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Gustard X18 Review (Stereo DAC)

Rate this DAC:

  • 1. Poor (headless panther)

    Votes: 7 2.9%
  • 2. Not terrible (postman panther)

    Votes: 2 0.8%
  • 3. Fine (happy panther)

    Votes: 21 8.7%
  • 4. Great (golfing panther)

    Votes: 211 87.6%

  • Total voters
    241

amirm

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This is a review and detailed measurements of the Gustard X18 Balanced USB DAC with Bluetooth. It was sent to me by their seller, Shenzhenaudio and costs US $749.

Gustard X18 Review Balanced Stereo USB DAC.jpg


As you see style is very much the same as other Gustard products. I like the high resolution display with larger volume indicator.

Back panel shows the usual connections:

Gustard X18 Review Bluetooth Balanced Stereo USB DAC.jpg


Gustard X18 Measurements
Let's start with our usual dashboard with balanced output with digital input adjusted by -2 dB to get nominal 4 volt output:
Gustard X18 Measurements Stereo USB DAC.png


That is extremely good performance. The second harmonic dominates distortion profile but it is down -135 dB (25 dB below threshold of hearing). This easily qualifies X18 as state-of-the-art, placing it in top 3 DACs ever measured:
Best stereo USB DAC.png


EDIT: post these measurements, the company advised that the X18 has a high performance post DAC attenuator and as such, performs better using its volume control than attenuating the input signal. So I tested that with volume set to -2:

Gustard X18 Measurements Volume -2 Stereo USB DAC.png


As you see, the attenuation is slightly less than making the same change in the source. I usually allow 0.1 volt variation but this is a bit much as far as fairness to other DACs. Still, going with it, the X18 changes position to #2 best DAC ever tested:
Top 20 stere DAC Reviewed.png



Switching to unbalanced RCA output, we still get superb performance:

Gustard X18 Measurements RCA Stereo USB DAC.png


Allowing the output to get up to 5.4 volt, we get even better performance due to increased dynamic range:
Gustard X18 Measurements THD+N vs Level Stereo USB DAC.png


Dynamic range is exceptional:
Gustard X18 Measurements DNR Stereo USB DAC.png


Intermodulation+noise performance is superb as expected:

Gustard X18 Measurements IMD Distortion Stereo USB DAC.png


Jitter test over USB is great:
Gustard X18 Measurements Jitter Stereo USB DAC.png


But there is some inconsequential jitter components if you use Toslink or Coax:

Gustard X18 Measurements Jitter Coax Toslink Stereo USB DAC.png


Linearity is nailed:
Gustard X18 Measurements Linearity Balanced Stereo USB DAC.png


As usual, you have an array of reconstruction filters to choose from:
Gustard X18 Measurements Filter Stereo USB DAC.png


Using default L-FAST, we get extremely clean wideband distortion+noise performance:

Gustard X18 Measurements THD+N vs frequency  Stereo USB DAC.png


Edit: forgot the multitone test initially:

Gustard X18 Measurements Multitone Stereo USB DAC.png


Conclusions
I live for happy days like this: another instrument grade, exceptionally well engineered audio product in the form of X18. It is clear a ton of effort has gone into providing full transparency to input signal. Yes, the cost is up there but if you want the best, you now have one more option.

It is my pleasure to recommend the Gustard X18 DAC.

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
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Azathoth

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Delicious, absolutely delectable. Where's the multitone test though?
 

Archsam

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I can't believe my beloved Matrix Audio Element X is not even in the top 10 anymore....
 

Koeitje

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Maybe its time for Gustard, SMSL or Topping to release something terrible, just to spice things up because right now its getting boring.
 

filo97s

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Now it would be nice to see if they release an "H18 headphone amp" to pair with this dac with this such superb performance.
Still, I think price for money X16+H16 are a better combo, you can buy both for almost the price of the single X18.
 

JSmith

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Great performance, nothing but transparent... just a shame there is no off by remote or a standby function, but good to see a power button on the front was included this time.


JSmith
 

Kuppenbender

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... just a shame there is no off by remote or a standby function,


JSmith
Maybe that‘s what the unlabelled button in front of the “menu” button does.
 

Χ Ξ Σ

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Buyer beware: Update your X18 with the latest firmware. If Gustard hasn't released anything, ask them for it.

@WolfX-700 measured this DAC a few days ago. https://www.l7audiolab.com/f/gustard-dac-x18/
While most of the usual tests yielded great results, the multitone test results saw significantly higher distortions than the SINAD number suggested, and they varied quite a bit depending on the different types of filter selected, including the default filter.

After this bug was communicated, Gustard quickly sent L7audiolab a different unit with updated firmware. The buggy multitone results were visible when the DAC was fed 0dBFS signal; therefore, Gustard decided to simply lower the level of the output voltage when the buggy filters were selected to prevent the signal every reaching 0dBFS. However, the non-buggy filters still gave the full voltage.

As a result, changing the filters literally changes the voltage by around 0.2Vrms, which could be audible. I found the way of fixing this bug kinda funny. Before the fix, you might not detect the distortions rising to -80dB. After the fix, you might actually detect the lower volume when switching to a different filter.

The fix and the new firmware were developed 3 days ago. Shenzhenaudio started selling the X18 DAC 7 days ago. This means all the units in stock still have the bug, including the one that Amir received. I am not sure how Gustard will handle this update. I suppose they could release a new firmware that customers can download and install on their own, but if that was the case, why did they have to physically send L7audiolab a different unit with the new firmware? Anyway, I hope Gustard will fix this bug for every customer and not just for a technical reviewer with an APx555B analyzer.

EDIT: Gustard replied very promptly later in this thread. All the units will have the latest firmware. You can buy the X18 with confidence!
 

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Dennis_FL

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Buyer beware: Update your X18 with the latest firmware. If Gustard hasn't released anything, ask them for it.
Not again !!!!! The X16 had firmware bugs and the problem is amplified by the lack of an easy way to do a firmware update. With the X16 you needed to purchase equipment to attach to an internal circuit board after disassembling the unit.

Why don't they run the above tests themselves so they can catch these bugs before releasing?

Update: See directly above....all new units have the firmware update
 
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