Synergy
Efficiency
Since this is a dedicated DAC, the limitations lie within the amplification and source side of efficiency. While using the RAWPro-DAC1 as intended, I kept the volume at maximum using the amplified unit to raise or lower volume levels.
Filter changes allowed for some fine-tuning within limitations, while Soundcolor was more prominent in changing what was heard.
Pairings
The RAWPro-DAC1 paired naturally with the SMSL RAW-HA1, providing excellent sound through the small Yamaha speakers.
It lacks enough power for hard-to-drive headphones such as the Horizon, which was mentioned in my review. This duo paired best with speakers and made for quality listening sessions when used in that manner, regardless of the source.
My preferred pairing was with an upcoming amplifier review. This amp provides plenty of power for the Horizon headphones to shine. Changing the Soundcolor option between Tube and Richness afforded the opportunity to “color” the sound a bit, but that wasn’t necessary.
Using the Oppo BDP-83 through Coaxial and then out to the Akai mini-system gave me an excellent chance to hear the excellent sonic characteristics of the older Oppo.
Bringing the two generations together made for excellent listening sessions, with the wonderful top end of the Oppo shining through.
Select Comparisons
SMSL RAW-DAC1
Features
The RAW-DAC1 is built around the AK4191+AK4499EX chipset, while the RAWPro-DAC1 uses ESS9039MSPRO chips. The RAW-DAC1 also carries the same (3rd gen) XMOS XU-316, supporting up to 32-bit/768kHz and DSD512, which is the same as the RAWPro-DAC1. Both support MQA and MQA-CD.
All of the other usual source options are present, including Bluetooth 5.1 with LDAC and aptX HD.
One interesting addition is an I²S input, which reduces jitter and utilizes a direct digital connection for more precise and transparent audio. XLR out is a plus, especially since its partner, the RAW-HA1, carries XLR in. This is just like the RAWPro-DAC1.
There’s a specially designed, built-in shielded power supply inside both, enhancing power efficiency and lowering the power consumption while keeping external noises to a minimum.
The 2 distinct display styles are on both, allowing you to choose Universal or Graphic, and the same clear, easy-to-use settings menu is underneath. I appreciated this new screen technology on the RAW series.
Design
The physical design of the SMSL RAW-DAC1 carries forward the familiar aesthetic of the RAW-HA1, sharing it with the RAWPro-DAC1 save for the color.
The plain black box (or silver of the PRO) can unassumingly fit into your system without bother. A tempered glass panel on the front houses the 2.33-inch display.
To the right of the display is the function knob used to adjust the volume and navigate the system menu. Keeping with the theme, both operate similarly.
The rear panel offers a comprehensive range of inputs and outputs, including both XLR and RCA output connections.
Featuring dual coaxial, dual optical (as opposed to single of each on the RAWPro-DAC1), USB-C, I²S, and Bluetooth help round out a full Monty of connectivity options. The RAWPro-DAC1 carries a USB-B, while the RAW-DAC1 doesn’t.
Both use the RC-8C remote. Even with the smaller screen, changing between settings is easy, especially if you choose the visual option of bitrate with larger numbers (universal setting).
The graphics setting adds in the source. The universal setting on the RAW-DAC1 is a bit different than the RAWPro-DAC1.
Performance
It could be said that SMSL is pretty good at what they do. It can also be said that they sometimes put models out quite quickly, hardly giving us time to enjoy the existing ones.
The SMSL RAW-DAC1 could be the current culmination, following the SU-X of all those machinations within the company. Keeping the DAC separate is always in the best interest of sound quality. And now we have the RAWPro-DAC1.
The RAW-DAC1 comes across as almost startlingly neutral in presentation, with a crystalline nature that presents a whole new aspect.
The clarity with which the music is presented through the various sources here is equally impressive, no matter the budgetary limitations of each option. The same holds for the RAWPro-DAC1, but with a smidge more clarity and detail retrieval.
That level of detail retrieval is savored mostly by higher-end DACs but is present in many. The RAW-DAC1 allows vocals to come through with a level of clarity they have no right to and carries forth a thoroughly engaging signature.
The RAWPro-DAC1 carries that forth with even better results using the ESS chips, which are known for their levels of clarity.
SMSL SU-X
Features
The new tech used in the SU-X carries “down” to the RAWPro-DAC1 with regards to the DAC chip, with both using the ESS9039MSPRO. The SU-X uses a dual setup versus the singular in the RAWPro-DAC1.
The dual chipset in the SU-X sits within a true dual-channel design that is fed by two large toroidal coils and several low-noise-regulated power supply stages.
Both use the SMSL proprietary multi-frequency CK-03 Jitter processing circuit stage to manage the timing and keep Jitter at zero.
The USB input stage on both uses the XMOS XU-316 true 32-bit USB solution, which seems to be a common solution nowadays but a successful one since it can easily handle high bit rates from a USB 2.0 port.
Design
The SMSL SU-X’s overall design is a robust one made from a thick sheet of aluminum and a thick sheet of tempered glass up front. Large metal fins occupy the side panels, and the overall package is a hefty 5.9 pounds or 2.7 kilograms, however, it does seem heavier to the senses.
Overall, the SU-X is larger and carries a larger footprint. The one worry I have about the SU-X is that the screen shows above the chassis, making for a problem if stacking is needed.
There is no getting around the good looks of the SU-X and its handsome cabinet with a sleek industrial design.
This comes across as more premium than the RAWPro-DAC1, but it also might draw unwanted attention to itself, whereas the RAWPro-DAC1 simply flows into a system.
Performance
The natural timbre of the SMSL SU-X is its best characteristic, and so is the RAWPro-DAC1. “It strikes a balance between smooth and ardent that presents the listener with quite an accurate translation of what’s in a recording,” according to Louis, and I agree.
Where the RAWPro-DAC1 emulates a little less smoothly, the focus is more on clarity. Here, the SU-X might win out a bit for those who prefer smoothness in character.
Both extract an alarmingly high amount of detail and do so successfully. High micro-dynamic levels represent a coherent manner of presentation in both.
The overall sonic signature is linear in frequency response and detail-rich, with the SU-X being slightly more detailed.
J.C. Acoustics UDP-5
Features
Many DAC/Amps have come through and gone back into the packaging after review. The J.C. Acoustics UDP-5 is the exception. It still occupies a VERY prominent place on my desktop and still sees regular usage.
The UDP-5 is a standalone midrange desktop DAC/headphone amplifier and uses two near-flagship ESS ES9039Q2M chips for decoding, as opposed to the ESS9039MSPRO in the dedicated RAWPro-DAC1.
The UDP-5 chips are also isolated from interference by placing them away from the FPGA core processor and the balanced amplifier circuits, much like the PRO.
Using a 16-core XMOS XU216 USB interface (a generation older than the RAWPro-DAC1), the UDP-5’s USB-C decoding supports high-resolution audio streams of up to DoP & Native DSD64-DSD512 and PCM of 16-32bit, up to 32K-768KHz, which is still the same in the SMSL.
Design
The UDP-5 carries the typical slim-height dimensions of desktop amplifiers with dimensions of 239*50*208mm (which is almost identical to the RAWPro-DAC1).
It weighs 3kg, or 50% heavier than the RAWPro-DAC1, most likely due to the amplification hardware. This falls right in line with its peers, but the design sets itself apart with many differences.
The large black volume knob dominates the front right, with two features described below. The matte black and plastic do not look out of place. On looks and operation of the volume knob, both are very similar. Both share a 3” IPS screen for viewing the submenus.
The script on the UDP-5 is smaller and harder to read, though, making the RAWPro-DAC1 easier to use across a room. That said, I found the lettering and choices to be easily readable from my desktop setup and easier than some alternative units that have larger lettering.
Aviation aluminum is finished with ceramic sandblasting on par with our Smartphone technology, showing the precision taken in construction. I would rate the looks and construction of the UDP-5 slightly ahead of the RAWPro-DAC1.
Performance
What I did not expect from the UDP-5 was for an ESS-chipped DAC to sound more like an AKM-chipped set than an ESS, which is known for a clean, clarity-driven sound.
The ESS-chipped UDP-5 comes across as musically smooth, without any of the potential pitfalls known, such as piercing highs or thinner note quality. In terms of smoothing the character, the UDP-5 is much mellower, with slightly less definition to the sound than the PRO.
I found the UDP-5 sounded organic without becoming too thick or slow across many listening platforms, including harder-to-drive headphones such as the ones I used. The RAWPro-DAC1 comes across as crystalline and crisp.
The UDP-5 proves you can have the best of both DAC/amp worlds with excellent sonic characteristics and gobs of power for your hard-to-drive headphones, while the RAWPro-DAC1 specializes in making the sound the best it can be. Both are worthy additions to the foray.
My Verdict
Coming off the SMSL RAW-DAC1 review, I was already impressed with the performance. Switching to an ESS-based DAC, the RAWPro-DAC1 proves its worth with a performance that backs up the choice.
With a level of detail that would make a college professor of statistics blush, the crystalline clarity carries over from the “lower” sibling RAW-DAC1 and then some.
The whole point of a quality DAC is to allow the sound performance to take center stage, and the RAWPro-DAC1 does so without encumbering the listener with unnecessary add-ons.
There is no need for additional treatment to the sound, but the Soundcolor implementation here allows the listener to fine-tune what is heard, matching the amplifier of choice better than the RAW DAC1, which was no slouch.
If there is a downside, it would be the overall lack of output options, but having XLR out more than makes up for that.
The SMSL RAWPro-DAC1 is a rare entry into the top-tier desktop audio world at a mid-tier price. As such, it has now gained a permanent seat within my system. I highly recommend a long listen if for nothing else, but to garner a view into a superb desktop DAC.
SMSL RAWPro-DAC1 Technical Specifications
- Input: USB /Optical/Coaxial/Bluetooth/I²S/AES/EBU
- Output: RCA/XLR
- Output Amplitude:
- XLR: 5.2Vrms
- RCA: 2.5Vrms
- Output Impedance: XLR: 100Ω RCA: 100Ω
- THD+N：XLR: 0.00005% (-125dB) (UN-WTD) RCA: 0.00007% (-123dB) (UN-WTD)
- Dynamic range: XLR: 132dB, RCA: 127dB
- SNR: XLR: 132dB, RCA: 127dB
- USB transmission: USB2.0 (asynchronization)
- USB compatibility:
- Windows 7 / 8 / 8.1 / 10 / 11 (Needs Driver)
- Mac OSX10.6 or higher、Linux (Driverless)
- MQA decoder: USB / Optical / Coaxial / AES/EBU
- MQA-CD decoder: Optical / Coaxial / AES/EBU
Sampling Rate & Bit Width
- USB / I²S: PCM 44.1~768kHz (32bit)
- USB / I²S: DSD 2.8224~22.5792MHz (1bit)
- Optical / Coaxial / AES / EBU PCM 44.1~192kHz (24bit)
- Optical / Coaxial / AES / EBU DoP DoP256 (USB), DoP64 (Optical/Coaxial)
- Bluetooth specification: 5.1 (supports SBC, AAC, aptX, aptX HD, LDAC)
- Power Consumption: <20W
- Standby power: <0.5W
- Size: 254 x 203 x 48mm (W x H x D)
- Weight: 1.9kg/4.19lbs
