Gustard X18 Review (Stereo DAC)

[gustard]

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.

Shenzhen Audio only accepted pre-orders before, all the X18 you can get were updated with new firmware, don't worry about this issue.

 

[Carlo2AC]

I love the look and design of these Gustard products!

hard to justify the X26 with how the X18 measures

 

[Music1969]

Another ESS 9038 PRO DAC chip based DAC - without ESS IMD 'hump'.

 

[gustard]

Gustard X18 Measurements
Let's start with our usual dashboard with balanced output with digital input adjusted by to get nominal 4 volt output:

You can get a better SINAD by setting volume to -2 dB on the machine's panel instead of your instrument. We integrated an analog attenuator which has better performance.

 

[Lero]

I think they will, soon.

Clock generator is snake oil or not?

 

[Carlo2AC]

@gustard any chance of we getting an updated or new A20H DAC-AMP combo with ESS 9038 Pro-Q2M or similar that measures as good as this?

 

[Lambda]

All the X18 you can buy now is updated with new firmware, don't worry about this issue.

Can user update there firmware?
How long will Gustard provide update support soft software/firmware?
Can the firmware source be released? if/before official support ends.

You can get a better SINAD by setting volume to -2 dB on the machine's panel instead of your instrument. We integrated an analog attenuator which has better performance.

So best Perfomrance is at 0dBS.
And lowering the volume is analog attenuation?

If so @amirm shuld differently repeat the test with 0dBFS and lowered volume.
This could make the difference between third and second place or maybe first place.

 

[Matias]

You can get a better SINAD by setting volume to -2 dB on the machine's panel instead of your instrument. We integrated an analog attenuator which has better performance.

Nice!

 

[gustard]

@gustard any chance of we getting an updated or new A20H DAC-AMP combo with ESS 9038 Pro-Q2M or similar that measures as good as this?

Good idea, we need an internal evaluation about such a project.

 

[gustard]

Can user update there firmware?
How long will Gustard provide update support soft software/firmware?
Can the firmware source be released? if/before official support ends.

All you can get are the updated batch.

 

[Lambda]

All you can get are the updated one.

This was not the question.

No software is ever perfect and you released faulty software in the past.
How can you make sure this won't happen again.

So the question is how to deal with it.

Can users update the there firmware?

How long will Gustard provide update support soft software/firmware?
Can the firmware source be released? if/before official support ends.

 

[Lero]

I love the look and design of these Gustard products!

hard to justify the X26 with how the X18 measures

X26 is now an old model i think, for the time it was gold.

 

[Atanasi]

I think they will, soon.

Is the rack also available for purchase?

 

[gustard]

This was not the question.

No software is ever perfect and you released faulty software in the past.
How can you make sure this won't happen again.

So the question is how to deal with it.

Can users update the there firmware?

How long will Gustard provide update support soft software/firmware?
Can the firmware source be released? if/before official support ends.

You are right bro, there's no 'perfect software', but we are always trying to do the best in development. Big bugs were killed before batch production.
Once new bugs noticed by users, we will keep tracking and solve it as soon as possible. All the firmware updates would be released and stored on Internet. This issue of X18 is noticed before batch productions' delivery, so everyone of you can buy the fixed one.

The support will last at least one year after production stopped.

 

[Mathias]

You can get a better SINAD by setting volume to -2 dB on the machine's panel instead of your instrument. We integrated an analog attenuator which has better performance.

Does this mean that the X18 can be used to drive a power amplifier without significant performance loss? Or is it recommended to use an analogue preamplifier?
Actually, the question is how good the X18 is as a preamplifier.

 

[Vhond]

So, this one is better than the X26 Pro?
X26 Pro succesor is about to come??

 

[Matias]

Comparing to the Topping D90SE, the Gustard X18 uses the same ESS 9038PRO (2 chips, 1 per channel, as D90SE uses only 1 chip), and the same 16 channels IV conversion using OPA1612 opamp, same bluetooth LDAC support, same MQA support, same 5V XLR output, same SINAD... Almost identical. D90SE 900 usd x 750 usd X18 though.

Which one came first and who copied who?

 

[anphex]

Hmmmmmmmmmmmmmmmmmmmm great DAC but I don't really see the point to pay about double 1,5x the price for slightly slightly better performance than the X16.

 

[Tks]

Wow! Looks like Gustard has listened to their customers. Bigger screen and on-off-button on the front. Nice!

It only took what? 3 years or more for that to happen?

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As for this DAC, this is the best THD vs FR ratio I've seen I think. It actually begins to to slope downward as frequency climbs, never seen that before.

 

[Lambda]

1,5x the price for slightly slightly better performance than the X16.

Normal diminishing returns... And also this one has analog attenuation build in. According to @gustard

So in theory it shuld have the same good performance over a wider output range and not only closes to 0dBFS.
Would be niche to test this claim @amirm.