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

Bought this is on review recommendations. Just had an 1990s DAT player refurbished, brought back from the dead after it had spent thirty years in the garage, now it plays perfectly but it had a somewhat compressed sound. This DAC has one of the very latest/best chip sets usually found in units at ten times the price, the DAC in the DAT is thirty years old so could benefit from the latest tech to give it a boost. Some people think all DACs are the same but they are clearly not, a listening test shows this very clearly, just as all headphones don’t sound alike. I have six DACs, some are good, some are not so good and it does not always relate to cost. A have a Fosi which is ok as a headphone DAC and pre amp which is ok, warm sounding but lacking clarity, a Beyerdynamic slightly better but not enough for the additional cost, a Chord Mojo which is very good used between an ipad and twin rca cables to an amp, a Prozor for 5.1 sound from a modern tv to ancient analogue cinema amp which was very cheap but sounds great and now this which sounds brilliant, better than the Chord but at about a fifth of the price. A good DAC puts air and soundstage into the music, separates the instruments and gives clarity to bass and treble. This one has opened up the sound of this DAT player, giving a clearer sound, very pleased with the result for such a low cost item. Also as the DAT is optical cable and the CD player, also from the 90s, is coaxial digital, this unit can take both items and you can switch between them using the button on the front.

Like most people, my interest in sound devices and recordings is simply about getting as close as possible to the sound of a great performance of the music to which I listen. Bach, Bacharach, Basie, whatever. And this super little sound device constitutes very siginificant progress in that quest. Connected by USB to my PC it takes PCM and DSD files, converts them and sends an analogue signal to my desktop amp (Douk Audio T6). I listen to the output on Sony MDR 1 headphones. Like everyone with good new equipment I hear things differently and more clearly on recordings I have loved for years. Dynamics, attack and decay of notes, balance within ensembles, tonal nuance and so on. The S.M.S.L. SU-1 makes it all possible. Set up and operation are simplicity itself and the Roon music library/player connected immediately. (The only advisory I offer is to ensure you download and install the relevant driver to facilitate ASIO again easily done from the SMSL website) All this for a derisory price compared to regular hifi equipment. The only regret I have is that I now won't be trying out anything else for some time to come.

Generally flawless DAC although I find I need some bass EQ compared to other converters. So silent and with such high resolution that digital volume control can be used with absolutely zero subjective loss in quality. The issue with the XMOS USB controller is that it goes into a standby mode after 5 seconds of no signal, apparently a default intended for when the chip is used in dongles for mobile devices (i.e. phones) to save a watt or so of power draw (silly for desktop and general hifi applications), and when it 'wakes up' it misses the first half second or so of playback which can get REALLY annoying if you're browsing files. It can be fixed in Windows by installing an XMOS USB driver from the SMSL website (the DAC is otherwise plug-and-play with the default, fairly recent Windows driver), but you then have to edit an XML configuration file to enable "Always On" as an option in its control panel (it's fixed to "On When Needed" otherwise). Search for "XMOS driver settings for no cutoff/delay" on the Audio Science Review forum. *** Edit Dec. 2024 *** the latest XMOS driver from SMSL's site (released in the last month or two) now allows 'Always On' available in the control panel (it might even be the default, I can't remember if I had to change it ), so my criticism above no longer applies. ETA 2 - A general tip - this little box draws practically no power, maybe a watt or two - leave it powered on 24/7 and it will last. If you keep switching it on and off (power cycling it) there's a much higher chance it will fail.

This is a decoder (DAC) and pre-amp, of the best audio quality. Actually, it's astonishing. Technically there are better DACs, but you can probably only measure the difference with professional equipment. Audio Science Review concludes "SMSL cuts the functionality to the minimum many need, to have high quality conversion of digital to analog for multiple inputs. Performance is superb for the cost, as it provides full transparency to the source. It proves that performance requires great engineering skill, and not a ton of money. A lesson that I hope one day high-end audio companies and their customers appreciate." I have it linked to a Pi2Aes (re-clocker linked to a Pi NAS music server) for my digital music catalogue and Web Radio, including MQA tracks. There's no volume control, which I rather miss, but that is available from the next stage (amp), so it outputs a good 2v. I'd prefer balanced inputs/outputs, but with this performance, who cares? This replaced a much larger DAC with multiple inputs, with greater functionality and lower cost. Did I mention how small it was? Astonishing.

Brilliant piece of kit for an affordable price. Wanted to push CDs and it did just that. Really uncovers the sound. Soundstage has improved massively and high end has a nice shine to it. DACS are meant to be transparent and it does just that. For the price, you are getting a lot for the sound. Highly recommended. I currently have the output running into the AUX IN of a tube preamplifier to get some nice warmth and harmonics through the tubes that digital just doesn't have and I must say it does it brilliantly. Vocals pop forward with a warm tone and bass has a nice timbre to it. The Mids need some working. For this DAC, it's a must buy unless someone has the money to buy a more expensive one. Which by all means go for it.

The SMSL SU 1 is a well made and featured DAC. However, if you have a detailed system already this DAC can prove a bit too forward in the mid and upper frequencies. The bass is there but a bit on the lean side. So much so I have reverted back to my Khdas tone board that gives a lovely level presentation, detail, image and bass. I use my DAC via coax to spdif of my CD player.

While this worked it was one of the best DACs that I have used. I have used DACs which are very much more expensive than this. It provides loads of detail and a decent soundstage. It looks good and has all the inputs (USB, Coaxial and Optical). It even supports MQA if that is still of use. Why the poor rating? Well it just stopped working after a few weeks. A bit of research shows that although seemingly a reliable item there have been a few cases with a similar fault. There is even a guide online for a DIY repair. Sadly the company I purchased from would not replace the faulty item. Fair play to Amazon they organised a return and a very prompt refund. It is currently now more expensive than when I purchased so I will not be re-ordering. Would I recommend this? Yes, when it works it really is very good. But be very careful who you buy from.

Bought this item to be able to enjoy Blu-ray concerts and Blu-ray Pure Audio releases. Set up was simple and the sound quality that it reveals is exceptional to my ears. At the time of purchase they had a couple of damaged packaging units they were offering at £55, so this was a steal for me. For what I use it for it is superb.