[aceinc]

If you have a streamer, in my case I have WiiM Ultra, and you have a DAC, in my case I have a highly rated inexpensive S.M.S.L su-1, what can be done to resolve potential noise injection from commercial/consumer grade network infrastructure gear?

I would posit that connecting all digital devices to your streamer and then connect the streamer to the DAC via optical (TOS) should remove all (most? a lot? of) potential EMI/EFI and sloppy data transfer injected into the copper portion of the ethernet infrastructure.

My conjecture is based on the assumption that the streamer when internally building and buffering the input and then converting it to optical will logically (using software/firmware logic) tidy up all the garbage and present a nice clean digital stream to the DAC.

If you want to get ridiculous about it, make sure the DAC has the cleanest power it can get (battery?) and place it in a well designed & grounded faraday cage.

My ears may not be good enough, my system may not be revealing enough, or I am lucky, but I cannot hear the difference between plugging the USB cable from my computer directly into my DAC, or doing what I suggest above. So I will leave it up to other folks (like a guy I met yesterday who spent $7,000 on an ethernet switch and swears he can hear the difference) to give this a try and see if it obviates the need for expensive cables and other network infrastructure.

BTW, My home infrastructure includes cheap <$50 switches, CATx (5/6/7) cables of unknown origin, 20 year old (maybe older) in wall CATx cable a patch panel at least that old...

[newzooreview]

The comparison seems to be between two comparably poor methods of connecting the DAC: USB directly from a PC or via Toslink to a WiiM Ultra.

If you enjoy the system then it doesn't much matter, but this "simple/inexpensive trick" is not going to get the best sound from most systems.

[aceinc]

The comparison seems to be between two comparably poor methods of connecting the DAC: USB directly from a PC or via Toslink to a WiiM Ultra.

If you enjoy the system then it doesn't much matter, but this "simple/inexpensive trick" is not going to get the best sound from most systems.

Perhaps you misunderstood my concept. (Or I am misunderstanding your insight)

What I am suggesting is that the streamer takes all electrical digital inputs, ethernet, coax, HDMI, USB, etc. and acts as a traffic cop (aggregator), sending the reconstituted digital signal to a separate DAC over TOS. The purpose being to isolate all potential electrical noise in the streamer keeping it from the analog side of things where it could impact SQ.

Part of my reasoning is that a streamer which needs to deal with all manner of data input from WiFi to Ethernet to Bluetooth. Some of the issues these media introduce include delays, packet loss & retransmission, etc. To handle these issues a streamer should have a more robust digital processing capability including larger buffers and better error handling than most DACs. However if you use the DAC in the streamer, it could, unless extremely well designed and implemented, allow EMI/RFI noise coming from its various digital inputs pollute the analog signal to the amplifier. By having the streamer rebuild the digital signal and send it via an optical interface none of that RFI & EMI can get to the DAC.

[newzooreview]

I understand the theory.

Jitter in TOSLINK connections arises from timing inaccuracies in the digital audio signal: the source device’s unstable clock, introducing timing errors; the TOSLINK transmitter and receiver, where electrical-to-optical and optical-to-electrical conversions add jitter; and the optical cable itself, where the typically plastic fiber’s high attenuation and dispersion degrade signal integrity.

There are no solutions, only tradeoffs.

The sources of distortion that need to be minimized with Toslink are different from the sources of distortion that need to be minimized when using S/PIDF or Ethernet. One could propose an equally compelling theory for the superiority of S/PIDF or Ethernet.

In reality, any of them could sound better if the system is optimized to address the challenges of the connection type being used. Unfortunately, the manufacturers of streamers and DACs don't know or don't provide meaningful information about these issues.

What works in one system might not work as well in another.

[Tyson]

You can avoid the need for optical isolators if your streamer or DAC have galvanic isolation. 

[aceinc]

You can avoid the need for optical isolators if your streamer or DAC have galvanic isolation.

This is very true. What I am trying to implement is galvanic isolation with equipment you may already have, or with equipment which is budget level.

[WGH]

If it was as simple as using a $5 TOSLINK transmitter (I checked at Mouser) and the data transmitted would be cleaned up resulting in better sound then everyone would be doing it. My DAC doesn't even have an optical input. Optical output is usually limited to 24 bit/ 96 kHz resolution which is high enough for my friends that have ANK DACs but not for me. ANK DACs don't have an optical input either and the company is all about excellent sound.

The  S.M.S.L SU-1 DAC is powered by a USB-C cable which also carries data and requires a 5V 1A power supply. I get much better holographic sound along with tighter, deeper and clearer bass whenever I use a linear regulated 5v power supply. I use a couple of Acopian power supplies in my music server. The 5v Acopian 5EB200 can be bought used on eBay for $20 and has excellent specifications with the load 0.25%, line 0.05%, and ripple 1 mV RMS.

The Acopian Series A - High Performance (model numbers begin with the letter A) have regulation and ripple specifications that are even tighter with the load + - 0.005%, line + - 0.005% and ripple 0.25 mV RMS.


I didn't see a separate 5v input on the S.M.S.L SU-1 DAC so you would have to open it up and add a jack bypassing the dirty 5v USB line.

[Rusty Jefferson]

.... but I cannot hear the difference between plugging the USB cable from my computer directly into my DAC, or doing what I suggest above....

Do you hear a difference between using the internal dac in the Wiim and the external SMSL?  You could pass a A/B/X test?

You can avoid the need for optical isolators if your streamer or DAC have galvanic isolation.

That is an over simplification (imo). It's not that simple.

....What I am trying to implement is galvanic isolation with equipment you may already have, or with equipment which is budget level.

Because you're confident it will have an audible improvement on this system?

[aceinc]

After a bit more research, I think the concept is M/L sound, however TOSLINK will not support higher bit rates required for DSD128 & above.

However, if I thought I could hear the difference, to achieve galvanic isolation, and I were AR, I might consider the following;

• A moderately sized LiFePo battery with a charger for power. I would turn off the charger when listening to music, and keep the battery separated from the rest of the equipment.
• A streamer with a reasonable DAC, or a separate DAC, connected via as short a USB cable as possible (properly spec'ed of course, but not esoteric).
• Turn off the wireless & BT in the streamer.
• A pair of fiber optic to 1gbps ethernet adapters and appropriate length fiber cable to connect the streamer to the network.
• Connect the streamer/DAC & fiber optic transceiver (only the one attached to the streamer) to the battery (DC power)

This should remove virtually all sources of EMI & RFI for a price which is much less than;

https://houseofstereo.com/products/nordost-qnet-network-switch

First let say I am not convinced (but I am willing to be convinced, should empirical evidence be presented) that a reasonably well designed streamer and/or DAC need galvanic isolation, or any other extraordinary measures (beyond decent consumer grade switches & wires and a bit of care in placement of components) to achieve very good results.

Having said that, if you want to try something which is not terribly expensive and should theoretically remove EMI & RFI from the digital signal, the above may work. Or you just have too much time on your hands, give it a try & let me know the results.

[aceinc]

Do you hear a difference between using the internal dac in the Wiim and the external SMSL?  You could pass a A/B/X test?
That is an over simplification (imo). It's not that simple.
Because you're confident it will have an audible improvement on this system?

Rusty, see what I was typing as you were posting. The answer is no I am not sure I can pass an A/B/X test on any of it, but there are people willing to pay thousand$ for esoteric switches, etc. Some other folks who really can't afford thousands (at present) may lust after audio bling, and I thought I would provide a possible path to get the same results with less money spent.

[Rusty Jefferson]

What you just outlined is essentially what I would have suggested but seemed too expensive for the system you're working on. That would be appropriate for streaming via Ethernet over the network, but still wouldn't fix issues with usb, s/pdif, hdmi inputs.

If you don't need the SMSL, there's some money to sock away for improving your front end. If you made those upgrades and then tried an audio switch just before the streamer, you'd likely hear another level of improvement. But then you'd be at a level that would justify a better streamer.....and so it goes in this hobby.

[brj]

What you described is essentially what I have, but in my case it was done partly because it was actually cheaper than to have to source quality linear power supplies everywhere I had an SMPS or cheap wall-wart style LPS.  (It helps that all of my audio gear is in the encapsulated crawl space below my listening room, so I have more freedom to spread things out than most, and fewer aesthetic concerns to boot.)

In my case, I was always going to have a streamer (since I use HQPlayer, such that the "streamer" is really a small computer to act as an HQP NAA), and the USB cable was the baseline whether using the streamer or directly connecting to my server, which I did before going the NAA route.  So this part of the architecture was not impacted by any battery or isolation considerations.  Similarly, my network configuration already assumed a fiber optic network aggregation switch, as it's far nicer to run fiber through my walls than fat CAT6A cable.  So even that wasn't a cost upper to my audio configuration.  (The other reason I went fiber for the aggregation switch is that it allows me to isolate the network from data line surges, as it provides the connection between my cable modem and the network - so if a surge comes in on the cable line, only the the cable modem dies, as the fiber link from modem to aggregation switch protects that switch and everything behind it.  I implemented such protection-oriented isolation previously using a set of media converters, which I now have up for sale.  At $269 dollars, that fiber aggregation switch provides a lot of benefits...)

After a decade of using SLA AGM batteries with a CTEK 7002 charger, I recently switched to LiFePO4 and a Victron charger.  (My first SLA lasted 8 years, but the second died after 2 due to an accidental deep-cycle, so I switched to LiFePO4 for the significantly increased longevity.)  I should note that I have a PI Audio BatteryBUSS (no longer sold) to handle the actual DC power distribution.  But battery + charger + BatteryBUSS was still cheaper than sourcing ~4 quality power supplies.

The battery powers the digital streamer (SFP equipped Fitlet3), a TP-Link media converter ahead of my subwoofer crossover (even though the Ethernet on that device is for programming/control only, not data), the logic circuits of my pre-amp, an IR blaster, and the old Apogee Element that I use as a room-measurement mic pre-amp and Toslink bridge from my TV to my audio server.  (Toslink here was a matter of convenience, as it connects to my music server which is upstream of the fiber optic switch, but before I had the NAA, this did provide isolation per your intent.)

So for me, the only concession to isolation that wasn't otherwise cost driven was the decision to put a media converter in front of the subwoofer crossover.  But that media converter, fiber transceiver and Beldin Ethernet cable was still less than $100 total.

Of course, if your DAC doesn't need power on the USB cable (i.e. data lines only) and isolation was your only focus, you could go even further and just use a fiber optic USB cable from streamer to DAC.  (You'd have to explore this a bit though, as some need separate power inputs on one or both ends, depending on use and the equipment into which it's plugged on either end.)