S.M.S.L su-9 Dac

SMSL has a new DAC in it’s SU series. Priced at $439 and shipping out on the 29th, based on the ESS Sabre 9038PRO.

Specs and initial measurements look pretty good so far and inclusion of MQA and Blu-tooth are both welcome and there’s a nice selection of filters!

Most important tho is that so far I think it sounds pretty good! I settled on the Slow Linear filter and or Fast Hybrid Filters which sounded more natural in comparison to the Fast and Brickwall filters were a bit fatiguing. Shout out to the team at Apos Audio for getting this shipped out to me a bit early for review!


Reserved for the review I’ll have posted here shortly!

Just finished my review.

I meant to say this in the review but… this is a DAC that I would personally be completely fine with owning. There is still a difference between it and the X Sabre Pro, but it’s that type of sound.


Besides the Matrix, what other DACs do you use? I can’t recall.


Would you pair it with D8000 Pro?

I have a Taurus for the amp stage now, basically same same as the IHA6 balanced out.

Well, at the moment the Matrix is the go-to. Before that it was the D90 for a bit (community member sent it on loan), before that it was the Mytek Liberty, at one point it was the Fidelice DAC. But I specifically asked the guys to send the X sabre pro over again, so this is the second time I have it in, I like it that much. I’ve also got the Pro iDSD here in the background.


That’s a tough question. I’ll have to test it with the IHA-6 and the D8K Pro. I mean, the IHA-6 is overkill for the D8K Pro haha. But I suppose it’s still nice to use. Remind me to get back to you on that.

Overkill in power sure, but an Amp sounds how it sounds. Taurus sits at 15% for the D8000, Magnius 50%. But Taurus sure as shit sounds better to me.

That’d be good thanks. I like the value proposition of the SU-9 and features, but skeptical of the sound and synergy.

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If the Taurus has a touch of that “body” an warmth you get with Class A sometimes it should synergize well. SU-9 has some of that eSabre aggressiveness, defined texture and lean so a tiny touch of added warmth would go a long way imo.

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Yeah it does, a hint. Not super warm like a V281 or something though.

Question for you: If you set the SU-9 to a certain volume, I assume when you turn it off and on again it remembers that setting? But also importantly, is it smooth in doing that, or does it do that thing where a lot have a bit of a full volume blast before it defaults to whatever you set?

Thinking of having the Taurus on 50% or so (stupidly loud) and dialling it down with the DAC.

Taurus volume pot is a bit on its last legs atm

I don’t recommend adjusting the DAC’s output to compensate for the Taurus worn out VOL Pot… the output performance changes slightly with the output voltage.

Ideally I’d get your potentiometer repaired or replaced, I can’t imagine you’d be paying any more than $100 or so dollars for that kind of work. I think any worthwhile stereo or home theater sales/service shop locally should be able to do the work.

I ordered one online, $20. Will either put it in myself when it comes (probably take a month) or take it to a shop to stick in.


SU-9 has launched and it shipping now! It features a ESS 9038 Pro DAC chip along side Blutooth support all the way up to 192/24 with UAC and supports the more common LDac as well. What really impressed me the most with SU-9 isn’t so much it’s sound quality alone but the marriage of seamless functionality and sound quality.

I did my listening with both Windows via a Schiit Etir feeding Coaxial into SU-9 and with Android via USB. I ran SU-9 fully balanced into my Mjolnir Audio SRM 007tA with my Stax 009 and the ES Lab ES-1A. 009 is a faster BRIGHT headphone and ES-1A has a more rich weighty tonality, I also ran single ended into my Modded SET Amp with my HD 800 with my Bricasti M3 serving as an aboustle refferance.

The Pre-Amp stage works well and the volume knob is a bit soft but has well defined tactile notches. The USB works seamlessly with all my android devices, and LDac is smooth and gapless from my LGv20. I was also able to run MQA successfully thru USB Android Player Pro, tho I don’t believe that app fully supports SU-9 so hopefully soon that’ll be updated. The XLR and RCA outs also had a matched and consistent presentation with XLR being only marginally cleaner sounding.

What really impressed me were the implementation of the filters, Fast Hybrid and Slow Linear were the two I cycle’d between.

Fast Hybrid introduced a slight top end roll off which helped with music/masters/mixs that suffered from some excessive hotness in the top end it also created more cohesive staging. An I felt Slow Linear provided the most natural timbre/tonality with amazing texture and detail.

VS Schiit Modius & Modi

IMO, Modi and Modius sound very similar from their RCA Outs. Both have slightly forward but natural vocals, a rounder full presentation of low frequencies, cohesive staging but both struggle with congestion during busy passages. Modius XLR keeps a little of that harmonic richness and tonal naturalness, but doesn’t suffer from as much congestion nor the softness and lack of texture in low frequencies that plague Modi 3 and Modius RCA.

Frankly if you only need RCA Out I feel Modi 3 is enough. Spending an extra $100 for the marginal improvement Moduis has via it’s RCA’s isn’t worthwhile imo.

So SU-9 differs from Modius in that it

  • Presents a blacker deep stage
    • Sounds travel deeper in to the rear of the stage
    • The trailing end of sounds are more distinguishable from noise for longer and to quieter audible levels
  • Presents an Aggressive Envelope
    • The leading Edge of sounds are slightly emphasized
    • Thus it presents more discernable texture throughout the entire spectrum
      • So the rasp in violin strings, fret noise, the tactility of a piano
  • Vocals are a bit withdrawn
    • Tonally both spoken and sung word was a bit dry or lacking some harmonic richness
  • Staging was Disjointed for Some Mixs
    • Where Modius was more consistently cohesive but sometimes “congested” SU-9 was more consistently clear and discernable tho at times sound “jumped” out a bit un-naturally to my ears

What I like about SU-9 tho is the filters can make small adjustments to correct some of the vocal qualms I had or the staging, more importantly SU-9’s RCA and XLR’s carry an identical presentation with the XLR being only marginally clearer. So regardless of what your output you need the quality of sound is near identical.

An as much as I love Modius I only use it’s XLR outs as it’s RCA’s do NOT maintain the same clarity which is frustrating when you want to run multiple amps within a single system. So I appreciate the consistancy of SU-9s outputs and the freedom that lends.

SU-9 vs iFi Zen DAC

Tonally I find Zen Dac has a lot of richness and good extension on both ends. I was able to use the 4.4mm BAL out of Zen dac to Feed into my Stax System.

Overall SU-9 presents noticeably more detail and clarity, Zen Dac sounds a bit congested an almost sluggish in comparison. That said, I still LOVE Zen Dac as an All in One and enjoy daily when I’m editing pictures and working on my satellite station. Still I feel confident that owners of Zen Dac will appreciate SU-9’s added functionality and overall improvements to resolve and detail as a whole.

SU-9 vs RME ADi 2

Presentation wise these two differ, SU-9 has that slightly harder more aggressive edge that RME ADi 2 sometimes lacks.

However in terms of overall clarity and resolve, RME ADi 2 is still better.

  • It’s staging is blacker, larger with better depth, width and cohesion.
  • Tonality it’s more natural without any fatigue.
  • Transients response is more vivid and discernable

SU-9 doesn’t sound bad by any means in comparison. But there’s a level of nuance and detail that’s lacking, a few little things that simply aren’t discernable with SU-9 that are with RME ADi2. That and ADi 2’s parametric EQ is a powerful almost un-matched tool kit that you don’t often find on other dacs… filters go a long way in making small adjustments to envelope and presentation, but are NOT a replacement for EQ if you feel your system needs EQ.

Some of you may find RME ADi 2 to sound too soft and I’ve found it difficult to address that qualm while maintain ADi 2’s detail and overall nuance. That said, there’s a huge price gap here too, I could build an entire system with SU-9 that would sound better (imo) than RME ADi 2 using only it’s on board headphone out. Not to mention ADi 2 has no wireless support nor MQA.

Still, budget aside, if your not needing MQA or Blutooth support I feel ADI2 is the better DAC overall espically if your using “harder” more aggressive headphones.

Concluding Thoughts

I did receieve this unit from the Apos Audio team for review so to that end I encourage you guys always to shop small buisness especially one’s that price match!!! But overall I feel SU-9 is a great option on the market especially if you need it’s Wireless and MQA functionality, and even if your not using all it can do it’s clarity and overall presentation are excellent. It’s definitely something I’d consider end game worthy for many of you guys.


I have SMSL M500 - it makes sense to change for SU9?

what don’t you like about what you have?

My M500 - ver.1 SW1.5 HW1.2. There is no support of 32 bits, not supports 256 DSD. Installation of updating is possible only once - 2.01 I can’t establish. SMSL recommended to send to repair to the seller. The seller of HiFi Express - is ready to accept but I have to pay the cost of a parcel. Payment to delivery to the seller it is expensive - to buy SU-9))) cheaper
M500 suits me - to me 54 years everything wants to be in time. In the review it is told that SU 9 - analog of Matrix Pro is my dream, but to me is expensive. I ask to forgive, I write with PROMT Translator

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I may go a different direction with my setup and bluetooth plus a remote will be nice to have.

The SU-9 is available from Amazon and Apos Audio. I like to support small business but don’t know anything about Apos. It seems like they might be a factory outlet rather than local small business.

Anyone have experience with Apos?

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I have purchased from Apos and had a great experience I also have purchased from the sponsor of this forum Headphones.com and had great experience as well. I would purchase from either of them before Amazon if possible for audio gear. @NickZ


Thanks for the info. I’ll give them a try.

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Dear friend, Core Team. I haven’t understood the answer and I will repeat a question. I have SMSL M500 - it makes sense to change for SU9?