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

[mikeypas]

Finally received my U18, connected to R26 via I2S. Sounds lovely, but still only a couples of hours into it.

I believe I got the R26 to play friendlier on my network LAN side, so would love to A/B U18 vs FMC on my system.

I previously purchased some FMCs and LC cabling but returned it all because the R26 wasn't working too well on LAN.

Now for the multiple FMC purchase questions:
1) The FMC I purchased had a LC to LC connection, single port. The TX side of the port was available to use, but the RX seemed to be soldered shut. So in a sense I was going TX - TX instead of TX - RX. I don't see any sets of FMC being sold that has one side open for TX and the other for RX? (see attached photo)
Would dual port help alleviate this, since both TX and RC are connected at same time?

1) For the FMC: Multimode or single mode? single port or dual port? LC or SC SFP module? (or other type?)
2) Cabling: single mode or multimode? simplex or duplex?
3) Now I have R26 connected directly to the router, I assume that the FMCs will go between router and computer.

I searched for the recommended finisar aoc modules that people are referring to, but at least in canada, was a little $$$. I just want to dip my toe in the FMC world to compare against U18 DDC.

Thanks

 

[kumar402]

Finally received my U18, connected to R26 via I2S. Sounds lovely, but still only a couples of hours into it.

I believe I got the R26 to play friendlier on my network LAN side, so would love to A/B U18 vs FMC on my system.

I previously purchased some FMCs and LC cabling but returned it all because the R26 wasn't working too well on LAN.

Now for the multiple FMC purchase questions:
1) The FMC I purchased had a LC to LC connection, single port. The TX side of the port was available to use, but the RX seemed to be soldered shut. So in a sense I was going TX - TX instead of TX - RX. I don't see any sets of FMC being sold that has one side open for TX and the other for RX? (see attached photo)
Would dual port help alleviate this, since both TX and RC are connected at same time?

1) For the FMC: Multimode or single mode? single port or dual port? LC or SC SFP module? (or other type?)
2) Cabling: single mode or multimode? simplex or duplex?
3) Now I have R26 connected directly to the router, I assume that the FMCs will go between router and computer.

I searched for the recommended finisar aoc modules that people are referring to, but at least in canada, was a little $$$. I just want to dip my toe in the FMC world to compare against U18 DDC.

Thanks

Single Mode/Multimode and dual port and single port are not related. Devices with dual port can work in single mode. If you have to buy FMC buy single mode and wavelength supported by it like 550nm or 1310 nm then check if the input take LC or SC and using above buy good fiber cable. Take LAN out from Router and put it in 1st FMC connect 02nd FMC via fiber cable if dual port then RX of one will go to TX and vice versa and take LAN out from it into your streamer
I would suggest to use amazon link provided by members in this thread to get the bundle if there is confusion.

 

[duffer5]

Single Mode/Multimode and dual port and single port are not related. Devices with dual port can work in single mode. If you have to buy FMC buy single mode and wavelength supported by it like 550nm or 1310 nm then check if the input take LC or SC and using above buy good fiber cable. Take LAN out from Router and put it in 1st FMC connect 02nd FMC via fiber cable and take LAN out f from it into your streamer
I would suggest to use amazon link provided by members in this thread to get the bundle if there is confusion.

What @kumar402 said. Nicely summarized.

 

[Deleeh]

Are you saying that the right one for 220V is 2A and not 3.15A? However, I will never spend $200 for the SR Purple fuse...

Hello,
not 2.0A/T but 2.5 A/T is used - at least this was the case with my Eu version.To be on the safe side, check what you have installed in your unit.

The rest I would clarify with Gustard themselves whether they can go higher.
As a rule, I always install what is installed.
(So disconnect everything and open the back and see what is installed and write down the value and order accordingly).
There was one exception with my tube amplifier.
It says 1.6 A/T, but it was a 1.25 A/T from the manufacturer.
This can happen when there is nothing left or parts were probably not available at short notice.

I can't say anything about high-priced fuses.I have never held one in my hands.

 

[mikeypas]

Single Mode/Multimode and dual port and single port are not related. Devices with dual port can work in single mode. If you have to buy FMC buy single mode and wavelength supported by it like 550nm or 1310 nm then check if the input take LC or SC and using above buy good fiber cable. Take LAN out from Router and put it in 1st FMC connect 02nd FMC via fiber cable if dual port then RX of one will go to TX and vice versa and take LAN out from it into your streamer
I would suggest to use amazon link provided by members in this thread to get the bundle if there is confusion.

The reason I asked is because this is what I previously ordered:
https://www.amazon.ca/dp/B09NKYQRMZ?ref=ppx_yo2ov_dt_b_product_details&th=1
https://www.amazon.ca/dp/B09ZTXSB51?psc=1&ref=ppx_yo2ov_dt_b_product_details

As you can see, the single port module only accepts fiber connection in TX. So how do I go from TX to RX on the other FMC?

 

[Jake2]

Yeah Finisar is the module to beat. Me just chilling for now until ER2 comes (if I am not swayed for some other stuf..).

Like the just released LHY SW-10 for instance?

https://www.beatechnik.com/product-page/lhy-sw-10

Credit to @Dandoudou for the heads up.

 

[BShaw]

Like the just released LHY SW-10 for instance?

https://www.beatechnik.com/product-page/lhy-sw-10

Credit to @Dandoudou for the heads up.

And I see the SW-10 has not just one TAMALE transformer like the SW-8, but two tamales. I love tamales.

 

[shogo33]

And I see the SW-10 has not just one TAMALE transformer like the SW-8, but two tamales. I love tamales.

You mean Talemas...i love tamales too

 

[BShaw]

You mean Talemas...i love tamales too

I guess my dry humor was a bit too dry…..but thanks for the correction shogo

 

[Dandoudou]

Yesterday, I discussed with a friend who tried a great number of SFP modules from Finisar and other good brands like Cisco.
And he has a nice collection of SFP modules. With some the sound is smoother, with others it's more resolving…

He recommended to me the Finisar 1318 for being the most satisfying SFP modules.

He recommended to me to use with any SFP module only this fiber cable, the Phoenix Contact Glass
Single-mode:

https://www.mouser.fr/ProductDetail/Phoenix-Contact/1115636?qs=OlC7AqGiEDnycJYzdFZJ3g==

 

[GP123]

FYI
If your attenuation is set to “on”, your DSD is being converted to PCM.

This is unfortunately incorrect. I got confirmation from Gustard that the attenuation function is done in analog domain. Their reply…

thanks for your reply.

yes attenuation in menu is a analog attenuator.

It works on the analog signal after d to a is done. So turning it on will not convert DSD to PCM. This option is independent and has nothing to do with the preceding NOS or DIRECT.

bset regards.

 

[Deleeh]

Hello,
It's fortunate that you bring it up.
Yes exactly "Attenuation" refers to the internal amplification output in the Dac to the amplifier, that's how I understood it, and not to the conversion, that's also what the manual says.
When it is set to OFF, the full power from the dac goes through to the amplifier.
Ergo, the volume pot reacts more sensitively to it when turned up.
Some people have complained about this, mainly on stereo systems.
(Consequently, the "signal is too hot/ringing present").

I didn't notice it at first, only towards the middle of the week.
I switched it to On and it was better, but the output is then very limited.
I could turn up my Feliks Euforia amplifier almost all the way, which is actually an impossibility.

There is an option somewhere to get around this by switching from Fixed to Variable on the Dac and finding your personal sweet spot.
I don't know exactly how to change it.
And yet I solved it in a different way via the software player.
Roon and Audirvana.
This way seems to me to be almost better to still get the full dynamic range.

I have written a small guide on how to adjust it.
However, please take care of your headphones and speakers.
Turn down the potentiometer on the amplifier first before you start, just to be on the safe side.
The R26 Attenuation function remains OFF.
Note that this is mainly for my headphone/set amp.
It may be that your system is more powerful than mine and you may need to adjust the Db range a little more.
However, I think -10Db seems to be a good starting point, and later you can always fine tune your system yourself.

The advantage of Roon is that it scales it down before it plays the track.
Audirvana also but see below.

As a note, it occurred to me earlier that you could theoretically practice the whole thing in reverse if Attenuatio is set to On.
But then you have to increase the db range in the software player if it is possible.
I have not tested/tried it.
It is easier to reduce the db range in my opinion.

Instruction:
This works regardless of which output you use, XLR or Rca and also reliably.
Roon Setup -10DB I2S

I2S uses a fixed volume output level and must/should be set when using the R26 with a DDC.

Right click on the detected I2S device and click Device Setup.
In the Volume Control grid, select DSP Volume Control and save.

Then click on the loudspeaker symbol at the bottom right and press the cogwheel at the top.
At the bottom right, press Volume Limits in the direction of the centre.

At the top of the bar, move the slider back to -10DB.
Under Comfort Limits, enter -10DB.
Under Protection Limits, enter -10 DB and save the setting.

Then go to the loudness symbol and turn it down by -10 so that it also shows -70db.

This setting is also transferred to Usb and Lan, but you should check whether the Usb connection is also fixed, and if so, change it to DSP.
It is important to note that if the R26 is running on different zones, then this procedure must be set again manually and separately for each zone as described above.
With the FMC speakers you could even go a little further down to -15 Db but that is subjective.

On Audirvana 3.5 it can also be adjusted, but it has a flaw.

Click on the detected device and click on this >.
Under Audio Volume, Maximum Audio Volume, move the slider back by about half, which is about -5db.
Volume balance:Title
Switch on the software volume control and press play. At the bottom right of the loudspeaker symbol, move the volume up.
However, you can play without play on the upper slider until you have set the volume to -5db at the bottom right of the loudspeaker symbol.
This is similar to what is necessary for Roon.

The next step is very important.
Scroll up and select At: D/A converter not recognised as Mqa: No Mqa
Automatically detect Mqa devices: Off

The last setting is very important if you are a Tidal user with Mqa in the playlist.
The reason is simple, if you have converted pcm and a Mqa song appears next, Audirvana will not automatically turn down the balance.

Because you tend to have turned up the volume on the amplifier, it is too much and very loud at that moment.
And dangerous for headphones/speakers and your own ears. That's frankly the crap about the old 3.5 software.
I assume that it was possibly solved better in the studio version, but I'm not sure about this.

You will notice that in the end you will get a much better feeling at the volume pot with full dynamic range and do without anything.
If you don't like it, you can undo it without any problems.

 

[camrector]

This is unfortunately incorrect. I got confirmation from Gustard that the attenuation function is done in analog domain. Their reply…

thanks for your reply.

yes attenuation in menu is a analog attenuator.

It works on the analog signal after d to a is done. So turning it on will not convert DSD to PCM. This option is independent and has nothing to do with the preceding NOS or DIRECT.

bset regards.

Dude you have no idea how far I went down this rabbit hole lol
DSD CAN NOT BE ATTENUATED BY THE R26
Dsd does not have the bit depth.

I had them drawn me a signal path diagram

 

[Jake2]

Dude you have no idea how far I went down this rabbit hole lol
DSD CAN NOT BE ATTENUATED BY THE R26
Dsd does not have the bit depth.

I had them drawn me a signal path diagram

Hi Cam, I think both statements can be true:
- use of the (digital) continously variable (1db steps) volume can't be done with DSD so requires conversion to PCM per the reason/process flow you provided
- use of the on/off (single ~-1030db step) 'attenuator' option in menu uses analogue attenuation per Gustard's reply to GP123 so no PCM processing or DSD/PCM conversion required.

 

[camrector]

Hi Cam, I think both statements can be true:
- use of the (digital) continously variable (1db steps) volume can't be done with DSD so requires conversion to PCM per the reason/process flow you provided
- use of the on/off (single ~-10db step) 'attenuator' option in menu uses analogue attenuation per Gustard's reply to GP123 so no PCM processing or DSD/PCM conversion required.

Ill ask again but there is nothing in the diagram indicating any attenuation in the signal path.
This is explicitly what I asked the guy and we went very in-depth on how the R26 processes Dsd. Never once did he say that it can be attenuated.

I think we are confusing gain control vs. attenuation control.