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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

Roland68

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I don't think you understand.
They put the I2S tuning on the U18 and they didn't put it on the X18.
Today practically all DACs already come with this adjustment in the setup.
Please don't be angry with me, but please have a look at what i2s is all about.
i2S is a more than 30 year old Philips interface exclusively for direct communication between ICs (on a circuit board) for the audio sector (i2S = Inter-IC Sound). This interface is built into most devices (DACs, CD players, and more) anyway, even if it is not brought out.
Here, however, i2S with LVDS (worldwide industrial standard for the transmission of Inter-IC communication over short cable routes) is used, which is converted accordingly in the transmitter and receiver.
That an HDMI cable is used for transmission is more of a coincidence, but above all it was available and cheap (plugs, sockets, cables). The transmitted signal has nothing to do with HDMI.

What do you mean by i2S tuning?
I had written that Gustard installed a galvanic separation for the USB area in the U18.
I also mentioned the improved and more accurate clock range. That's it!
And you can connect an even better clock generator (C18 $ 1599, -, but also others) to the U18.

The X18 (also applies to the A18) is already very well equipped.
The XMOS XU216 chip does a very good job in the U18 / X18 / A18 when converting USB to i2S.
And that is exactly the point, at this point, after the XU216, all i2S data is already available. The clock can be reprocessed, jitter / noise reduced or removed, but the data for the right and left channel (SD) are ready, as is the separation (WS) for it. The U18 can generate the master clock and make it available to the X18.
It remains to be seen whether this will make an audible difference.

I had 4 x devices with each XU208 and XU216 XMOS chip to try out (Gustard A18, Topping D70 / D70s, D90 / D90 MQA and a prototype).
There was an audible difference between the two XMOS versions for all devices. The XU216 chip brought a bit more resolution, better timing (clearly with "Passion and Pride") and simply more blackness in the background. But we're talking more about per mille than about percent.

Since the different devices sounded different (all very small distances), but the differences between the XU208 / 216 were all very similar, I assume that the XU216 is the real improvement.
I could imagine that the U18 can bring an advantage with DACs with other USB input chips or older XMOS chips.
Since the X18 uses the same XMOS XU216 chip (as does the U18), I am currently assuming similar improvements.

That's why I would first listen to whether the X18 has a sound improvement with the U18.
With the A18 with XU208 the improvement was audible with the U16, with the A18 with XU216 I didn't hear any improvement and even preferred the A18 solo via USB.
 

Reynaldo

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I agree with you.
But look at my example.
I used a Mac mini + Audirvana + X16 over USB, all OK.
I bought an SMSL SD-9 to replace the Mac Mini, when I use the I2S for DSD the channels are reversed. There is no way to solve this, because the X16 like the X18 has no I2S configuration.
Today virtually all new DACs have this feature.
That's just what I mean.
I don't want to get into this controversy if I2S has a difference to USB.
 

Reynaldo

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I didn't understand this Gustad warranty item for the X18. You need to buy the U18 for a two-year warranty, this is it?


Sem título-1.jpg
 
Last edited:

Roland68

Senior Member
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I agree with you.
But look at my example.
I used a Mac mini + Audirvana + X16 over USB, all OK.
I bought an SMSL SD-9 to replace the Mac Mini, when I use the I2S for DSD the channels are reversed. There is no way to solve this, because the X16 like the X18 has no I2S configuration.
Today virtually all new DACs have this feature.
That's just what I mean.
I don't want to get into this controversy if I2S has a difference to USB.
The problem with the swapped channels is probably due to the SD-9. Since it occurs not only with you and the X16, but also with other DACs, there seems to be an error. SMSL and Gustard are usually compatible with the i2S bus.
You can try to switch the i2S bus to inverted on the SD-9 (or vice versa). If you can manage that PCM and DSD behave the same, it doesn't matter if the channels are swapped. You simply swap the outputs on the DAC.

But that actually has nothing to do with what has been said before.
I also can't quite understand what they mean.

USB and i2S have nothing to do with each other. USB audio data streams (as well as optical, AES and SPDIF) are converted to i2S before processing in the DAC. Optical, AES and SPDIF can also be generated from this.

The U18 wouldn't change the problem, it's just a USB (input) interface with the usual outputs, i.e. exactly what is already integrated in the X18, only with the technical improvements listed.
You could only connect the U18 to the SD-9 via USB and then of course continue with the i2S in the X18.

However, I would not spend so much money to make up for a bug in another device.
 

Reynaldo

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The problem with the swapped channels is probably due to the SD-9. Since it occurs not only with you and the X16, but also with other DACs, there seems to be an error. SMSL and Gustard are usually compatible with the i2S bus.
You can try to switch the i2S bus to inverted on the SD-9 (or vice versa). If you can manage that PCM and DSD behave the same, it doesn't matter if the channels are swapped. You simply swap the outputs on the DAC.
With DACs that you have the I2S adjustment, the SD-9 works perfectly for DSD.
This is due to Gustard's I2S standard, and not being able to configure I2S on their DACs.
 

Reynaldo

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The U18 wouldn't change the problem, it's just a USB (input) interface with the usual outputs, i.e. exactly what is already integrated in the X18, only with the technical improvements listed.
You could only connect the U18 to the SD-9 via USB and then of course continue with the i2S in the X18.

However, I would not spend so much money to make up for a bug in another device.
I wouldn't spend money on it.
 

Reynaldo

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I left the X16 in its packaging, I'm not using it.
With Audirvana it's good, but with SD-9 I didn't like it.
I have other friends who had the same impression.

The Oppo 205 which has an excellent DAC, just for stereo shows.

To listen to music I'm using SD-9 by AES on my old Musical Fidelity M1 v2. It has a sound quality that I really like.

I'm too old for so many changes, I just want to listen to good music.
 

Roland68

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I left the X16 in its packaging, I'm not using it.
With Audirvana it's good, but with SD-9 I didn't like it.
I have other friends who had the same impression.

The Oppo 205 which has an excellent DAC, just for stereo shows.

To listen to music I'm using SD-9 by AES on my old Musical Fidelity M1 v2. It has a sound quality that I really like.

I'm too old for so many changes, I just want to listen to good music.
I also use Audirvana (almost) exclusively.
Did you ever run the X16 via AES or USB on the SD-9? How was that sound compared to your current solution?
If you have now found a configuration that you like, then that's good. I didn't want to argue with you either.

Actually, since the first USB interfaces / sources with i2S appeared, it has been the task of these devices to support the various standards (see e.g. Topping U90, Singxer, Matrix, Gustard etc.).
With the DACs, the manufacturer takes its standard or a widely used one. If you don't do that, you don't want compatibility or (time-consuming) tests.
At that time I had tested the X16 together with the A18 on 5 different USB audio interfaces and a Raspberry PI 4 (which is known to be a trick with i2S) with all formats via i2S. There were no problems with either of the Gustards. So far I have had the most stable and insensitive devices, which is why I kept the A18 as a work device.

But now back to the X18, which I'm really looking forward to, but I won't order it before someone posts pictures of the board.
 

Reynaldo

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But now back to the X18, which I'm really looking forward to, but I won't order it before someone posts pictures of the board.
Looking at the X18 manual, I don't see any advantage in buying the device for those who already have the X16.
For those who don't have the X16, it might be an option.
I think there are better options in the X18's price range.
 

kiyu

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Looking at the X18 manual, I don't see any advantage in buying the device for those who already have the X16.
For those who don't have the X16, it might be an option.
I think there are better options in the X18's price range.
same as Kitarist, which other options?
I am thinking: SMSL D1se, DO200
 

tw99

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I'm more curiosu how does Topping Pa5 perform against SMSL AO200 and similar amps in terms of sounstage as Class D amps are known to have much smaller soundstage.

“Known” ??? I think you are just perpetuating an audiophile trope here, there’s no actual evidence for such statements.
 
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Rover

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same as Kitarist, which other options?
I am thinking: SMSL D1se, DO200
Yes, they lose x18 in all respects.One has a bad SiNAD in the other an average dac.So far, x18 is the best.
 

kiyu

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Yes, they lose x18 in all respects.One has a bad SiNAD in the other an average dac.So far, x18 is the best.

Could you expand a bit your comments? or my first question would be, so sinad is the only that matters to you?
The only important part of the dac is the sinad?

is true that Do200 might go vs X16 because both use 2x 9068 ess.

d1se use 9038 pro, and the sinad is not as high but almost there 120 db vs 123? can you or any human reach that level?

d1se i2s is configurable and also has 10 different sound profiles or "sound colors" for me is something I would like to test. neither of those things are available in x18.
d1se is on the market for a while and so far no problems reported, which is also good.

First video review x18 already has some kind of incompatibility.. not so promising to be honest.

so again, what are "all aspects" that you mentioned?
 

Roland68

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Could you expand a bit your comments? or my first question would be, so sinad is the only that matters to you?
The only important part of the dac is the sinad?

is true that Do200 might go vs X16 because both use 2x 9068 ess.

d1se use 9038 pro, and the sinad is not as high but almost there 120 db vs 123? can you or any human reach that level?

d1se i2s is configurable and also has 10 different sound profiles or "sound colors" for me is something I would like to test. neither of those things are available in x18.
d1se is on the market for a while and so far no problems reported, which is also good.

First video review x18 already has some kind of incompatibility.. not so promising to be honest.

so again, what are "all aspects" that you mentioned?
The d1se is a good example of why I wouldn't buy a device without seeing the circuit board and layout.
The USB signal is drawn through the entire device, past the power supply unit to the XMOS chip on the other side of the board. It couldn't have been further away. The power supply for the display and processor must also cross somewhere. You have managed to perfectly place the XMOS chip between the display, Bluetooth module, processor and power supply, with the smallest possible distance.
But it doesn't work much better for the other digital inputs either.
Since the readings are good anyway, it may not matter that much.
 

kiyu

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d1se is on the market for a while and so far no problems reported, which is also good.
guys saying that i2s doesn't work on some units.. lol looks like was me :facepalm:
 

Roland68

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guys saying that i2s doesn't work on some units.. lol looks like was me :facepalm:
How can it be that SMSL does such a shameful layout with the d1se, and with the D1 they deliver an exemplary layout:facepalm:

Please post pictures of the X18 board ...
 
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