S.M.S.L SU-1 MQA MQA-CD Audio Decoder AK4493S XU316 768kHz/32Bit DSD512 Hi-Res DAC

Short versionIf you are in the market for a high end DAC with clean, rich, spatially balanced sound, and thought you had to spend enough to buy a used car, look seriously at this unit.Long versionI wanted a high quality DAC to bring lossless source to an older but very high quality sound system. I did not want to spend over $2K on another DAC, as i had to many years ago. So researching various options in the $200-600 range, i stumbled across this little beauty. All i want is a DAC, no silly controls to "adjust" the sound, no amp, not multiple channels, and most definitely no Bluetooth (who needs more EMF radiation in their home ?)So i read the reviews, and decided to try it, if it was not up to the job, then it would go back. The specs seemed too good to be true for the price, but let's see anyway.Open the box, take it out, plug it in, set the USB interface to the clock speed of choice and let it rip. Wow ! very impressive. Sound is rich, spatial positioning is incredible, at points i can actually hear the piano keys being pressed spatially at different points across the keyboard. You can hear the string of a bass voile linger after the note, you can hear the damper touching the piano strings, this is 95-98% as good as my older and far too expensive DAC i have. Overall sound balance it excellent. I ran jazz, orchestral, chamber, solo instrumental, and solo vocal source material through it, all come out just the way they should and completely as well as my expensive DAC, you could swear you were in the studio during the recordings.For me this is everything i wanted in a DAC, simple to use, easy setup, incredible full rich sound, no widgets and dongles i don't need, no need for external power, no extra systems to go wrong. For others who want to fiddle with the sound, or play with widgets this will not be so fulfilling. This unit is small, has one tiny white LED to show the current source, so it fits right into a low key equipment environment. If you like your sound system to have lots of lights and cascading displays, this will disappoint, if you like clean simple interfaces, where the only important thing is the actual sound, you should find this DAC completely satisfying. Oh and other reviewers are right, let it run for some hours, and it will get richer.

I am not typically impressed with modern audio gear. It just doesn’t seem to compare with the great sound that we get from the vintage audio gear. That said, audio chip designers are coming up with some interesting products. And audio component designers are taking advantage.I wanted to improve the audio system connected to my multimedia workstation. The systems already has a pair of vintage RCA Minimus 7 speakers and more modern Lepai LP-2020A Class T amp. These are far from audiophile quality but, for their modest price and demur size, they do a credible job. Sadly, the same can’t said for my DAC. It doesn’t sound great and has become intermittent. It was time for a replacement.I read reviews of the S.M.S.L SU-1 MQA MQA-CD Audio Decoder. Reviewers and osers described it as “amazing." Since it sells for a very reasonable $85, it was worth the gamble so I bought it.After connecting it up to my PC and audio system I tested it with a number of high def audio files. It sounded quite good. Then, just for fun, I fed a DSD file into it. I expected noise because few DACs can handle DSD files. What I got instead was a DSD decode from the device. Apparently, the designers included DSD decode into the chip that runs the S.M.S.L SU-1 MQA MQA-CD Audio Decoder. Amazing!What was more amazing was what I heard when a started listening to “Billy Jean” on the Michael Jackson “Thriller” album. It is a DSD file mixed from the original master tape. The drum beats at the beginning of the song were so sharp, so clear that it literally startled me!Hats off to the designers of this inexpensive, amazing DAC!

Update: March 13, 2024 (previously 1 star rating, now I give it 5 star rating).After several exchange of messages between Leaudio seller and myself, it was suggested that I install SMSL SU-1 driver from smsl-audio.com official website, which I did. To my surprise that fixed my DAC! Now I am finally able listen to music from my PC sent to SU-1 by USB cable, which is connected to my SMSL A300 by RCA. It seems the driver installation to my Windows 10 fixed whatever issue I was having with SU-1 DAC. As result of this, I'm updating the previous 1-star rating to 5 stars. As for the sound quality from SU-1, as stated below, it's an improvement over my SMSL A300 amplifier by 15 - 20%, but more specifically, it is the sonic clarity and separation that are the most notable. Though a minimal audio improvement over my amplifier's internal DAC, the sound clarity and instrument separation are noteworthy, and for that I give a 5-star rating. Also, through this DAC, vocals seem to be slightly more forward and clearer.March 6, 2023, initial review, I gave it 1 star rating due to the DAC's failure after 10 days of use.Bought this SMSL SU-1 DAC in November 2023, but I couldn't use it since I didn't have a pair of RCA cables to connect it to my class D SMSL A300 amplifier that I purchased from Amazon at the same time. The DAC was on Black Friday sale, so I figured to try it with my new amplifier.Fast forward to Feb 2024, I finally ordered a pair of CESS 163-4i RCA cables, connected the DAC to my amplifier. The SMSL SU-1 DAC improved the quality by about 15% over my SMSL A300 internal DAC. I used the DAC on and off for about 10 days, then today it simply failed on me. It simply fell dead silent while playing a music file from my PC (PC to USB cable to SMSL SU-1 DAC to RCA cables to SMSL A300 amplifier).I tried another RCA port in the back of my SMSL A300 amplifier, but that too didn't work. The DAC simply does not work at all. I also tried powering down my amp completely, unplug RCA cables between the DAC and the amp, then powered both up again, and toggled between various input options in the DAC to no avail (USB, coaxile, and optical just in case the internal circuit's connectivity had glitched and that toggling among input sources might reset it).The source-light LED still functions on the DAC, but I get absolutely no audio signal going into my amplifier. Heck, I even rebooted my PC just to see if that may be causing an issue, but it was futile. After 2 hours of wrestling with the connections and toggling between input sources and settings, I gave up.Now I'm back to connecting my PC directly to my SMSL A300 amplifier by USB cable, which works fine. As far as SMSL SU-1 DAC is concerned, it was a decent DAC for the price (while it worked). However, the unit I got simply failed after about 10 days of usage.I'd instantly return it for a refund, but the Jan 31 deadline return date is closed, so sadly it's not an option for me. A good-sounding, affordable DAC with a high quality DAC chip, but in my case, I must have received a lemon, so quality control seems questionable. Maybe it's just bad luck on my part, but I still wouldn't recommend this DAC to anyone. You'd be better off to spend a bit more money on a high quality DAC with its own power supply built in.Update On March 11, 2024 I emailed with photo attachments of the failed SMSL SU-1 DAC to support@shenzhenaudio.com. According to their site, they'll honor their product warranty up to 6 months with either a repair, replacement, or refund if their product proves to be defective. Hopefully they'll reply in a timely manner with a resolution. As others may encounter a product failure after the Amazon's 30-day free return policy, I'll post further updates for reference.Update, March 11, 2024, 8 hours later, shenzhenaudio.com support staff replied my to my email, asked for the Amazon purchase invoice and order number. I forwarded them the necessary information.According to their reply, they'll forward my case to their Amazon Support Team. I hope this will be resolved asap as I'll need to either get a replacement DAC or get a refund and buy another DAC, so for now I'm stuck in a limbo with 70 bucks tied up in a failed DAC unit. For now I'm stuck to using the internal DAC of my SMSL A300 amplifier, which is quite ok, but I did like the somewhat improved audio fidelity of SMSL SU-1 DAC.Update March 12, 2024. Got a reply from Leaudio requesting detailed info on what's wrong with my SMSL SU-1 DAC. I forwarded an account of how it simply stopped working while playing music from my laptop connected to it by a USB. Also forwarded 3 photos of the DAC. Hope this matter will be dealt with either a refund, replacement, or repair soon, because at this point, the DAC is useless.