Mini and mighty entry level DAC that will be more then enough for many!

5 Min no BS review of the SMSL SU-1

Love this device it was my 1st external DAC purchased in 2023, get ready for the blow by blow!

At $160 AUD inc GST the SMSL SU-1 DAC is an easy walk up start for anyone who is looking to get into the HiFI hobby, the SMSL SU-1 will work great in you’re big boy system if your looking to move away from the internal DAC in your AVR or streamer and just as happy in a desktop environment, this little DAC is a significant upgrade to any PC’s/ MAC internal DAC.

I picked up mine directly from SMSL in China as we regularly purchase items for the CI – Custom Installer side of the business so having a direct relationship with the supplier makes sense in this instance.

With that said I would recommend finding a local dealer or via Amazon for ease of return if required, local shipping is a fraction of the price of sending back a single unit to China.

Some Pics To Feast Your Eyes On

Here’s The Crux

Pros

Measurements show ‘SOTA – State Of The Art’ in the following

– Super Low noise
– Super Low Jitter
– Near perfect linearity
– USB input
— PCM up to 768 Khz / 32Bit sampling rate (Great if you would like to over sample using Roon, HQ Player etc)
— Supports up to DSD512 decoding
– Coax / Fibre are limited to 192 Khz /24 Bit (This is standard across all modern Coax/ Fibre interconnects)
– High quality Japanese components
– For those who still use MQA it’s also a decoder.
– Build Quality – Great!
– Value for money ratio is heavily weighted in favour of the SU 1 side of the scales

Cons

– Visually it’s not much to look at so if your looking for something to highlight your full stack system and take pride of place on stage front and centre to match the rest of your stack as a full sized component, the SU-1 isn’t going to meet that goal.
– Limited to RCA outputs, even though they have been shown as super clean with an ultra low noise floor there will be some users who wish to use balanced outputs to their pre-amps.
– Minimal feature set, there are no filters to play with, it’s basically what you see and hear is what you get.

Let’s move onto both my subjective and objective thoughts on the SMSL SU-1.

SMSL SU-1 the little DAC that could.

Listening and function testing was conducted on 2 systems my desktop Mini PC and a full stack HiFI component setup.

Desktop System Nearfield

– Velocity Host vPower Mini PC (Asrock AMD) > Output USB-C

– Input USB-C > SU-1

– SU-1 Output RCA L/R > Palmer Monicon passive controller

– Palmer Monicon passive controller XLR > Input Yamaha HS8 Self Powered Studio Monitors

Desktop Notes:

– When plugging the SU-1 into my desktop system directly via USB-C I could hear pops and other noise when switching between higher/ lower bandwidth (bit rate) recordings, initially i thought this may have been due to either tainted power coming from the PC or some sort of switching issue between higher bitrates creating noise in the circuit.

— moving to a dedicated PS and connecting to a WiiM Pro as source over Coax or Fibre removed the popping noise between tracks and it’s a better listening experience with no interference from the PC power in the circuit.

— This also meant minimal oversampling only up to 192 Khz.

Full Stack Component System 3m to the couch.

Round 1 Testing

– WiiM Pro Plus > Output Coax

– Input Coax > SU-1 > ‘Remaining links in the chain same as below’

Round 2 Testing

– Fiio SR11 Roon End Point > Output USB-C

– SU-1 > Input USB-C > Output RCA L/R

– Topping Pre90 input RCA L/R > Output RCA L/R

– 2 x Sony TA-N55ES bridged mono 300W P/C >

– SourcePoint 8 Stereo Pair Speakers

you can read a little more about the components on the Audiophile Reference System page.

Full Stack Notes Notes

I wish i had something to add here above and beyond the desktop setup, the sound was clean and clear with a great sound stage even sitting 3m away from the system, notes are crisp with lots of detail really great to listen to!

More info in the subjective section below.

Let’s Kick Off with the Objective

– The DAC performs very well overall surprisingly so, over and above many integrated DAC’s I’ve listened to.

— can this be measured?
Yes in a blind test you can clearly hear the difference between the SU-1 and the WiiM Pro internal DAC as 1 example.

— Furthermore measurements of the SU-1 have been done over at ASR – Audio Science Review landing the SU-1 in the excellent category for performance, noise floor and jitter.

Objectively what more can you ask for from a DAC at this price outperforming many more expensive DAC’s.

SMSL SU-1 landing in the excellent category @ ASR

– Hows Build quality
In 1 word – Great! for an item at this price point the aluminium case is sturdy and all the inputs/ outputs are firm to the touch.

– Power not included

A PS is not included in box only the USB-C cable, the SU-1 runs just fine over USB-C plugged directly into my Fiio SR11 Roon end point, If you are looking to keep power separate you can go for a clean GAN Switching power supply if you have one it’s not going to hurt but realistically it shouldn’t effect anything if you stick with a spare switching PS stolen borrowed from a tablet or an old Apple device used for iPhones/ iPads etc it only needs 5v 1.5 amps to run.

Just keep in mind when using a separate USB-C power supply this means you cant use the USB-C to connect to your streamer or PC as a source and will need to use Coax or Fibre to connect.

– Support
Email support was satisfactory even with the language barrier they reply in a timely manner and do their best to answer all questions.

Subjective anyone?

How does it sound?

– On my desktop near-field listening is excellent compared to the PC internal DAC

– sound stage is wider, this is also because it’s near-field and hard to hear anything past the Yamahas

– instruments are detailed with really good separation and everything remains clean as the volume go’s up

– There are some musical interactions that can push the DAC to its limits with separation but in all fairness this same track can bring mmm – ‘many much more’ expensive DAC’s to their knees with that said there may be other issues at play that i haven’t pinpointed when running the DAC directly from the PC.

— For experimentation on your existing system play Paloma Faith – ‘Only Love Can Hurt Like This!’ and turn up the volume, there are multiple crescendos through the track with many instrumental and vocal layers intersecting really pushing a system. Give it a run and shoot me an email via the contact form with your experience 🙂

Comparisons

Comparing to other DAC’s i have sitting around i couldn’t distinguish any noticeable difference in quality only the difference in type of DAC chip sound created which i’ll touch on.

SMSL SU-9 – ES9038PRO DAC Chip on par with quality sound and separation, the SU-9 feature set is much more expansive check out the review page linked.

You can read my full review on the link above.

Geshelli J2S – AKM 4499 DAC Chip + Sparkos SS2590 Pro – The sound difference here is more related to the smoother sound of the AKM 4499 + Sparkos Op-amps which add a little bit of intended distortion to the sound creating a slightly wider sound stage but due to the intentional distortion added by the discrete op-amps it means that in higher frequencies notes don’t sound as sharp around edges and in lower frequencies BASS seems less tight, it’s like putting a filter on changing the sound – think tubes.

It’s not a smear on the J2S + Sparkos at all it’s like having different flavours of chocolate, which do want to eat today? That’s the subjective part of the process understanding your likes, dislikes and how they effect your listening preferences.

SMSL SU-1 Final Thoughts

– It has a small core feature set that is sufficient for many if you just need a DAC and none of the other pre-amp features offered in many more expensive DAC’s
– if i had a reason to own 5 of these i would! – 😉 – well at least 2 so i have a backup if 1 dies, even today the SU-1 is available to purchase and is an excellent buy, how can you beat the SU-1 price vs performance value proposition!? – i’m not sure you can.
– I highly recommended the SU-1 as an entry level DAC that for many will be the only DAC they need.