SMSL SU-2: a dumb, wasted opportunity

[rcstevensonaz]

So, for most precise time domain control overall, rather than relying on self-clocking interconnects my plan is to simply ensure that ALL the DA/AD converters have BNC WC capabilities both in & out.

With apology, I read your summary but I am still quite unclear what your actual audio chain is — and lots of statements that seem out of sync with prevailing wisdom of the ASR forum. But realistically, that entire conversation belongs in a separate thread, except for the specific part where you will be using multiple SMSL SU-2 DACs in parallel.

But I also do not understand why you are in this thread. The SMSL SU-2 is a device that does DA conversion but it has no support for Word Clock (WC) on either the input or the output.

 

[john61ct]

except for the specific part where you will be using multiple SMSL SU-2 DACs in parallel.

Sorry if that was not made clear enough but I was discussing @Frunse plan to do that.

Not so much discouraging that but pointing out his lack of concern for clock drift may turn out to be an issue.

I personally prefer to use pro-level interfacii / format converters

and ideally all with BNC word clock in & out but def the DA-AD, for DDC only if that does not blow out the per-port value proposition, currently $15-30 or so for most options I'm considering.

My overall system design is detailed here

Principles: Time of Arrival Delays, vs Phase tuning ?

Not relevant to the DSP stuff so much, other than PEQ & Loudness Contour testing, mostly up front analog source switching and defeatable "Processor aka Tape Loops"...

www.audiosciencereview.com

as much as possible anyway but as I stated the specific gear for "Modularised DSP ™ " clusters between the signals' initial ADC at 8ch and exit back to DACs at 22+ channels is very much going to depend on test results as I go.

Some examples

As good value for PC I/O as Echo Audiofire 12 ?

Total interface noob here, please ELI5 I don't need to record or mix music in the creative sense, just looking to get multi-channel analog in and out of HTPC type hardware. Primary use case is DIY convolving, loudness contour, bass management, room correction PEQ. The Echo Audiofire 12 unit...

www.audiosciencereview.com

ADAT interface hosts, high SQ but cheaper than RME Digiface USB?

I am looking for an interface "hub" based on multiple ADAT, clean and transparent. I'm not recording / mixing, just for recreational home DSP - crossovers timing delays / phase alignment tuning Happy to buy secondhand to save money, vintage discontinued no problem. 24-bit, 44.1 / 48kHz is...

www.audiosciencereview.com

Possible solution for DTS/Dolby/Atmos+eARC+HDCP to AES/EBU - via Dante? (for Okto DAC8PRO etc)

Other people have links in their signature, but I can't insert a link in mine, nor could I copy and paste the code from this post into my sig. Amrim turned that off. Some people are grandfathered.

www.audiosciencereview.com

...

 

[john61ct]

The SMSL SU-2 is a device that does DA conversion but it has no support for Word Clock (WC) on either the input or the output.

There are many use cases where that is not required, and no better value afaict for ones where AES3 input is desired

 

[rcstevensonaz]

There are many use cases where that is not required, and no better value afaict for ones where AES3 input is desired

Agreed. I can't find anything else that is a simple digital (AES, S/PDIF) to Balanced DAC... with nothing more. (And the D10B ticks that box for USB to Balanced.)

And in a case where the 8 individual SMSL SU-2 DACs are all receiving their respective digital input from a single upstream device, then they would all be perfectly clock synchronized because they all share the same upstream master clock. So there would be no need for external clock source since they are receiving a synchronized clock over the AES or S/PID.

 

[john61ct]

D10B ticks that box for USB to Balanced

A big bummer, learned no longer available.

> there would be no need for external clock source since they are receiving a synchronized clock over the AES or S/PID

Yes exactly that may be one of those use cases.

But when a "playing session" extends past a few hours, many sources I respect insist that BNC WC sync is "even better".

The issue is 1000x more critical with tweeter-level crossover frequencies within a single enclosure. ToA delays vs phase linearity tuning, or

bass frequencies, and Left stack vs Right, or Front group vs Back, not so much.

 

[Roland68]

A big bummer, learned no longer available.

> there would be no need for external clock source since they are receiving a synchronized clock over the AES or S/PID

Yes exactly that may be one of those use cases.

But when a "playing session" extends past a few hours, many sources I respect insist that BNC WC sync is "even better".

The issue is 1000x more critical with tweeter-level crossover frequencies within a single enclosure. ToA delays vs phase linearity tuning, or

bass frequencies, and Left stack vs Right, or Front group vs Back, not so much.

You're making a very simple error in reasoning there.
For you, the "playing session" lasts for hours, but for the devices, it only lasts until the next track or the next interruption. Then everything starts all over again.

 

[john61ct]

Aha good to know! But a TV or FM radio stream would still be the same continuous signal even spanning acoustic "silences" ?

 

[Frunse]

Agreed. I can't find anything else that is a simple digital (AES, S/PDIF) to Balanced DAC... with nothing more. (And the D10B ticks that box for USB to Balanced.)

And in a case where the 8 individual SMSL SU-2 DACs are all receiving their respective digital input from a single upstream device, then they would all be perfectly clock synchronized because they all share the same upstream master clock. So there would be no need for external clock source since they are receiving a synchronized clock over the AES or S/PID.

I wrote already that my Setup didn't had Phasedrifts between the DACS and already RME told me that there isn't any Problem if all DAC's works from one Source like an RME HDSPe AES Card all DAC'S geting the same Synced Clock over AES Connection, no external clock wil make enything better only worse at this Point!!!

 

[PGAMiami]

It’s too bad that just a tiny bit more thought wasn’t put into the SU2 regarding the goofy LEDs, mislabeled faceplate, turn on pop, unnecessary fade in … The performance is excellent, but it seems a bit half baked. AES3 is a pro format and I would think there would be some demand in the pro and prosumer market for these.

 

[rcstevensonaz]

... one Source like an RME HDSPe AES Card all DAC'S geting the same Synced Clock

I knew you mentioned an upstream source, but I'd forgotten what it was.

And yep, that single master clock means all connected downstream devices always remains synchronized to that clock source, doing what the technology was designed to do. And RME's internal clock technology is some of the best to start with.

 

[L-Train]

I took some time to measure all of the DACs I have available. All were measured with a 1 kHz tone at 48 kHz since the issue is most apparent at that sample rate with the SU-2:

Lynx E44 S/PDIF to Khadas Tone Board (aka Tone 1) (ES9038Q2M)
View attachment 552483

Douk Audio U2 Pro S/PDIF to Lynx E44 (CS4398)
- The Lynx E44 was configured to use the incoming S/PDIF signal as the clock source, and route the digital audio directly to its analog output DAC via hardware/FPGA routing
View attachment 552484

Fosi Audio DS3 USB playback (ES9039Q2M)
- Note that the DS3 inverts its unbalanced output
View attachment 552486

None of these DACs fade in or ramp from digital zero.

For posterity I'd like to add a result from my newly acquired DAC:

Lynx E44 AES to Topping D70 Pro Sabre (RCA out, firmware 1.11) (ES9039SPRO)

The D70 Pro Sabre doesn't fade-in from digital zero. According to the datasheet the ES9039SPRO has automute enabled by default, so it looks like Topping has explicitly disabled it in firmware.

The noisier silent section at the beginning is probably due to a slight ground loop since this is from the RCA output. All of my previous oscilloscope shots were isolated in one way or another (USB isolator or S/PDIF transformer).

 

[Bleib]

Don't worry, SMSL will come up SU-3 in three weeks to fix it.

Well. Soon

 

[Roland68]

Well. Soon
View attachment 560117

The device will have nothing to do with the SU-2.
It is a very small unit with the same chassis as the SU-1.
So, no built-in power supply and presumably no balanced connections either.

 

[devilhyt]

The SU-3 does have balanced connections. I think I’ll get one to play around with.

 

[rcstevensonaz]

The SU-3 ...

Perhaps we need a new thread for this device? Perhaps simply: "SMSL SU-3: a dumb wasted opportunity?"

 

[bachatero]

The SU-3 does have balanced connections. I think I’ll get one to play around with.
View attachment 560169

If it's below the price of a Fosi DS2 ($51-60) and TRRRS to XLR adapter ($15) then the SU-3 will be the new USB to XLR king!

 

[john61ct]

Had not come across Fosi Audio DS2 before.

Seems like a "great value" way to get balanced XLR line output from USB, e.g. Wiim Ultra.

Someone please correct me if I'm wrong, or suggest something more appropriate in the price range.

Also (anyone again) please link to such a good value adapter, Pentaconn to dual XLR is what that means correct?

 

[rcstevensonaz]

Seems like a "great value" way to get balanced XLR line output from USB, e.g. Wiim Ultra.

Someone please correct me if I'm wrong, or suggest something more appropriate in the price range.

Doesn’t WiiM Ultra have S/PDIF output? Why using the USB out?

For USB, TOPPING D10B was great option; but discontinued. So SU-3 may be the option to replace it.

 

[Frunse]

The SU-3 does have balanced connections. I think I’ll get one to play around with.
View attachment 560169

No AES in so no reworked SU-2 it's an new cheep DAC, thta's it. Probably reworked SU-1 i would say.

 

[Bleib]

Perhaps we need a new thread for this device? Perhaps simply: "SMSL SU-3: a dumb wasted opportunity?"

Well, it will be quite close to the price of Topping DX1 II which has a remote and a headphone amp so...