroidal transformer takes the line voltage and steps it down to the rectifiers and large filter capacitors. This then feeds the linear voltage regulators. Unlike switching power supplies, which have high frequency ripple on the power forms, OPPO opted to put substantial work into making the power to the audio circuits as clean as possible to ensure that the audio performance from the ESS DAC and associated drive circuits operate at their full potential. A pair of high quality ELNA audio capacitors (6800uF/35V) provide the bulk energy storage for the low-noise linear regulators used to generate the +12V and -12V rails that feed the analog section of the amplifiers. Additional 1.2V LDO (low drop out) regulators provide power to the digital and core sections of the ESS DAC.
A separate switching power supply is used to provide power to less sensitive circuits. The ARM processor, WiFi board and the switching power supply are separated from the analog circuits to minimize crosstalk near the sensitive areas.
Cortex®-M4 ARM Processor
The Sonica DAC uses an ST-Microelectronics STM32F401 ARM processor (delivers 105 DMIPS/285 CoreMark) to control the unit. This computer serves more as a user control device since most of the real processing is done by the ESS DAC. Nonetheless, the ARM processor has 512 Kbytes of Flash, 96 Kbytes of SRAM, supports floating point math and has many of the common serial ports (USARTs, SPI, I²C, SDIO, and USB) making it an ideal choice for this platform. Firmware can be updated using the phone app.
At the heart of the Sonica DAC is the ES9038PRO SABRE DAC, which features ESS’ patented 32-bit HyperStreamDAC technology. The specs on the ES9038PRO is impressive with a best in class 140 dB of dynamic range. The HyperStream architecture is responsible for both the outstanding sound quality of the ES9038 and the extremely low THD+N. The result is audio reproduction that is both detailed and transparent. Oppo has taken care in the layout and design of the filtering around the DAC as seen in the photo. Each power form has its own set of filter capacitors to minimize ripple, resulting in clean audio reproduction.
Control via App
Since the Sonica DAC does not include a remote, users will need to rely on the Sonica app. Customers can use their smartphone or tablet to stream and control their music content. There are four main screens that include Music, Favorites, Settings, and Devices. Both Spotify and TIDAL can run directly from the app. We also used the Pandora app to stream music. This makes it easy to operate Sonica and gives users full control of the unit.
Firmware updates for the Sonica DAC are also possible using the app and are automatically transferred over the network. The software driver download link will get you the latest driver for Windows 7/8 and Windows 10.
Most of my tests were run with the Sonica DAC driving an Oppo HA-1 headphone amplifier. A pair of Sennheiser HD600 headphones with a Silent Terminator cable was connected to the HA-1. This setup has proven to be great for testing source material and in this case, the capabilities of the Sonica DAC. The analog outputs from the Sonica DAC were connected directly to the analog inputs of the HA-1 headphone amplifier. This combination was more revealing to me than my main audio system simply because I can hear more fine detail without secondary reflections. My first impression was the low noise floor produced by the electronics. The audio reproduction was transparent with wonderfully smooth midrange and detailed upper frequencies. Bass was tight and well defined and I found myself becoming connected to the music with no fatigue from long listening sessions.
Some of the files that I downloaded for testing came from the The Nortic Sound website, which has high resolution test bench audio samples. These samples are available in various bit depths and sample rates.
Mainstream music services from TIDAL, Spotify, and Pandora also worked well, but there was some detection of compression when not using the higher bit rates. Still, I found that the sonic quality to be far superior than other configurations used with the same source material.
Sonica DAC is a great way to improve the sound quality of your system without a hefty price tag. The DAC was easy to set up and operate from the Sonica app. Music can be streamed from a variety of sources and in different ways with this DAC and the build quality is quite impressive. Oppo's Sonica DAC design leveraged heavily from the ES9038PRO SABRE DAC architecture and once again engineered a great sounding product that is easy to use.