GUSTARD DAC-R26 Balanced Decoder R2R+1Bit Dual Native Decoding Music Bridge

[OhHeyItsLou]

Is there anything in particular you find good about that cable or is it just the one you use?

The pure silver conductors offer more detail without the brightness/harshness that silver is typically is associated with. I noticed an immediate improvement in low end both sub-bass & mid-bass. The EMI filtering is outstanding, darker background enhancing detail/clarity. I think the fact that the power and signal lines are separated helps with this as well. I'm including the description from the website, pretty fascinating.

"The TUBULUS Concentus USB Cable is based on pure silver conductors. These are semi-solid concentric conductors to minimize strand interaction, which is a major source of distortion.

The conductors are surrounded by mainly air, because (next to a vacuum) air is the best dielectric.

With a special thermo-process the silver conductors are restructured at a molecular level to reach a quality close to mono crystal silver. The conductors are also twisted with a high twist rate for the purposes of minimizing electromagnetic interference (EMI).

To preserve signal integrity the power conductors are physically separated from the audio conductors. With this construction there are 4 layers of shielding separating the power and audio conductors.

To prevent radio frequency interference (RFI) from modulating the ground reference skin effect filtering is applied to the shield. This is a very effective way to eliminate noise and RFI before it reaches the component.

The cable is finished with shielded plugs which are soldered with silver containing solder. All this makes it an unique usb cable.

The TUBULUS Concentus USB Cable is also available as a dual head version, which has separate usb-a plugs for power and audio.

TUBULUS Concentus USB cables are hand crafted with love, expertise and devotion with no excess decoration or luxury packaging and therefore true value for your money!

WHY BUY A TUBULUS USB CABLE?
A high end USB cable may sound like nonsense. After all it’s just 1’s and 0’s it has to transport. Any USB cable can do that. But those 1’s and 0’s have to be transported by a bunch of electrons traveling through a wire and electrons don’t know if they are ‘analog’ or ‘digital’. In fact, all electrical signals are analogue.

However, the digital signal is different; it is a pulse train, a square wave instead of a sine. But a perfect square wave doesn’t exist, because transition from one to zero requires time. So there is always a rise/fall time and the edges of the square wave will be rounded. In fact the square wave is a kind of trapezium with rounded edges.

Depending on the quality of the cable, the corners of the square wave will round off to a greater or lesser degree and the “flat” portions of the wave will become uneven as well. Small changes will make it harder for the receiver to detect the exact moment the rise or fall is happening. This will induce jitter. And if the changes become too big, the receiver will not even be able to reconstruct the logical 1’s and 0’s properly.

This is why a high quality USB cable like the TUBULUS Concentus can make great improvements in sound quality."

 

[m-i-c-k-e-y]

Tubulus Concentus line of cables are high on my list.

 

[Jake2]

I will offer my experiences here as an alternative and highlight these are just my opinions. I am in no way challenging anyone else's experiences etc, we all hear differently, listen with different gear and probably value some aspects more than others. Whatever you are happy with, enjoy it and ignore me.

I love reading about how other people experience the same equipment I own and if I can find a way to improve things from reading their impressions, then I am delighted. I don't think anything is snake oil and I never believe in anything that is being overhyped. I like to listen with my ears and then decide. Like everyone, sometimes I hear gains where no one else does and that's cool if people don't see it that way. I also sometimes think people are mad for what they feel are pluses they hear, but I will always be respectful of our differences.

I have tried the R26 with all of the sources I have or had while I have owned it. I think I would probably be described as "obsessive" by my audio friends when it comes to trying every possible combination available with any piece of gear I own. I am sure some of you can connect with that. If there is 1% extra available, I will chase it. Not blindly, but because I like doing it. It is a journey with your equipment and I find the best equipment has these hidden percentages. The best equipment is often over-engineered so you can tap into that. Crap gear is always crap gear no matter what the chasing.

My usual set-up is a Macbook Air connected to the R26 via an AudioQuest Cinamon USB cable. I have tried all the Audioquest USB cables but that is a discussion for another thread. I have found the Mac USB post to be as close to silent as I can find, even if charging.

I have tried I2S with some other DACs I've owned and found it to be vastly superior to USB, without the use of an external clock or DDC. I was expecting R26 to be the same.

This has not been the case with my R26 though. My experience with R26 is that USB is the best input, to my ears and equipment. When I listened to the R26 connected via (another) AudioQuest mini HDMI to Full HDMI cable with the Cayin N8ii as the host, I found it sounded inferior to the USB connection. I have used the Cayin N8ii with other DACs in this config and found it excellent so I would generally not doubt it set up like this. I have extensively A/B tested the N8ii's USB C output vs the I2S output too, to the best I can so I feel like I have good experience here.

Figuring it may just be a mismatch of items in the chain, I connected my Mac to the R26 via a number of DDCs, with and without inbuilt clocks, and my experience has been that at best, this config only brings the I2S connection up to the same standard as the USB cable (I have a sympathetic audio dealer who let me try a number of DDCs including the Singer Su-6, Musician Pisces, Topping U90 and the SMSL PO100Pro plus some others he recommended but their names escape me now).

After watching a well-known YouTube reviewer claim that he found the optical input to be the best, I went down the rabbit hole of connecting optical cables to all the sources I have, including some DDCs, and I found it to be marginally worse than USB but I really can't be sure because of the time it takes to swap from one source to the other and relying on audio memory. I tried everything from cheap optical cables I bought in a supermarket to "audiophile" cables which claimed to be better somehow.

Just to note, I don't buy into this BS but I am stupid enough to buy them to try out.

I don't know if better or different gear would return different results but I can just tell you that I am very happy with a USB C to USB B cable from AudioQuest connected directly to my Mac.

I also have a collection of USB C cables that all claim to be better in some way than others. As I said above, I am stupid enough to buy them, if only to test out their claims. While some are clearly better than others (not 400 euros better btw!), it will probably come as no shock to everyone (or maybe it will), that the most important thing is the quality of the USB port on your source. You can add whatever cables, DDCs, clocks or silencers you like but if the USB port is poor quality, nothing will improve it.

Some thoughts on the USB ports (if it is of any help to anyone):

- I have yet to find a standard Windows PC or laptop that has a USB port that is free from some sort of noise. You might think you have one but I would wager you just haven't heard a silent port yet.
- I have yet to find an audio card that can work with Linux and output high res files without some sort of degradation. I love Linux but it is really crap for Audio (if someone knows a distribution/ hardware combo that isn't crap, please let me know).
- Only USB C port iPads are worth considering as a source but they all somehow sound bright, especially the Pro models
- Lots of higher-end Android phones with UAPP sound very high quality. It is only when directly compared to a better source that they fall down. Don't compare and you will be happy!
- Macs offer the best USB ports IMO. They just work and are quiet. I am sure I will get hate for that, but for me, that is what I have found. I am not an Apple lover, I just buy gear that will produce the best results for my ears. If Windows works for you - brilliant. I am not running anything down and nor do I want to get into a debate. It is just my thoughts. Feel free to disagree and I will listen.

I haven't bought into changing fuses. Yet. I don't see why it is considered snake oil though. Every other part of the circuit that carries current we are happy to believe changes the sound. Just read my impressions above! If a fuse can change the sound positively, I am all for it. I just wish some of the manufacturers would put them up for independent scrutiny without the need to buy first. I would be happy to compare with other parts in the power train to see if they compare favourably. I am not sure I am happy to pay 200 euros for a fuse though without someone else testing it first, independently.

I am much more biased to believe something will sound better if I have spent my own money on it. I think these products need to be provided free to people with a track record of being impartial in their reviews etc.

While I am not immune to the effect that comes with spending your own money on something, I can accept if I have wasted my money. I am also happy to have tried something new and ruled it out though so I never feel completely conned if something doesn't work out. I don't think this is common in the hobby though. People seem willing to die on the cross for something they have purchased themselves and believe improves things. That doesn't lead to very impartial views of something like fuses. It needs to be tested back to back with the same source. One with the upgraded fuse, one without and using something like an Oriolus Audio selector so changes from one source to the other are instant and not relying on audio memory, which is grossly inaccurate, and most times biased. I also believe this has to be done on a source-by-source basis. If a fuse is good with one piece of equipment, it doesn't mean it will be good with all.

Personally, I think if you add an external piece of equipment to the chain and that improves things, you shouldn't commend the new piece of equipment, you should ask yourself why you bought something that needed more money being spent to sound good/ better. When you spent the money, was it actually better or did you just tell yourself that? Without testing as I described above with the audio selector, you are probably fooling yourself. You may think this is a crazy statement but I would suggest you put it to the test if you do. Differences we tell ourselves are there, often are not when you can a/b with as few variables as possible. I've had my bubble burst more than once in blind tests.

Buy at the price point you can afford and enjoy it. Even if a fuse improves things, you will just get used to it quickly and the improved sound becomes your new norm. You will get bored of it and not long after you will be looking at external clocks etc. It never ends. When you get to the end of that road it will be the R27 or whatever is next.

To wrap up and stop rambling, the Gustard R26 is one of the best DACs I have heard at any price point. It is really good. A solid recommendation from me with or without any mods and a comparative bargain. Just my honest thoughts above which I hope help someone. Cheers!

Nice write-up thanks. Excellent to hear you’re enjoying the R26 so much and thanks for sharing your experiences and preferred input. I too find it it really interesting reading of others’ different preferences, makes me challenge or check my own setup - which I’ve done and shared my observations below FWIW.

The pure silver conductors offer more detail without the brightness/harshness that silver is typically is associated with. I noticed an immediate improvement in low end both sub-bass & mid-bass. The EMI filtering is outstanding, darker background enhancing detail/clarity. I think the fact that the power and signal lines are separated helps with this as well. I'm including the description from the website, pretty fascinating.

I have a pure silver handmade USB cable with some similarities to your Tubulus, if not quite as sophisticated or as expensive (I’ve also heard very good things about the Concentus IIS btw). The Gothic Audio Semperfi Outsider also puts the +5v power line on the exterior of the two layers of shielding of the signal and ground core cables.

https://gothicaudio.com/collections...-usb-cable-type-a-to-b?variant=32016533979194

I got it based on strong recommendations in another thread. It was certainly an immediate clear jump in performance over the silver plated high purity copper USB cable I used till then between the Zen Stream and the Gustard U18. https://www.aliexpress.com/item/32812730357.html

Your and @armstrj2 ’s comments prompted me to dust off the SemperFi cable and give it another whirl direct from my Mac Mini M1 to the R26. It didn’t take long to confirm my preference hadn’t changed and is similar to @Forgisound . I prefer the R26 direct ethernet connection in my setup - Roon/HQplayer NAA, LHY SW-8 and Netgear switches in series, OCK-1 clocking R26, basic cat 5/6 UTP cables, and recently a Puritan power conditioner & Quartz Acoustics grounding boxes (other gear per sig).

The R26 internal streamer in my system now projects a deep and wide soundstage with a beautiful organic feel especially apparent with vocals that are textured and sweet with no rough or sharp edges, along with lots of subtle acoustic clues of note decay and reverberation in a space. There‘s great spatial and dynamic separation and layering that is maintained even then things get really busy. In contrast the USB direct is flatter in presentation with what feels initially like more crisply delineated note edges but is more of a simplified rendering with a little glare or shoutiness on top and which gets a bit congested in the busier passages.

Caveat is of course it’s my system and my ears.

I had previously put this down to - not any limitation of the USB cable per se - but to what I assumed was the comparative noisiness of a non-optimised ‘stock’ computer (Mac or not) incl USB board as source. As from memory using the Zen Stream’s galvanically isolated USB out was a little better.

Though it just occurred to me the 22 AWG silver USB cable probably requires some decent burn in.. I suspect I’ve only used it for a few hours if that after trying it briefly late last year.

What sort of burn-in would such a cable require do you think?

I’m keen to ensure I give it a fair go.

 

[Forgisound]

Nice write-up thanks. Excellent to hear you’re enjoying the R26 so much and thanks for sharing your experiences and preferred input. I too find it it really interesting reading of others’ different preferences, makes me challenge or check my own setup - which I’ve done and shared my observations below FWIW.


I have a pure silver handmade USB cable with some similarities to your Tubulus, if not quite as sophisticated or as expensive (I’ve also heard very good things about the Concentus IIS btw). The Gothic Audio Semperfi Outsider also puts the +5v power line on the exterior of the two layers of shielding of the signal and ground core cables.

https://gothicaudio.com/collections...-usb-cable-type-a-to-b?variant=32016533979194

I got it based on strong recommendations in another thread. It was certainly an immediate clear jump in performance over the silver plated high purity copper USB cable I used till then between the Zen Stream and the Gustard U18. https://www.aliexpress.com/item/32812730357.html

Your and @armstrj2 ’s comments prompted me to dust off the SemperFi cable and give it another whirl direct from my Mac Mini M1 to the R26. It didn’t take long to confirm my preference hadn’t changed and is similar to @Forgisound . I prefer the R26 direct ethernet connection in my setup - Roon/HQplayer NAA, LHY SW-8 and Netgear switches in series, OCK-1 clocking R26, basic cat 5/6 UTP cables, and recently a Puritan power conditioner & Quartz Acoustics grounding boxes (other gear per sig).

The R26 internal streamer in my system now projects a deep and wide soundstage with a beautiful organic feel especially apparent with vocals that are textured and sweet with no rough or sharp edges, along with lots of subtle acoustic clues of note decay and reverberation in a space. There‘s great spatial and dynamic separation and layering that is maintained even then things get really busy. In contrast the USB direct is flatter in presentation with what feels initially like more crisply delineated note edges but is more of a simplified rendering with a little glare or shoutiness on top and which gets a bit congested in the busier passages.

Caveat is of course it’s my system and my ears.

I had previously put this down to - not any limitation of the USB cable per se - but to what I assumed was the comparative noisiness of a non-optimised ‘stock’ computer (Mac or not) incl USB board as source. As from memory using the Zen Stream’s galvanically isolated USB out was a little better.

Though it just occurred to me the 22 AWG silver USB cable probably requires some decent burn in.. I suspect I’ve only used it for a few hours if that after trying it briefly late last year.

What sort of burn-in would such a cable require do you think?

I’m keen to ensure I give it a fair go.

The lower the signal voltage, the longer it takes to burn the cable. The USB cable has a very low voltage signal.

 

[Davidv100]

The lower the signal voltage, the longer it takes to burn the cable. The USB cable has a very low voltage signal.

… burn in of a USB cable…
Are we sure we are not going too far here in the alternative world ???

 

[OhHeyItsLou]

Nice write-up thanks. Excellent to hear you’re enjoying the R26 so much and thanks for sharing your experiences and preferred input. I too find it it really interesting reading of others’ different preferences, makes me challenge or check my own setup - which I’ve done and shared my observations below FWIW.


I have a pure silver handmade USB cable with some similarities to your Tubulus, if not quite as sophisticated or as expensive (I’ve also heard very good things about the Concentus IIS btw). The Gothic Audio Semperfi Outsider also puts the +5v power line on the exterior of the two layers of shielding of the signal and ground core cables.

https://gothicaudio.com/collections...-usb-cable-type-a-to-b?variant=32016533979194

I got it based on strong recommendations in another thread. It was certainly an immediate clear jump in performance over the silver plated high purity copper USB cable I used till then between the Zen Stream and the Gustard U18. https://www.aliexpress.com/item/32812730357.html

Your and @armstrj2 ’s comments prompted me to dust off the SemperFi cable and give it another whirl direct from my Mac Mini M1 to the R26. It didn’t take long to confirm my preference hadn’t changed and is similar to @Forgisound . I prefer the R26 direct ethernet connection in my setup - Roon/HQplayer NAA, LHY SW-8 and Netgear switches in series, OCK-1 clocking R26, basic cat 5/6 UTP cables, and recently a Puritan power conditioner & Quartz Acoustics grounding boxes (other gear per sig).

The R26 internal streamer in my system now projects a deep and wide soundstage with a beautiful organic feel especially apparent with vocals that are textured and sweet with no rough or sharp edges, along with lots of subtle acoustic clues of note decay and reverberation in a space. There‘s great spatial and dynamic separation and layering that is maintained even then things get really busy. In contrast the USB direct is flatter in presentation with what feels initially like more crisply delineated note edges but is more of a simplified rendering with a little glare or shoutiness on top and which gets a bit congested in the busier passages.

Caveat is of course it’s my system and my ears.

I had previously put this down to - not any limitation of the USB cable per se - but to what I assumed was the comparative noisiness of a non-optimised ‘stock’ computer (Mac or not) incl USB board as source. As from memory using the Zen Stream’s galvanically isolated USB out was a little better.

Though it just occurred to me the 22 AWG silver USB cable probably requires some decent burn in.. I suspect I’ve only used it for a few hours if that after trying it briefly late last year.

What sort of burn-in would such a cable require do you think?

I’m keen to ensure I give it a fair go.

I also have the Concentus I2S and can confirm, it’s excellent. If memory serves me correctly I believe burn-in recommendation is 100hrs up to 300hrs for optimum performance.

 

[Forgisound]

… burn in of a USB cable…
Are we sure we are not going too far here in the alternative world ???

The cable doesn't play as well as it can at first. The wire, and especially the insulation, need playing time to work optimally. Same with amplifier, DAC, speakers...

 

[Davidv100]

The cable doesn't play as well as it can at first. The wire, and especially the insulation, need playing time to work optimally. Same with amplifier, DAC, speakers...

But in a USB cable… what do you intend to burn in ???

The only thing that can matter in a USB cable is :
- no power pollution
- good connectivity for signal transfert so that packets of data are not refused and resent…

But after that, there is no distinction between sorts of “0” and “1”. It’s not like I’m analog where there might be differences in behavior between low and high frequencies…

There is no “this USB cable gives a better midrange” or whatever. The cable is good, globally or not, in its ability to transfer information, without distinction of the content of the information.

What do you want to burn in here ?
- Increase the speed of light ?
- Make the isolant more isolant over time ? Will the shielding shield more ?

When you buy a new MacBook, do you first let it burn in for 200 hours ?

And before that, is Excel or Word making mistakes ? Are there rounding errors ? Are the PowerPoint presentations more beautiful after burn-in of the Macbook ?

Some truths or beliefs from the analog world just do not apply to the digital world…

For example, in analog signal cables, there are reasons why cables with silver may sound more or less brilliant, and this has to do with the frequency of the signal.

There is no such things in a USB cable. There is only one frequency.

Burn in ?

Speakers yes.
Tube amps yes.
R2R Dacs yes (after all resistors are like small light bulbs).

But USB cables : no.
No burn in.

 

[Forgisound]

But in a USB cable… what do you intend to burn in ???

The only thing that can matter in a USB cable is :
- no power pollution
- good connectivity for signal transfert so that packets of data are not refused and resent…

But after that, there is no distinction between sorts of “0” and “1”. It’s not like I’m analog where there might be differences in behavior between low and high frequencies…

There is no “this USB cable gives a better midrange” or whatever. The cable is good, globally or not, in its ability to transfer information, without distinction of the content of the information.

What do you want to burn in here ?
- Increase the speed of light ?
- Make the isolant more isolant over time ?

When you buy a new MacBook, do you first let it burn in for 200 hours ?

And before that, is Excel or Word making mistakes ? Are there rounding errors ? Are the PowerPoint presentations more beautiful after burn-in of the Macbook ?

Some truths or beliefs from the analog world just do not apply to the digital world…

For example, in analog signal cables, there are reasons why cables with silver may sound more or less brilliant, and this has to do with the frequency of the signal.

There is no such things in a USB cable. There is only one frequency.

Burn in ?

Speakers yes.
Tube amps yes.
R2R Dacs yes (after all resistors are like small light bulbs).

But USB cables : no.
No burn in.

A lot of discussion has been held about it. I don't want to get into a technical discussion. But most audiophiles who have tried different USB cables, find that they don't sound the same. It is not discussed much anymore. The same is the case with I2S cables, LAN cables, etc., but there are fewer people with hearing experience who have tested them.

 

[Davidv100]

A lot of discussion has been held about it. I don't want to get into a technical discussion. But most audiophiles who have tried different USB cables, find that they don't sound the same. It is not discussed much anymore. The same is the case with I2S cables, LAN cables, etc., but there are fewer people with hearing experience who have tested them.

They are talking about the global quality of the cable (good transfert, good shielding, power isolation). Same for LAN cables, I2S cables…

Please let’s not confuse this with ideas like “Break In of the USB cable”.

Imagine how many people at work will tell their boss their coding work will improve after 200 hours of break-in of their USB cable…

Sorry, but just : no.

 

[Forgisound]

They are talking about the global quality of the cable (good transfert, good shielding, power isolation). Same for LAN cables, I2S cables…

Please let’s not confuse this with ideas like “Break In of the USB cable”.

Imagine how many people at work will tell their boss their coding work will improve after 200 hours of break-in of their USB cable…

Sorry, but just : no.

My Wireworld Platinum Starlight USB cable took 50 hours to start playing better than a regular computer USB cable. I believe he was slightly improving even as much, if not longer. And the solder needs a certain number of hours to stabilize. And then there are wires and insulation. You are absolutely wrong.

 

[camrector]

but all my other gear doesnt trigger the out if phase light

sorry if I missed it but does the light go off if you invert the phase in the R26 menu?

 

[Davidv100]

My Wireworld Platinum Starlight USB cable took 50 hours to start playing better than a regular computer USB cable. I believe he was slightly improving even as much, if not longer. And the solder needs a certain number of hours to stabilize. And then there are wires and insulation. You are absolutely wrong.

Ok…
Just, remember to burn-in your next MacBook or PC too… Lot’s of soldering in there. And for the first 50 hours, I recommend not to trust your Excel results… lots of rounding errors during burn-in. Underrated issue.

 

[Forgisound]

Ok…
Just, remember to burn-in your next MacBook or PC too… Lot’s of soldering in there. And for the first 50 hours, I recommend not to trust your Excel results… lots of rounding errors during burn-in. Underrated issue.

You'd better find an experienced audiophile nearby to give you a demonstration. This discussion makes no sense.

 

[Davidv100]

This discussion makes no sense.

Exactly my point.
Glad we agree.