Measurements of Gustard X26 Pro Dual 9038 Pro By L7Audiolab

[Rottmannash]

He's certainty joking.
As I said before, pick a glary (bad IMD) dac with bad linearity in the treble region, and you'll give yourself an unforgivingly bright dac

Pretty sure he's not joking.

 

[taner]

Hi to the owners of the X26 Pro, Taner, wannarock2, Red @ ...

after several weeks of use, do you have any comments to add on the positives and negatives

thanks for your comments

My experience on DACs may differ from others because I jumped from DIY and some other sub 100$ usb dongles to x26pro. So, my impressions may misguide the people with better experience. I'm a DIY guy and I know how dacs works in principle and how each circuit and chip differ from other.

My decision on x26pro is highly related with my DIY electronics experience because I can see that what Gustard engineers trying to accomplish with x26pro. Current output flagship dac chip (ESS Sabre), dual mono configuration, custom external filters and DSP, NOS mode, Class-A working principle, separate power rails and excellent measurements even with fully discrete analog section were the important selling points for me. I don't know any other manufacturer gathered all these things on same device.

I can put something on my behalf in this regard:

PROS:
* Sound. This dac changed my view on DACs because I started to listen recordings and experience the actual recording rather the device on the table. And I now understand better why serious listeners praise the old jazz recordings all the time. How can I tell.. those classic jazz recordings and vocals creates entirely different atmosphere in room. I can see that each artificial atmosphere differs by record to record, label to label, session to session. It is like putting another device on the table for each track. Vocals are my favorite part. They are so real and so attractive, this makes me pick the records with vocals in it. I begin to spend more time to listen to the music.

My power amplifier is a DIY Class-A amplifier thus my whole signal chain is Class-A. So my listening expressions may depend on this particular setup.

CONS:
* Some strange noise. When I directly connect the x26pro to the power amp or headphone amp, sometimes a noise appears on one channel. This noise sounds like a radio interference or a contact noise but not a hum. Noise disappears after recycling power. I admit that this issue is a bit discouraging which makes you check the setup at highest volume before each listening session. This issue may related with my setup and environment but I have to warn about this anyway.

* Heat. I'm actually not complaining about the heat because I know that you can't get away without heat if you prefer Class-A working principle. My only concern is 85*C rated audio-grade electrolytic caps which may have a shorter lifespan than much cooler case. Since they are top grade ones from Japan Nichicon, this may not be a big concern at all.

 

[pimy]

thank you Taner for your very interesting opinion

 

[Katji]

burn in?

Yes, burn in to stabilise it, to avoid burn out later.

 

[Veri]

Yes, burn in to stabilise it, to avoid burn out later.

My DACs can get a burn-out now, too?

 

[stumat]

I'm thinking of pairing my X26 Pro with the new Bluesound Node. I'm with Roon/Tidal/Qobuz. I also enjoy Radio Paradise.
Any owners have strong opinions on the wisdom of this?

 

[Krillin]

Heat and longevity
I own the Gustard X26 Pro. My advice is to be cautious if you don't own a 3d printer to create an external fan (I did). The DAC gets way too hot and will not survive in the long-term. The inside temps get at least 66°C and the capacitors are rated 85°C for 1000 hours. Heat is the enemy of transistor and capacitor longevity which is why vintage products like McIntosh last 40-50 years before needing a capacitor change. Also, not sure how all the heat affects the solder and modern PCB boards as it expands and contracts from heat over time. I will be sharing my 3d printed fan later for this DAC.

Class A is not the problem. Poor thermal management is the problem. Pictured is my custom heat management 3d print

Sonics
Sonically it's quite good. I can hear the difference between the filters Vivid and Gentle/Composite. However, I found it sounds best when using the PC to upsample to 384/768khz or 352.8/705.6khz when listening to 44.1khz. When comparing at 44.1khz and 48khz to my older 2014 McIntosh using Burr brown and cirrus logic chips the Gustard sounds noticeably more full. However, this McIntosh did not have a PCM1792A like other older McIntosh products. Compared to the McIntosh MHA150 which also uses a Sabre DAC the Gustard removes a bit of the edginess (classic ESS IMD hump?) but the increase in sonics is not worth it for the cost, very subtle and I would be very happy with the MHA150 DAC. I have only compared low bit rates.

Upsampling, filters and NOS mode
When upsampling to 352.8 khz+ everything is clearer/smoother and is most noticeable with 44.1khz and 48khz music. Also, when upsampling the DAC filters are no longer audible and I can hear no difference when NOS mode is enabled. NOS mode sounds horrible on lower sample rates (as it should). I found that while subtle upsampling 44.1khz to 352.8/705.6khz did sound better than upsampling to something divisible by 48khz.

DSD or PCM
I could only get Jriver to upsample to DSD256 (10.2Mhz). Whenever I tried DSD512 it stuttered which might be more of a problem with my laptop CPU struggling and not the DAC. Didn't sound too different than upsampled PCM and I couldn't reliably tell the two apart.

Headphones vs speakers
The Sennheiser HD650 headphones could not hold a candle to the Jamo R909 in detail retrieval and sound stage. A superior DAC didn't do much to improve the sound for headphones and upsampling was almost inaudible (unlike speakers which were very noticeable). I assume the pinna of the ear, superior high frequency performance of tweeters, and lower THD/IMD speakers plays a role here.

The Sennhieser HD650's have good THD performance but I believe modern speaker drivers outperform it. Like most headphones 10khz+ performance is bad or non-existent. According to Rtings.com measurements soundstage is not large due to the headphone not reacting with the pinna of the ear. Perhaps the HD800S might be a better choice as it reacts with the pinna much better, confirmed by measurements.

Jamo R909 open baffle speakers which used the best available DIY drivers at the time. Uses the Scanspeak Revelator 9700, same motor of the 9900 but has the dome of the 9500. Midrange is a modified version of the SEAS hexadyne W15CH001 for open baffle use, their top motor. The four 15-inch bass drivers are custom made for open baffle use, likely by BMS. Modern day SBAcoustics Satori, Illuminator or Purifi drivers are a tad better but when making a 3-4 way speaker these differences are minor or non-existent as drivers are used in their most linear band.

Amplification
Luxman CL-38, Luxman MA-88 tube monoblocks, and McIntosh MHA100 (used to own MHA150 too). I have tried all combinations along with the Gustard X26 pro acting as a preamplifier. The best combination was the Gustard directly driving the MA-88's or acting as a DAC into the MHA-100 with XLR cables. The lower "90dB or more" signal to noise ratio of the MA-88's did not in any way affect sound quality or detail retrieval. The greatest difference in sonics was upsampling PCM to high bitrates. DAC quality is audible whether using tubes or solid state however I am using top tier products.

My take away

• Top tier speakers are more revealing than headphones.
• The Gustard is no worse than other DAC's at 44.1khz and 48khz. Sounds excellent when upsampled.
• Upsampling sounds better but requires SOTA speakers in regards to THD/IMD/crossover quality
• DAC quality is likely a result of filters and upsampling as opposed to THD/SINAD.
• Careful attention to 44.1khz upsampling might be good for future measurements on audiosciencereview, DAC's which upsample 44.1khz to a frequency divisible by 44.1khz might be better. I could hear the difference.
• NOS mode sounds horrible unless upsampled very high. Sounds excellent when upsampled.
• Upsampling to very high frequencies shifts the noise to higher frequencies. Upsampling very high likely moved this noise beyond 20khz, I assume my Revelator tweeters could pick this up.
• A computer does a better job than the upsampler built into the DAC. I wonder if this is Gustard thing or a ESS Sabre thing, maybe DAC's are not completely solved when it comes to CPU power. After all my laptop seemed to have struggled.
• Tube amplifiers are revealing of DAC's despite their inferior SN ratio and THD. However, I assume this is only if your tube amplifier is engineered to be objectively pure with TOTL output transformers and not subjectively "tubey"

 

[Veri]

My take away

• Top tier speakers are more revealing than headphones.
• The Gustard is no worse than other DAC's at 44.1khz and 48khz. Sounds excellent when upsampled.
• Upsampling sounds better but requires SOTA speakers in regards to THD/IMD/crossover quality
• DAC quality is likely a result of filters and upsampling as opposed to THD/SINAD.
• Careful attention to 44.1khz upsampling might be good for future measurements on audiosciencereview, DAC's which upsample 44.1khz to a frequency divisible by 44.1khz might be better. I could hear the difference.
• NOS mode sounds horrible unless upsampled very high. Sounds excellent when upsampled.
• Upsampling to very high frequencies shifts the noise to higher frequencies. Upsampling very high likely moved this noise beyond 20khz, I assume my Revelator tweeters could pick this up.
• A computer does a better job than the upsampler built into the DAC. I wonder if this is Gustard thing or a ESS Sabre thing, maybe DAC's are not completely solved when it comes to CPU power. After all my laptop seemed to have struggled.
• Tube amplifiers are revealing of DAC's despite their inferior SN ratio and THD. However, I assume this is only if your tube amplifier is engineered to be objectively pure with TOTL output transformers and not subjectively "tubey"

My problems with your take-away:

• You are 100% positing that the internal oversampling is flawed and that upsampling on a laptop somehow makes everything better. Why would that be? I'd like to see some proof of that since it seems extremely implausible.
• "Careful attention to 44.1khz upsampling might be good for future measurements on audiosciencereview, DAC's which upsample 44.1khz to a frequency divisible by 44.1khz might be better." What? When internal oversampling happens it'll be source x some factor, and it will most definitely be divisible by the original rate. Not sure why you'd think otherwise.
• What is a "tube amplifier that is engineered to be objectively pure" ? That sounds like a strawman argument the likes of "your amplifier needs to be revealing enough to hear the differences I can personally hear". Again, it would be nice if you could prove any of your statements. As it is, this just reads like someone's personal thoughts, which is fine, I guess, but hardly conclusive evidence of anything.

 

[Krillin]

My problems with your take-away:

• You are 100% positing that the internal oversampling is flawed and that upsampling on a laptop somehow makes everything better. Why would that be? I'd like to see some proof of that since it seems extremely implausible.
• "Careful attention to 44.1khz upsampling might be good for future measurements on audiosciencereview, DAC's which upsample 44.1khz to a frequency divisible by 44.1khz might be better." What? When internal oversampling happens it'll be source x some factor, and it will most definitely be divisible by the original rate. Not sure why you'd think otherwise.
• What is a "tube amplifier that is engineered to be objectively pure" ? That sounds like a strawman argument the likes of "your amplifier needs to be revealing enough to hear the differences I can personally hear". Again, it would be nice if you could prove any of your statements. As it is, this just reads like someone's personal thoughts, which is fine, I guess, but hardly conclusive evidence of anything.

1) I'm saying that on the Gustard X26 Pro there is an audible difference when using the filters. If I lower the laptop or desktop computer to the source sample rate I can easily hear the differences when switching filters. When I upsample the filters no longer make an audible difference. If it's implausible I would love to see amirim do an in depth review and explore. Or perhaps WolfX-700 if he can get it back. I am curious too
2) Lack of experience. Reading this: https://www.mojo-audio.com/blog/dsd-vs-pcm-myth-vs-truth/ If it's BS then educate me. The author was mentioning something about quantization errors when converting sample rates.
3) I was referring to measurements. There are a lot of single ended amplifiers or amplifiers which measure so bad it looks like single ended. It wasn't snobbery. Some amplifiers measure bad and some measure good. Isn't that what measurements are for? To show that not everything is equal? To show where there is bad engineering? I did not say "unless you have a Luxman..." Just make sure it's well engineered

 

[RobS]

CONS:
* Some strange noise. When I directly connect the x26pro to the power amp or headphone amp, sometimes a noise appears on one channel. This noise sounds like a radio interference or a contact noise but not a hum. Noise disappears after recycling power. I admit that this issue is a bit discouraging which makes you check the setup at highest volume before each listening session. This issue may related with my setup and environment but I have to warn about this anyway.

Did you have the same noise with other DACs in the same chain?

 

[RobS]

snip

Killer speakers! Thanks for your review. Tube amplifiers can be more linear than solid state amps, and certainly more resolving.

What filter are you using when upsampling for best sonic results? And what software upsampler? I have Jriver Media Center and it has an option for SoX upsampler.

 

[Krillin]

I haven't tried SoX resampler in Jriver yet. Vivid sounds the most crisp but Gentle is smoother. I find Composite hard to differentiate from Gentle.

I listen to everything and this is not the song or genre I would recommend to hear the full potential of any DAC. When listening to "eminem love the way you lie" swapping the filter between gentle and vivid was audible on eminem's voice tone.

"Total Eclipse of the Heart" by Bonnie Tyler upsampled sounded great to me. Really showed me what my tweeters were capable of and the DAC did great.

 

[RobS]

I haven't tried SoX resampler in Jriver yet. Vivid sounds the most crisp but Gentle is smoother. I find Composite hard to differentiate from Gentle.

I listen to everything and this is not the song or genre I would recommend to hear the full potential of any DAC. When listening to "eminem love the way you lie" swapping the filter between gentle and vivid was audible on eminem's voice tone.

"Total Eclipse of the Heart" by Bonnie Tyler upsampled sounded great to me. Really showed me what my tweeters were capable of and the DAC did great.

Yeah filters make a big difference. I was just curious how you were upsampling cause maybe there's a better upsampler out there than what I'm using in Jriver. Quite a few people like having their DACs operate in NOS mode then run a custom filter in HQPlayer.

Shame Jamo no longer manufacturers huge open baffle speakers anymore. I'm looking into DIY a pair similar to what you have.

 

[linger63]

1) I'm saying that on the Gustard X26 Pro there is an audible difference when using the filters. If I lower the laptop or desktop computer to the source sample rate I can easily hear the differences when switching filters. When I upsample the filters no longer make an audible difference. If it's implausible I would love to see amirim do an in depth review and explore. Or perhaps WolfX-700 if he can get it back. I am curious too
2) Lack of experience. Reading this: https://www.mojo-audio.com/blog/dsd-vs-pcm-myth-vs-truth/ If it's BS then educate me. The author was mentioning something about quantization errors when converting sample rates.
3) I was referring to measurements. There are a lot of single ended amplifiers or amplifiers which measure so bad it looks like single ended. It wasn't snobbery. Some amplifiers measure bad and some measure good. Isn't that what measurements are for? To show that not everything is equal? To show where there is bad engineering? I did not say "unless you have a Luxman..." Just make sure it's well engineered

When you set the X26Pro to NOS so you can upsample via PC I believe that automatically disables the filters.
It was my understanding that they only work when the DAC is doing the OS.

Also WRT heat........
I have my X26 on the bottom shelf of my rack and have no excessive heat issues.
Your 2nd pic shows it on top a Pre?...........maybe that's a reason why yours gets so hot.

 

[Krillin]

I'm not sure if the filters are removed in NOS mode however I could not hear the filters whether NOS mode is on or off when above 352.8khz.

The tube preamplifier can get hot but still not as hot as the DAC. I don't turn both on at the same time and I never leave the DAC on top if the preamplifier is on. The DAC directly feeds the McIntosh or MA-88's most of the time. I could feel a noticeable difference between 73°F and 78°F in my house but eventually it will heat up after a few hours and get hotter and hotter regardless of the house temp. With the Noctua fan I put on it I can leave it 48hrs without turning off and it's still cool to the touch. Check the comments section of this review (https://soundnews.net/sources/dacs/gustard-x26-pro-dac-review/), someone took a thermal camera and found the inside to be 66°C (150°F) on the inside.

Dynamics of the DAC impress me and measurements prove it but that's something much harder to compare subjectively. Sonically it's great and I don't desire the Topping D90se but it needs some air as there is no way for the heat to escape without a fan. Please notice how low the vents are.

What programs are compatible with the Gustard drivers and can take exclusive controls of applications? The downloadable USB driver is the same for all Gustard DAC's. I have only tried Jriver so far but it doesn't seem to take exclusive control with the ASIO driver or with the WDM driver.

 

[Frgirard]

My problems with your take-away:

• You are 100% positing that the internal oversampling is flawed and that upsampling on a laptop somehow makes everything better. Why would that be? I'd like to see some proof of that since it seems extremely implausible.
• "Careful attention to 44.1khz upsampling might be good for future measurements on audiosciencereview, DAC's which upsample 44.1khz to a frequency divisible by 44.1khz might be better." What? When internal oversampling happens it'll be source x some factor, and it will most definitely be divisible by the original rate. Not sure why you'd think otherwise.
• What is a "tube amplifier that is engineered to be objectively pure" ? That sounds like a strawman argument the likes of "your amplifier needs to be revealing enough to hear the differences I can personally hear". Again, it would be nice if you could prove any of your statements. As it is, this just reads like someone's personal thoughts, which is fine, I guess, but hardly conclusive evidence of anything.

+1
Do not forget we are in the audiophile world.

 

[Krillin]

As promised here is the 3d printed fan part for the Gustard X26 Pro to keep thermals under control. If you don't have a 3d printer there are many 3d print services out there. Will likely work on the original X26 too.

https://www.thingiverse.com/thing:4897746

 

[FrankBRC2]

Good night,
I recently bought a gustard x26pro and am having problems with random audio gaps/cuts. Games, youtube, music players in general (FLAC or APE). It happens via USB or Toslink. The gustard is connected directly to my Yamaha HS8 speakers via XLR. Already tried by RCA, the problem also happens. DAC drivers are up to date, Windows 10 (PC desktop) is up to date. Uninstalled several programs that I thought were interfering, like antivirus, disabled some functions in Bios like WiFi, and BT. I used different USB cables. I've already connected the DAC to different outlets, in addition to the powerstrip. But to no avail. I tested another pair of Speakers.
Any tips?
Thanks.

 

[nerekan]

I have a problem with the dac x26pro
when playing dsd clicks, when playing psm a dull sound.
sometimes it helps 10-15 times to connect to disconnect the x26pro by usb, sometimes reinstalling the windows driver helps.
tried different players (foobar200, Aplayer etc), tried on different laptops.
PLEASE, HELP

 

[TK750]

I'm not sure if the filters are removed in NOS mode however I could not hear the filters whether NOS mode is on or off when above 352.8khz.

The tube preamplifier can get hot but still not as hot as the DAC. I don't turn both on at the same time and I never leave the DAC on top if the preamplifier is on. The DAC directly feeds the McIntosh or MA-88's most of the time. I could feel a noticeable difference between 73°F and 78°F in my house but eventually it will heat up after a few hours and get hotter and hotter regardless of the house temp. With the Noctua fan I put on it I can leave it 48hrs without turning off and it's still cool to the touch. Check the comments section of this review (https://soundnews.net/sources/dacs/gustard-x26-pro-dac-review/), someone took a thermal camera and found the inside to be 66°C (150°F) on the inside.

Dynamics of the DAC impress me and measurements prove it but that's something much harder to compare subjectively. Sonically it's great and I don't desire the Topping D90se but it needs some air as there is no way for the heat to escape without a fan. Please notice how low the vents are.

What programs are compatible with the Gustard drivers and can take exclusive controls of applications? The downloadable USB driver is the same for all Gustard DAC's. I have only tried Jriver so far but it doesn't seem to take exclusive control with the ASIO driver or with the WDM driver.

Had a quick look at that comment section, may I ask why you consider those temperatures to be too high? Assuming those measurements are accurate, 45 degrees surface and 66 inside are warm but seem totally reasonable to me?