• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Gustard X16 Balanced MQA DAC Review

Gradius

Addicted to Fun and Learning
Joined
Aug 17, 2019
Messages
651
Likes
418
Location
Iquique, Chile

idkwho

Member
Joined
Nov 16, 2019
Messages
20
Likes
18
@gustard is there a reason why the analogue out specs state RCA output level is 2.0Vrms at 00dB Volume but in the review amirm puts the volume at -04dB volume to get 2.1Vrms? Why is the output level not 2Vrms at 00dB but 3.3Vrms instead? Is this the same with all production units?

Analog output performance:

Amplitude frequency response: 20-20kHz/+-0.08dB
DNR: >126dB
Crosstalk: -130dB@1kHz
THD+N: <0.00010% 1kHz
IMD: <0.0004%@-1dBFs
RCA Output level: 2Vrms VOLUME 00dB)
Output impedance 100 ohms
XLR Output level: 4Vrms(VOLUME 00dB)
Output impedance 300 ohms
 

Gradius

Addicted to Fun and Learning
Joined
Aug 17, 2019
Messages
651
Likes
418
Location
Iquique, Chile
@gustard is there a reason why the analogue out specs state RCA output level is 2.0Vrms at 00dB Volume but in the review amirm puts the volume at -04dB volume to get 2.1Vrms? Why is the output level not 2Vrms at 00dB but 3.3Vrms instead? Is this the same with all production units?

RCA should be +2V, while XLR is 2x of that, or +4V.

He mention the unit is capable of +3.3V @ 0dB (on RCA). Yes, is high.

While on XLR the max is +4.1V @ 0dB.

But it all has to do with noise, clipping, EMI, etc, more here:
https://www.audiosciencereview.com/forum/index.php?threads/2v-output-vs-4v-output.8119/

If you want SQ, just use XLR.
 
Last edited:

idkwho

Member
Joined
Nov 16, 2019
Messages
20
Likes
18
RCA should be +2V, while XLR is 2x of that, or +4V.

He mention the unit is capable of +3.3V @ 0dB (on RCA). Yes, is high.

While on XLR the max is +4.1V @ 0dB.

But it all has to do with noise, clipping, EMI, etc, more here:
https://www.audiosciencereview.com/forum/index.php?threads/2v-output-vs-4v-output.8119/

If you want SQ, just use XLR.

Yes this was my concern regarding the spec sheet -it mentions that RCA output is 2Vrms at 00dB volume which is incorrect as it actually outputs 3.3Vrms at 00dB volume.

This may cause clipping to those that do not know that it outputs 3.3Vrms instead of the 2Vrms as stated in the specs at 00dB volume. (The consumers that purchase this without seeing the review here on ASR).
 

Pdxwayne

Major Contributor
Joined
Sep 15, 2020
Messages
3,219
Likes
1,172
Could someone from Gustard please tell me what sort of DC offset I should expect at the output of the X16 during power off because I cannot use it direct with my amps, I get a MASSIVE shutdown thump that is very alarming for me and my woofers. I have measured the DC at the single ended outputs and it ranges from 300-900mv during a power down, one switch off managed just over 1v! Maybe this is ok with 99% of the amplifiers out there but my monoblocks are DC coupled, no capacitors on input or output but they have a DC servo. Im not looking for a work around here, I know how to work around it which for my wife isnt going to work, I just want confirmation that the unit is not faulty?
Alan
I want to know too, @gustard . I also plan to direct connect to amp and subs. Loud thump when turning off x16 is disappointing. This was the whole reason I wanted something other than KTB. KTB also gives out loud thump on and off.
 

A Surfer

Major Contributor
Joined
Jul 1, 2019
Messages
1,101
Likes
1,215
I am trying to determine what volume I should set the X16 to not overdrive my NAD M3's balanced input. I wish I knew what to look for in terms of input sensitivity. Here is everything that should be relevant taken directly from the M3's manual. Is anybody able to look this over and make a suggestion? I have always just left any DAC at 0.00dB but if that is over driving the M3 I would of course attenuate the output on the X16 to compensate. Any adive would be appreciated. See below for the specifications of my integrated. Thanks for looking.

PRE-AMP SECTION
Line level inputs
Input impedance (R+C) 150kΩ/500pF
Balanced Input impedance (R+C) 120kΩ/100pF
Input sensitivity, rated power 446mV
Frequency response (5Hz - 70kHz)1 <+/-0.3dB


POWER AMP SECTION
Continuous output power into 4/8Ω2 180W (23dBW)
Rated Distortion (THD 20Hz - 20kHz) 0.004%
Clipping power3 220W (23.4dbW)
IHF dynamic headroom at 4Ω +4.2dB
IHF dynamic power at 8Ω >280W (24.5dBW)
IHF dynamic power at 4Ω >480W (26.8dBW)
IHF dynamic power at 2Ω >785W (29.0dBW)
Damping factor (ref. 8Ω, 50Hz) >150
Input impedance 20kΩ / 680pF
Input Sensitivity (for rated power into 8Ω) 1.38V
Voltage gain 29dB
Frequency response; 20Hz-20kHz +/-0.03dB
Frequency response; at > 80kHz -3dB
Signal/noise ratio; ref 1W >107dB (AWTD)
Signal/noise ratio; ref rated power >130dB
 

Gradius

Addicted to Fun and Learning
Joined
Aug 17, 2019
Messages
651
Likes
418
Location
Iquique, Chile
And how do I know if the SHA is correct one?

Super simple, download both of them and check their SHA-1.

If you do that, you would know is: AFD54854004884AA86AB315444AF7FCADF5B06C5

For both of them (of course).

But isn't even necessary, as both are Digital Sign by Thesycon themselfs using SHA256, and are certified by DigiCert.

You cannot just fraud that.
 

Gradius

Addicted to Fun and Learning
Joined
Aug 17, 2019
Messages
651
Likes
418
Location
Iquique, Chile
Yes this was my concern regarding the spec sheet -it mentions that RCA output is 2Vrms at 00dB volume which is incorrect as it actually outputs 3.3Vrms at 00dB volume.

This may cause clipping to those that do not know that it outputs 3.3Vrms instead of the 2Vrms as stated in the specs at 00dB volume. (The consumers that purchase this without seeing the review here on ASR).

Well, if you really wants +2V, then a little mod is necessary, you would need this for each RCA port (Left & Right), see attached picture.

Cost: no more than $1 (four resistors). Of course, and some skills with soldering.

The calculator:
https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-voltage-divider
 

Attachments

  • resistor.jpg
    resistor.jpg
    57.9 KB · Views: 129

Pdxwayne

Major Contributor
Joined
Sep 15, 2020
Messages
3,219
Likes
1,172
Super simple, download both of them and check their SHA-1.

If you do that, you would know is: AFD54854004884AA86AB315444AF7FCADF5B06C5

For both of them (of course).

But isn't even necessary, as both are Digital Sign by Thesycon themselfs using SHA256, and are certified by DigiCert.

You cannot just fraud that.
You are missing my point. Without knowing anything about the original and all I have is a download from Chili, how do I even compare? What SHA do I compare? I need to have the original from manufacturer to get a SHA to compare, right? In that case, I might as well using the manufacturer download in the first place and not bother with the one from Chili.
 

Gradius

Addicted to Fun and Learning
Joined
Aug 17, 2019
Messages
651
Likes
418
Location
Iquique, Chile
You are missing my point. Without knowing anything about the original and all I have is a download from Chili, how do I even compare? What SHA do I compare? I need to have the original from manufacturer to get a SHA to compare, right? In that case, I might as well using the manufacturer download in the first place and not bother with the one from Chili.

You still don't understand.

They are digital signed AND certified ! How you would modified that? What's the problem if is from Chile, Mars or Pluto?

I did it for convenience, that's all. I repeat, they are digital signed AND certified.

Besides, in more than 35 years I never see anyone (black hacker or whatever) wanting to put a virus on a DAC driver before (that would be a first lol).

But yeah, you don't know me, I'm just the guy whom once patched those Pioneer DVR drives back in 2002~2005:
https://gradius.rpc1.org/

Thousands downloaded those modified firmwares from my site, zero complains, pure joy (lol).

Yeah, I was living in Brazil at that time. But enough with the offtopic.
 

Pdxwayne

Major Contributor
Joined
Sep 15, 2020
Messages
3,219
Likes
1,172
You still don't understand.

They are digital signed AND certified ! How you would modified that? What's the problem if is from Chile, Mars or Pluto?

I did it for convenience, that's all. I repeat, they are digital signed AND certified.

Besides, in more than 35 years I never see anyone (black hacker or whatever) wanting to put a virus on a DAC driver before (that would be a first lol).

But yeah, you don't know me, I'm just the guy whom once patched those Pioneer DVR drives back in 2002~2005:
https://gradius.rpc1.org/

Thousands downloaded those modified firmwares from my site, zero complains, pure joy (lol).

Yeah, I was living in Brazil at that time. But enough with the offtopic.
Again, for small files, I rather get from manufacturer. It is not like it will takes hours to download and I have to resort to download using non official sites to save time.
 

hmscott

Addicted to Fun and Learning
Joined
May 17, 2020
Messages
604
Likes
493
What I saw and heard from my X16:
I didn't hear any difference between PCM FILTER L-fast, M-slow, F-fast.
RCA and XLR work together, I have included two amplifiers.
NAD-3020 and NAD C370.My main one NAD-3020 with speakers Kenwood LS-505.
Bluetooth works fine for me.I played CD from my Marantz CD-65 mk2 which has a dac (tda 1541A and digital filter SAA 7220 P / B).
Marantz CD-65 mk2 there is also a coaxial output.I connected the Gustard X16 through it and turned on the NOS mode
on X16.I also played through Marantz's original dаc and Gustard x16.
There was a difference in the sound only when I turned off NOS MODE from X16.
When the X16's NOS MODE is ON, it cuts the high frequencies. And I don't like that.
If X16 is playing from my computer NOS MODE ON/OFF, I find no difference.
I guess it completely decodes the MQA.When I play through TIDAL, the display shows the (MQA. KHz ) in which the recording was made.
In TIDAL,MQA have files from 44.1KHz to 352.5KHz. Higher no have I seen.
Phase Invert (disable/enable) I still don't find a difference.DSD512 and SACD play normally in Foobar2000.
OPT and Coaxial also works normally.I haven't tried IIS and AES.
From volume, it can only decrease but not increase.
Thank you for the detailed firsthand feedback, is the X16 then an upgrade to you from your previous sound?, are you enjoying the x16 sound and x16 + MQA decoding sound?

Here are couple of playlists - I've not really spent too much time hunting for them, but after a few quests for high bit rate files I've gathered these:

MQA 352.8khz
https://tidal.com/browse/playlist/ce4bdd94-24e1-410f-bc72-6ac77cd949f9

MQA 192khz
https://tidal.com/browse/playlist/bd51ad45-df8a-4333-8615-d7526b80b70a

If you've found others please do share them. :)

BTW, I have a D90 MQA. I had been waiting for the Gustard A22 Dual AK4499EQ but the Topping D90 MQA / A90 came out first.

@gustard - I see APOS still lists the MQA option for the A22 - @gustard is the A22 MQA version still being worked on? Will it be released?
Gustard A22 DAC (Digital-to-Analog Converter) – Apos Audio

I see Gustard still has inventory of the AK4499, as Gustard is still releasing new hardware with the AKM chips. @gustard how much inventory for your AKM DAC's is still available? Will you sell out before AKM rebuilds and starts releasing AK4499EQ DAC chips again? I'm happily surprised to find new AKM DAC's still being listed for sale after the 2020 Holiday Season:

GUSTARD DAC-A18 AK4499 MQA DAC Bluetooth 5.0 LME49860*6 DSD Decoder — HiFiGo
Gustard A18 DAC (Digital-to-Analog Converter) – Apos Audio

And, @gustard are A18's still shipping with MQA included by default?
 
Last edited:

Pdxwayne

Major Contributor
Joined
Sep 15, 2020
Messages
3,219
Likes
1,172
I checked with Topping L30 and indeed x16 on and off have pretty loud noise.

Maybe, just maybe, when I get my replacement L30, I can place L30 between my x16 and my stereo amp and subs. That way I can turn off L30 first before turn on off x16.

Any other downsides of using L30 in between, other than losing xlr usage and a few dB less in transparency?
 

ABall

Senior Member
Forum Donor
Joined
Jan 5, 2020
Messages
329
Likes
159
Location
Reading (UK)
I am trying to determine what volume I should set the X16 to not overdrive my NAD M3's balanced input. I wish I knew what to look for in terms of input sensitivity. Here is everything that should be relevant taken directly from the M3's manual. Is anybody able to look this over and make a suggestion? I have always just left any DAC at 0.00dB but if that is over driving the M3 I would of course attenuate the output on the X16 to compensate. Any adive would be appreciated. See below for the specifications of my integrated. Thanks for looking.

PRE-AMP SECTION
Line level inputs
Input impedance (R+C) 150kΩ/500pF
Balanced Input impedance (R+C) 120kΩ/100pF
Input sensitivity, rated power 446mV
Frequency response (5Hz - 70kHz)1 <+/-0.3dB


POWER AMP SECTION
Continuous output power into 4/8Ω2 180W (23dBW)
Rated Distortion (THD 20Hz - 20kHz) 0.004%
Clipping power3 220W (23.4dbW)
IHF dynamic headroom at 4Ω +4.2dB
IHF dynamic power at 8Ω >280W (24.5dBW)
IHF dynamic power at 4Ω >480W (26.8dBW)
IHF dynamic power at 2Ω >785W (29.0dBW)
Damping factor (ref. 8Ω, 50Hz) >150
Input impedance 20kΩ / 680pF
Input Sensitivity (for rated power into 8Ω) 1.38V
Voltage gain 29dB
Frequency response; 20Hz-20kHz +/-0.03dB
Frequency response; at > 80kHz -3dB
Signal/noise ratio; ref 1W >107dB (AWTD)
Signal/noise ratio; ref rated power >130dB
I would say the input sensitivity is .446v for the pre and 1.2v for the power amp action. Does this device have a preamp bypass option, something Nad have done in the past to enable use of a higher end pre? Just odd it states 2 input sensitivities.
EDIT: The specs don't state single ended or balanced though, perhaps a quick email to Nad is in order. Personally I would leave the X16 at 0db as the Nad must have remote volume? Trust your ears, I know others have different thoughts on this but I bought the X16 for its excellent performance and this drops due to its digital volume control depending on how much you reduce the volume, of course there is a point where its deemed not possible to notice and depending on your ears/system you may never notice but it would niggle in the back of my head but thats just me. Dont forget though that music is not recorded at 0db, not that I have found in my collection anyway and you also have a volume control on the Nad so you have control over the input voltage. I would say the only time to worry about this is when an amp uses a cheap taper pot for volume and they have worse channel balance towards the lower end but I doubt Nad are using such a volume control...
 
Last edited:
Top Bottom