$301-400 DAC DAC's review Stoner Acoustics UDX Technology

Stoner Acoustics UDX DAC Review

Stoner Acoustics UDX

Disclaimer: The Stoner Acoustics UDX was despatched to us in change for our trustworthy opinion on this evaluate.

Many because of Stoner Acoustics for giving us this chance.

You’ll be able to examine earlier Stoner Acoustics merchandise reviewed on Headfonics right here.

I’ve by no means heard a Stoner Acoustics product earlier than, so when my inbox was primed with a pattern of their UDX DAC coming my approach, sufficed to say, I used to be very excited.  I’ve heard some good issues about this mannequin recently from different audiophiles and from a desktop area needy perspective, I can say that I’m very proud of that I acquired.

The UDX seems to be crafted in an aluminum chassis and a shiny black acrylic face-plate. For the dimensions, I might anticipate it might be very dense and weighted. However, it seems that the unit could be very mild feeling at 500grams.  That may be a good factor, for my part.  I truthfully don’t need issues to be ultra-dense at this worth level.

That is properly fitted to transportation and clearly as such with the included carrying case.  I don’t need to tote one thing very heavy and now have it lumber on my workplace desk.  I’d like to have the ability to swipe it gently to the aspect when not wanted.  It’s the little issues like this, that basically make me glad.

They might have simply weighted the unit with one thing additional however opted to not.  On this uncommon case, and in addition once more, because of the moveable nature of the gadget, lighter is best.  We’re at some extent on this construct high quality with this mannequin that a light-weight metallic body is all that’s wanted.  I can identify a number of a lot smaller amps and DAC’s that really feel considerably denser and needlessly hefty.

Stoner Acoustics UDX

The UDX presents a fast set up by way of a PC by means of a B-style USB cable.  You’ll be needing to obtain the USB Driver information off their web site.  Set up was fast and painless, fortunately, no errors.  Inside a couple of seconds, I used to be off to Foobar2000 to start listening.

The UDX presents balanced XLR 3pin in addition to RCA output.  That is nice information, a low finish of the center tier DAC with a totally balanced XLR output?  Sure, please! For the worth, this can be a steal.  True, I’d actually like a three.5mm output as properly, as a result of there are occasions once I need to join on to a speaker that has energy already that accepts a three.5mm enter.  Only a gripe there, for the worth I’m actually not complaining. Simply wishing.

Stoner Acoustics UDX

The UAC Change

Stoner Acoustics has carried out a cool change on the rear that allows you to swap manually for utilization with larger bitrate information.  The UAC-1 mode helps PCM 24bit/96kHz.  The UAC-2 mode helps 32/384kHz and in addition DSD64.

Okay, true that DSD64/128 is comparatively low, as increasingly moveable gamers are providing 128 and up. But in addition true, that I’ve one album in DSD above 64.  This actually doesn’t matter.  There are some free converters on the market when you have information that exceed this output.

It actually isn’t an enormous deal for me personally, nevertheless, I can see how that may have an effect on others who paid for a lot larger bitrate in DSD information.  That would pose an issue.  Once more, this can be a $330USD DAC with a balanced choice too, so I gained’t be complaining about this in any respect and DSD 64/128 is completely high-quality.  Appears greater than truthful to say nearly all of shoppers don’t personal information that intense anyway.

Stoner Acoustics UDX

Entrance Panel Guide Switches

The UDX is imposing, to say the very least and also you gained’t get anyplace with out studying the directions that include it, or what’s listed on their web site on how one can use the product.  You’ll see three buttons marked A, B, and C.  Every one operates a special perform and it might get just a little complicated should you don’t know what you’re doing.

Holding the C button will allow you to change between line out mode and preamp mode.

Whereas in preamp mode, the A and B buttons will toggle quantity up and down.

Tapping the C button regulates 7 totally different decay modes:

  1. A pointy roll off
  2. A sluggish roll off
  3. A brief delay with a pointy roll off
  4. A brief delay with a sluggish roll off
  5. A really sluggish roll off
  6. An enormous sluggish roll off
  7. Low dispersion.

Past that, the Mode mild will activate when you’re on the highest or lowest quantity setting however will keep yellow in case you are anyplace between the half-step attenuation’s which are dialed in.  That is accomplished this approach to permit for particular volumes that will probably be saved and remembered for whenever you flip the unit again on once more subsequent time.

That is nice information if you wish to hook as much as a speaker and have it begin out quantity at a selected place, or hook up with a greater amplifier.  In that case, you’d probably not have a lot of a scare with potential loudness points.  As long as you don’t set it excessive, I don’t see any points with a pre-saving perform for quantity.

Most of us are going to run by means of a a lot better amplifier and use the UDX as a pure DAC anyway, so odds are good that our speaker or headphone will probably be operating principally out of the amplifier within the chain which doubtless will probably be already set to a selected space on the dial that you’re snug with.

Stoner Acoustics UDX

I’m not keen on the AK44xx collection and that is the primary time I’ve heard the 4497EQ model of it.  After a bit of digging, I used to be solely actually capable of spot some Asian market manufacturers that additionally use this DAC, akin to SMSL and Gustard.

In all honesty, one of many newer era 90xx would have been a wiser selection for this mannequin.  We’ve sufficient impartial sounding DAC’s available on the market and I personally need one thing hotter.  However, that’s subjective and gained’t be factored into the evaluation objectively in any respect.  It’s simply necessary to notice that anybody who needs a heat, enjoyable and vivid heft to the sonic signature won’t be receiving that.  This DAC sounds impartial from prime to backside.


The UDX jogs my memory loads of the O2, which is regarded for its superb neutrality think about tonality.  So too, this UDX sounds similar to my older O2, with regard to tone solely.  I feel general constancy and purity feels extra broad and detailed although on this UDX.

The older era O2 feels thinner with a flat and absent EQ by means of the identical gear and the identical track.  It isn’t bloom or a sluggish decay.  It’s simply extra of a broad and enormous sense of low finish that appears to increase slightly deeper.  However, not a lot.

For what’s there when it comes to amount, I’m severely sad as a bass head.  Nevertheless, purists will adore it as they have a tendency to take pleasure in pure sounding gear.  I favor musicality and exaggeration.  Others favor flatness and a crystalline sort of expertise.


Oddly, the UDX feels reasonably positioned in bodily presentation.  It isn’t ahead and it isn’t recessed, which could be a good or dangerous factor relying on the way you take a look at it.  In my subjective opinion, I want one thing for my ears to latch onto and a completely flat expertise prime to backside, together with a reasonably distant really feel to area and vocals, is one thing I don’t take pleasure in. Nevertheless, a whole lot of customers once more on the market love a relaxed attraction and positively some tracks a well-tailored for that sort of sound.

In the best way of general constancy, the UDX is, once more, hyper-pure feeling and meshes very nicely with my Audeze LCD4 with that Euphoria within the combine. And in addition once more, not as good with the Heron 5 within the combine the place vocals appear a bit wonky and misplaced with such a pure sound coming via a vivid amplifier.

Stoner Acoustics UDX

Rig pairing

It’s all about rig pairing and matching the best approach.  The pure rig sounds unbelievable and even my customized screens from Empire Ears sound blazing quick with a really fast decay within the decrease mids space.  Male vocals sound sharp and razor-like in the easiest way.  It doesn’t hit exhausting, by sharp I imply very, very detailed and fast to decay.  This is a wonderful sounding midrange DAC.


This appears to be a standard development with the AK 44xx DAC choices of the previous few years.  The highest finish of this DAC sounds noticeably extra outstanding than the remainder of the spectrum as an entire.  In a not so destructive approach, the shift sounds unbalanced when it comes to amount.  Slightly lopsided in that regard however fortunately with some EQ you possibly can tone the highest finish down if that is a matter for you.

Brightness is just not the difficulty, it’s extra the treble can get scorching typically and that isn’t a fault of the DAC, it’s the fault of the monitor.  At regular volumes and with very pure gear, painful is a phrase I might use and that’s precisely what purists need. So, don’t take that as a nasty high quality.

Identical to the O2, the UDX additionally tends to be extraordinarily correct to the monitor.  Dangerous recordings sound horrible.  Nevertheless, pretty recordings with exceptionally incredible constancy will sound exceptionally incredible.  In purist gear, that’s what you need as a shopper who has by no means bought one earlier than, or that will not perceive tonality fairly but.

Do you take pleasure in true to the monitor sound? That is for you.  The UDX provides you with that as long as you pair with an amplifier that can also be pure sounding.

Treble Dynamics

As talked about, the highest finish can sound a bit slamming at occasions however that’s once more because of the monitor.  It sounds just about precisely the identical because the older O2 that I’ve and I couldn’t assume of a better praise.  Bodily and dynamic kick issue, or wince issue, is one thing that purist gear is unforgiving with and that’s the level completely.

If you would like a softer influence, then you’ll want to search particularly for a pure tone up prime, but in addition one with a bodily lessened dynamic slam.  They’re on the market, don’t fear.  So far as the UDX goes, it performs nicely with elegant sounding tracks in Jazz, for instance.  Piano key putting and really properly recorded guitars are eye-popping at occasions, however that sizzle issue just isn’t probably the most bodily slamming I’ve ever heard in a DAC, so don’t fear.

Issues can be effective in the event you personal an awesome impartial amplifier and set of headphones to pair with it.  Simply make sure that to not pair this with a heat sounding rig until you want a stepping stone…or should you require your heat rig to sound colder.  If that’s the case, then the UDX is a superb choice.


Aspect by aspect with my Oppo 205, that makes use of a 9038 chipset from a more moderen era, the UDX sounds equally deep sounding.  Regardless of that Oppo costing 4x the worth.  When it comes to width and peak, the UDX brandishes a suitable amount.  I’ve heard higher, however I’ve additionally heard a lot worse.  This doesn’t picture nicely in left to proper, however the depth of area and coherency is a robust level.

Realism issue could be very good and the picture itself feels intimate in that regard, nevertheless, that’s an odd distinction as a result of the truth that the midrange is a bit relaxed and never intimate.  If the void of the picture is comparatively average and never expansive, then I feel it must sound ahead within the midrange to compensate for that lack of expansive sound.

The UDX doesn’t supply that however the picture itself just isn’t actually missing objectively.  It is perhaps a factor that happens with purist sounding elements on this tier, however I can’t ensure.  Which means, the average tier of impartial sounding DAC’s are likely to make the most of elements that favor depth of area and coherency over an expansive sound.

Stoner Acoustics UDX



The UDX doesn’t mesh with my Heron 5 Strong State amplifier from Airist Audio.  That amp is simply too heat and vivid for utilization with a pure sort of sound.  Nevertheless, it sounds incredible with my Feliks Audio Euphoria tube amp and is the DAC I’ve stored related to it for that particular incredible meshing of elements.  A cheerful marriage of elements and elements is what we drive and attempt for on this interest and typically you find yourself discovering a very good one for you.

Sure, it’s true I actually don’t take pleasure in hyper-pure sound and tone.  However, as an goal reviewer, I do have to hold them round for comparisons and evaluation critiques sooner or later. Additionally, there are definitely a couple of albums I really like that sound higher with a completely pure vibe than they do with an exaggerated and heat sounding tonality.  For these situations, I revert to the Euphoria and UDX mixture.

Stoner Acoustics is absolutely taking this purity issue to the subsequent degree.  Outdoors of the O2, that is in all probability probably the most impartial sounding DAC I’ve ever examined.  So, purists, that is undoubtedly a mannequin you must adhere to.  The unit is cellular pleasant and could be powered simply off the USB, or via the included wall adapter.  It helps DSD and has a couple of guide choice modes for decay and roll off potentials.  That may be a pretty factor, certainly.  Past that, the imaging has a very intimate feeling.

The UDX is the kind of DAC that you simply hook up with your audio system via one other amplifier and also you overlook it’s there for years.  You overlook it’s there as a result of it simply works so properly.  It probably gained’t require updates or upgrades to a extra impartial DAC.  The DAC itself will stay greater than enough to be paired with the decrease finish of Hifi amplifiers, maybe, $700+ in pricing and much more.

As talked about, my Euphoria tube amp is nearly $2000usd and it sounds implausible with the UDX.  When you have a pure sounding set of audio system that have to be related to a PC, look no additional, particularly so if they’re powered-speakers.  You gained’t want an amp if they’ve XLR or RCA inputs on the speaker that may immediately hook up with the UDX.

  • Savitech SA9227 USB Audio Processor
  • AKM AK4497EQ Excessive-Efficiency DAC
  • Absolutely Regulated Digital and Analog Sections
  • Texas Devices OPA1611, OPA1612, OPA1632 Output Stage
  • Texas Devices ISO1540, ISO7640 Digital Isolation
  • USB Audio Class 1.zero PCM 24 Bit/96KHz
  • USB Audio Class 2.zero PCM 32 Bit/384KHz, DSD-64/128
  • zero.5 dB/Step Digital Attenuation
  • Choose-able Digital filters (7 settings)
  • One Pair of RCA (SINGLE ENDED) and XLR (Balanced) Outputs
  • Excessive Voltage Output 4Vrms (Balanced) 2Vrms (Single Ended) Line Output
  • THD(%): <zero.001% 20Hz-20KHz
  • Package deal Consists of:
  • Stoner Acoustics UDX
  • 1x USB 2.zero Cable
  • Carrying Pouch
  • 1x 1 Yr Restricted Guarantee

Elective Gadgets:

  • 1x Imply Nicely GS18U05-P1J Excessive-Efficiency 5V DC Adapter (Enter 100-240V, Output 5V three.00A)
  • Weight and Dimensions:
  • 152mm(Width) x 150mm(Size) x 44mm(Peak)
  • zero.5kg (UDX Solely)

Stoner Acoustics UDX DAC Review

four (80%) 1 vote


Construct Quality8.5



(perform(d, s, id)
var js, fjs=d.getElementsByTagName(s)[0];
if(d.getElementById(id)) return;
js=d.createElement(s); js.id=id;
fjs.parentNode.insertBefore(js, fjs);
(doc, ‘script’, ‘facebook-jssdk’));