SMSL SU-2: a dumb, wasted opportunity

[Roland68]

Ah ok, but i told above i will use Relais Based Analogue one after DAC. for now i use Volumecontrol on CamillaDSP Software 64Bit till the Relais based is done (Work in Progress)

Here my Concept for my System:

View attachment 544372
I have 6 Boards from Twisted Pair for Volumecontrol but i want it in front of my Hypex Amps so i have designed new Boards in to the AMP enclosure with 833MHz Antenna for Syncronisation Volumelevel! Alternative with Cabel and RS422 connection but i guess 833MHz will work easier.

If you move one Encoder the Amp will Send the Volumelevel add to all Amp's Syncrone The DAC is on Top off the Amp so i need only to Route one ASE Cabel to the Box and Power 230V in the Same Cable

For now i move my Houshold in to an new Apartment, if iam done with that, i can work on my Setup again

My new Livingroom concept for 7.1 Setup with some Basstraps in the Corners + 2 SUBwoofer not on that Picture for now:

View attachment 544378

My CamillaDSP Concept with RME HDSPe AES Card you can find here:

https://www.diyaudio.com/community/...or-full-surround-digital-aktive-setup.440807/

With so many channels, I would recommend high-quality volume control ICs—such as those from MUSE or ROHM.
They offer far more flexibility, are much more space-efficient, and are likely more cost-effective, especially for balanced signals.

Using the NJU72315 ICs found in the SMSL D200, you could fit 10 balanced channels onto a 3 x 15 cm PCB, while still allowing enough spacing for optimal channel separation. However, the PCB and enclosure would likely need to be larger to accommodate the necessary connectors.

 

[Frunse]

No sorry, i used already PGA2320 Chips, so i like Relais and my Boards all fits in to the Chassis i have made an 3D Design already and the Relaisboards made already with KiCad need only to Order it.

You need more different Voltages for such Chips, relaise are full passive Signal pass with only 5V for Relais coil's on off.

I have an Arduino on the Main Board behind the Main Pannel with Display thats does the Controlling also controling the Hypex Amp Modules, Start and Standby, Temperture showing and so on. The Software needs only the 833Mhz Send and recive, than i am Done with it.

Look here for the Design:

https://www.audiosciencereview.com/...ole-lot-easier-and-cheaper.48233/post-2037162

 

[Herbert]

Hmm… aren‘t the (current?Not voltage?) outputs of the (ESS) DACs balanced anyway? So that you need an extra Opamp + circuitry to go single ended?

 

[Frunse]

Hmm… aren‘t the (current?Not voltage?) outputs of the (ESS) DACs balanced anyway? So that you need an extra Opamp + circuitry to go single ended?

The SU2 has both XLR and single ended, i need XLR for my Amps and i guess "yes" for single Ended there is one more Opamp needed in signal chain.

Here the PCB:

 

[Herbert]

So Balanced should be theoretically cheaper. And USB is lacking So where did the price difference of about 40$ between the SU-1 and SU-2 go? Power Supply? At least there are no Step-Up converters needed with the SU-2.

 

[Roland68]

So Balanced should be theoretically cheaper. And USB is lacking So where did the price difference of about 40$ between the SU-1 and SU-2 go? Power Supply? At least there are no Step-Up converters needed with the SU-2.

A larger housing, larger packaging, a built-in and proven switching power supply, an additional AES input, 4 x OPA1612A op-amps, more sophisticated circuitry for clocking and jitter suppression, and a more elaborate power supply design—these factors drive up the cost.
On top of that, price differences vary significantly depending on the country and retailer. At Shenzhenaudio, the price difference compared to the SU1 is only $17, whereas on Amazon DE, I paid about €25 more.
Another advantage is the improved measurement results, even if these are in the inaudible range. Furthermore, the DC/DC converter (generating +/- 12 volts) in the SU1 has frequently caused failures.

I clearly view the absence of a USB interface as an advantage. For around €35–40, you can get a high-quality DDC featuring the XMOS316 chip for USB connectivity, effectively creating a fully galvanically isolated DAC setup. This makes it not only one of the most affordable full-fledged balanced DACs (with an integrated power supply) on the market but also by far the most affordable solution for a galvanically isolated DAC.

 

[john61ct]

I clearly view the absence of a USB interface as an advantage. For around €35–40, you can get a high-quality DDC featuring the XMOS316 chip for USB connectivity, effectively creating a fully galvanically isolated DAC setup.

For only a little more, front end it with Eitr 2

3x concurrent S/PDIF outputs + AES/EBU via XLR, so 2x available for routing to other devices for bass management, ABX testing...

Forkbeard +$50 gets you preamp functions, phone becomes your auto-Loudness contoured volume control, also get remote source switching, some PEQ, balance etc

 

[Roland68]

For only a little more, front end it with Eitr 2

3x concurrent S/PDIF outputs + AES/EBU via XLR, so 2x available for routing to other devices for bass management, ABX testing...

Forkbeard +$50 gets you preamp functions, phone becomes your auto-Loudness contoured volume control, also get remote source switching, some PEQ, balance etc

In Europe, the device costs €159–219—not exactly a bargain. Factoring in the price of the SU-2, I’d just get an SMSL D200 instead.
I also don't think the measurements are as good as those of the PO100 2024.

I’m also not a fan of Schiit’s digital devices at all, whether DACs or DDCs. The measurements I’ve seen so far weren't that impressive, and the DACs I’ve listened to didn't win me over.
I found the USB interfaces on the recent Schiit DACs tested on ASR particularly unconvincing.

The Forkbeard module appears to be nothing more than one of those all-in-one Bluetooth modules used in many budget headphones and soundbars that offer this exact functionality. I’d be curious to see some independent measurements of it, though.

 

[john61ct]

In Europe, the device costs €159–219—not exactly a bargain.

Fair enough, that's a pity.

My understanding is, since the TOSlink output is limited resolution (to 192kHz?) there was no point implementing their usual USB-C Unison 384 interface (DXD, 32 bits/384 kHz)

so the FB functionality just uses the free "leftover" DSP processing capacity in the custom proprietary chip used for that main function.

One thing you can say about Schiit, they don't just use stock OTS functionality, if they do use non-bespoke chips, they certainly code their own algo's.

> SMSL D200

Then you miss out on the galvanic isolation you pointed out turns no-USB into a "hidden advantage"

> I’d be curious to see some independent measurements of it, though.

Me too, also the Vestri

 

[john61ct]

I'd love to find a cheaper DDC with USB --> AES/EBU for long distances BTW

But in this case I want the Eitr 2 anyway as user volume, just for the Loudness Contour

Apparently follows Dr Toole's reco, not just ISO 226:2003 compliance

This DAC just lets me use Eitr 2 's AES/EBU output, both S/PDIF left open for other mirror distribution / routing paths.

 

[Roland68]

I'd love to find a cheaper DDC with USB --> AES/EBU for long distances BTW

But in this case I want the Eitr 2 anyway as user volume, just for the Loudness Contour

Apparently follows Dr Toole's reco, not just ISO 226:2003 compliance

This DAC just lets me use Eitr 2 's AES/EBU output, both S/PDIF left open for other mirror distribution / routing paths.

The good interfaces with a USB input and AES output are either expensive or rubbish.

However, you can find I2S-to-AES and I2S-to-SPDIF boards on AliExpress and eBay starting at €25, along with compatible XMOS XU316 interfaces from €35.
I’ve used this combination quite a few times, even in professional settings. It’s affordable and performs well.

 

[Frunse]

For my 7.1 Setup i need 8 Stereo Dacs so SU-2 is the Cheepest option for AES in to Stereo XLR Out! With descend Measurings!
The only thing i miss may be is an switchable outputfilter.
Thats around 900€ for 8 SU-2 and i get 16 Channel Out from RME HDSPe AES Card with CamillaDSP.

Next nice DAC would be Shiit Mimir, may be, but thats already 300€ for one! 8x 300=2400€ for 16 Analogue Channels Out .......

If the Benefit worth so much more money ???? for the whole Setup????

 

[john61ct]

That cost-benefit judgment is 100% subjective, no one can balance that but you.

SU-2 measurements are great, what features do you think Mimir would help?

What do you mean by "switchable outputfilter" give examples?

I assume the host of the HDSPe interface card will be handling all the DSPing centrally?

Is your decision for power amp(s) and speakers already set?

Maybe active speakers, and/or accepting direct digital input, skip the added DAC?

 

[Frunse]

That cost-benefit judgment is 100% subjective, no one can balance that but you.

SU-2 measurements are great, what features do you think Mimir would help?

What do you mean by "switchable outputfilter" give examples?

I assume the host of the HDSPe interface card will be handling all the DSPing centrally?

Is your decision for power amp(s) and speakers already set?

Maybe active speakers, and/or accepting direct digital input, skip the added DAC?

Outputfilter:

https://addictedtoaudio.com.au/blogs/how-to/how-to-pick-the-best-filter-setting-for-your-dac

SU-2 looks this way:



I would like it this way!!!


or this way:



I don't like that ringing at all and with 96kHz samplingrate you could use such an slow rolloff without any Problem loosing some dB in Frequency Domain from 20000 to 48000Hz

This sharp Filter are only needed for 44,1kHz or may be 48kHz

Mimir has a lot off different Filteroptions thats the benefit on that Shiit DAC, they have his own Filter section added after DAC Ship. Not only that one used in Sabre DACship.

May be i buy one for testing and made than an descission if it makes sense or not after listening test, may be only for main Speaker and for surround i keep the SU-2.

And yes i have my own designed Speaker Setup (Harwood AM25, Scanspeak 18W/4434G00) and use HYPEX Amps 7x NC122mp and 2x NC250mp

And yes CamillaDSP on Linux with HDSPe AES Card is my Master for all Dacs connected with AES.

Like i posted anywhere already this is my Concept

 

[john61ct]

Thanks for answering so thoroughly and clearly, my opinions may not be useful for you but this may help you get better advice from others.

Haven't you created your own thread for discussion of your specific system yet?

It's free, and will allow you to avoid excessively diverting topic-specific threads like this, keep them more clean and focused (pot...black)

You can always use crosslinks to refer to relevant posts back in the other threads.

...

Schiit Mimir has not iirc been measured yet by the likes of Amir, and many expert members here will advise to avoid Schiit gear until it has been so vetted (I am not in that camp, and am 97.5% sure personally that Mimir is fine gear, just pricey as you say)

I would not rely so much on graphs, especially if future measurements show clear transparency, just trust that.

Of course you can test Mimir vs SU-2 and those filter choices with your ears, just try to get help making it a blind test, level matched - otherwise your brain will trick you into hearing differences not based on objective factors.

I agree on using Mimir for only critical output channels, especially on the more sensitive upper frequencies, SU-2 on less critical bass ranges?

I've already told you there is no advantage going over 48Hz, but perhaps you simply reject that as is your right.

I also question your choice of AES output from your DSP interface, I would choose one that directly outputs analog since that is what your chosen amps require as input.

AES/EBU output only helps if your cable lengths and/or noisy environment are causing audible transmission problems, and of course adds a lot of unnecessary cost otherwise.

 

[Roland68]

Thanks for answering so thoroughly and clearly, my opinions may not be useful for you but this may help you get better advice from others.

Haven't you created your own thread for discussion of your specific system yet?

It's free, and will allow you to avoid excessively diverting topic-specific threads like this, keep them more clean and focused (pot...black)

You can always use crosslinks to refer to relevant posts back in the other threads.

...

Schiit Mimir has not iirc been measured yet by the likes of Amir, and many expert members here will advise to avoid Schiit gear until it has been so vetted (I am not in that camp, and am 97.5% sure personally that Mimir is fine gear, just pricey as you say)

I would not rely so much on graphs, especially if future measurements show clear transparency, just trust that.

Of course you can test Mimir vs SU-2 and those filter choices with your ears, just try to get help making it a blind test, level matched - otherwise your brain will trick you into hearing differences not based on objective factors.

I agree on using Mimir for only critical output channels, especially on the more sensitive upper frequencies, SU-2 on less critical bass ranges?

I've already told you there is no advantage going over 48Hz, but perhaps you simply reject that as is your right.

I also question your choice of AES output from your DSP interface, I would choose one that directly outputs analog since that is what your chosen amps require as input.

AES/EBU output only helps if your cable lengths and/or noisy environment are causing audible transmission problems, and of course adds a lot of unnecessary cost otherwise.

Aside from the fact that cable runs to the DAC are inherently longer when there are so many speakers in a room, you are overlooking the most important point regarding the use of the RME HDSPe AES card:
namely, the synchronization of the master clock via AES for all connected DACs.
There are very few solutions for synchronizing two or more budget-friendly DACs within a single system, and this is one of the most affordable options. Beyond that, the cost becomes very high.

 

[john61ct]

Yes, with pro level equipment **on both ends** AES has a clocking precision advantage over S/PDIF

but with a cheap consumer DAC receiving iiuc that may not be true?

But analog from DSP interface to power amp should be fine anyway, just use true balanced for over long distances or in an EMI noisy context

 

[Frunse]

Aside from the fact that cable runs to the DAC are inherently longer when there are so many speakers in a room, you are overlooking the most important point regarding the use of the RME HDSPe AES card:
namely, the synchronization of the master clock via AES for all connected DACs.
There are very few solutions for synchronizing two or more budget-friendly DACs within a single system, and this is one of the most affordable options. Beyond that, the cost becomes very high.

All is syncronised thrue AES all DAC's get the same Clock sorce from RME Card, no drift to measure !!!

Also RME itself say it shuld run this way!!!

No Masterclock or anything like this needed!!!

I measured 30 minutes 3 DAC'S with 1khz signal, no drift at all, between them!

And my Thread is here:

https://www.diyaudio.com/community/...or-full-surround-digital-aktive-setup.440807/

And i told above, one of the best pro feature to use 96kHz!!! The Outputfilter don't need to be steap as possible so you can use Slow rolloff and didn't get ringing on Analogue Outs! Also Phase get less rotation at 20kHz range with slow Rolloff Filters. But for me it is my Target, you can do what ever you wan't and stay with 48kHz makes for you all cheeper!

But most time Cheep means lot's off compromise.

And i use 96kHz now for an Decade or longer with DSP's so why i need to go backwards in to the future

AES is made for up to 100M Range so why i need to use 2x XLR Analogue to the Speaker AMP when i can rout one AES with an Power Cord in one Cable to an Speaker (DAC and AMP neare Speaker) with this cabel??? And use short (0,5m) XLR Analoge Kabel from DAC to AMP.

https://www.thomann.de/de/stairville_ak_highflex_power_combi_cable.htm

I bought already 20Meter for first Tests

The Powercord will switched on from Central spot after switching the DSP on (16A Relais, industrial Garde, time controled, Hypex AMPS start up slowly so no bad Relaiscontactburnout could happen)

 

[john61ct]

Bit dicey cross-referencing between competing websites, but OK

 

[Frunse]

Bit dicey cross-referencing between competing websites, but OK

you got what you ask for