What is the added value of a streamer over a networked dedicated Computer

MHO.  I had a dedicated NUC I5 used as nothing but a roon endpoint.  Digital is digital right?  

A friend brought over an inexpensive streamer and it sounded better.

I bought the same $300 streamer and was very happy.

I then upgraded to a $4500 streamer.  There was more difference between the $300 streamer and the computer than the $4500 streamer and the $300 streamer.  

So there isn't a huge opportunity to improve here (like in a DAC for existence) but a dedicated streamer does a better job of managing the bits.

Jerry

the NUC is available.

I have direct experience in running dedicated Mini as both server/streamer and server only. Mine I7, PCIe ssd, Uptone MMK and JS2 LPS, running Roon as server only.

Based on your description greatest liability of present Mini is doing usb rendering within Mini, Mini very weak as renderer. You need to create second ethernet port via bridging of Thunderbolt. This https://audiophilestyle.com/forums/topic/30376-a-novel-way-to-massively-improve-the-sq-of-computer-audio-streaming/ will explain how to do this and also provide great info as to streaming in general! Believe me,  the bridge mod alone will totally transform sound quality!

So, what above means is Mini as currently implemented is far from optimal, the second ethernet port gives you ethernet out to a streamer which will do the critical function of usb rendering. Yes, you could do without the bridge and simply use a switch or router and then go from that to streamer, but this not nearly as good as bridging. This also comes from personal experience via use of audiophile switch.

Bottom line, using Mini for streaming not good, inferior renderer, relatively noisy device regardless of any mods one may undertake.

And then you have liabilities of Mac OS, from what I understand Audirvana Plus does a modicum of OS optimization on it's own, but much more can be done, need third party app wipe, go into Terminal to disable other processes such as System Integrity Protection (SIP), etc.

So, assuming you're willing and able to do all the above, you can have pretty nice server at this point, but a separate streamer still provides very large upgrade for sound quality. But then Audirvana really built for one computer setup, aka server/streamer combo, the server does the rendering. Roon optimized for two computer setup, the Mini or some other server and separate streamer. IMO, running Mini as one computer setup with Audirvana is far from optimal since requires Mini to do rendering.

So, you have the above considerations if keeping Mini. Another path would be to get rid of Mini altogether, if keeping Audirvana get server with optimized usb rendering, assuming you're continuing with usb. I'd seriously consider rendering capabilities of any server you consider for purchase, rendering is second most important component of streaming chain after dac. Point I'm making, many off the shelf servers don't have optimized rendering, which then requires adding a streamer or band aid usb filter 

 I should also add you could continue to use Audirvana with your Mini and streamer. My present setup running Roon utilizes Mini as server only, use Sonore OpticalRendu as streamer, extremely high quality streaming sound quality, beats my pretty nice analog setup. You could use OpticalRendu in your present setup, OpticalRendu has many choices for endpoint implementation which includes ability to use Audirvana. Also possible to implement other streamers with your present setup, just have to do the Mini mods I referred to above for optimal sound quality.

While Audirvana built for one computer setup, you'll still get benefit of superior rendering via separate streamer, problem is you're adding needless complexity. If wed to Audirvana I'd get very nice one computer setup vs keeping present Mini and adding streamer. Roon would be more advantaged with the added streamer. In either case, your Mini needs further mods for optimal sound.

There’s a lot of material on the forums that cover this, but l’m sharing a few posts that I wrote recently to help guide people on what is required in a great digital source, mainly around noise reduction and clocking/timing. Digital signals are very sensitive, and these two areas are the most significant challenges to get right to remove jitter/noise/ fatigue and enable the most natural, dynamic, and full-bodied delivery of digital music.

https://forum.audiogon.com/posts/2440486

https://forum.audiogon.com/posts/2441993

https://forum.audiogon.com/posts/2442047

https://forum.audiogon.com/posts/2445656

https://forum.audiogon.com/posts/2440669

@napoleoninrags16 

I had the same setup some years back. My mini was optimized with SSD and a better power cable, also the software was trimmed to eliminate all unnecessary processes. I enjoyed the hell out of it for a while. Then I got a Melco server/streamer. Everything got cleaner. The resolution was better, the soundstage and instrument separation were also better. The mini was no match. Still, one can live with the mini if it is implemented and setup right and upgrade when ready. If the Melco is a 10, the mini was a 7. 

@napoleoninrags16

You’re on the right track. As long as the digital data is getting to your DAC intact, there’s no reason to get a ’better’ streamer. It’s already doing the job it needs to do.

Jitter isn’t much of an issue. For example, most USB interfaces simply drop data packets if the data stream has too much jitter / error and this will manifest itself as an interruption in playback. If you’re using another digital interface like coax SPDIF or optical, large amounts of jitter will contribute distortion to the signal. If you want to hear what that actually sounds like, here’s a link - Let’s listen to some jitter simulations. Similarly, here’s what an underperforming digital interface sounds like (e.g. not enough jitter / error to cause a dropout).

Noise is another supposed bugaboo. Guess what? If you don’t hear any noise when your system is turned on and set to the volume you listen to, then it’s not a problem.

Digital signals are actually very robust. Think about it this way - if digital signals were fragile, how would the astronauts in the ISS be able to get a 600 Mb connection? How would people be able to stream audio or video from a service that stores the files in servers (which incidentally were probably also copied over a digital network) that are hundreds of miles away?

Yes. A high quality stand alone streamer will provide very large sonic improvements. 
 

I experimented for years with PCs and my Mac laptop… running on battery with most software shut down, with files in different places.

Then I got my first stand alone streamer: Aurlic Aries g2. That in a couple minutes put an end to my resistance to spending a lot of money on what amounts to a computer that looks like audio equipment. The question was dead. No more computers in my signal train. I then worked systematically from the bottom of the Aurender to the very top… and my system is now sonically the same as my great analog side.

Experience completely shut down any logical arguments in my mind. I have reasons I think for the difference… but the proof is in the sound quality. I now listen to streaming 95% of the time. 

What @ghdprentice said above. 

Also had a mac running audirvana, etc, etc. Identical results. Good luck!

@yage

I think Yage is on the right track. If the digital data is getting to your DAC and accurately represents the intended song data digital bits should be the same.   Assuming you have a properly functioning dedicated streamer and separate dedicated DAC of good quality - let’s say $500 and over for just the streamer and using wired connection and properly functioning cables, a digital 1 is a digital 1 and a digital 0 is a digital 0. DAC will have differences though. Properly functioning devices correct jitter and Ethernet has error correcting / FEC built in. I know people say they can hear the difference, and that is great and I don't think they are lying, but technically, I don’t know of any reason why some digital bits are better. I would like to see a comparison of the digital data after receipt and processing the the DAC USB to compare the bits between streamers. I always have an open mind.

That being said, computers and their OS tend to be difficult to get working properly, PC’s seem to be the worst. I have read the OS can resample the signal or the digital output of some motherboards can be really bad. I had a USB port on a motherboard once that could barely function for data I/O. You should try a good quality wire connected streamer and see if you can hear a difference. That is the real test, and be sure to let us know.

When designing and testing the Neko Audio D100 DAC, we happened across what we expect was an improperly constructed computer sound card. It was from a popular brand and a very common model of sound card. As a result, there was a significant amount of noise being transmitted out its coaxial S/PDIF cable, on the ground line.

The D100's input circuitry is designed to eliminate/mitigate that type of incoming noise, but otherwise the S/PDIF signal fidelity would have been negatively impacted. The impact of that could be either audible or inaudible, but regardless can affect the proper operation of the DAC or a downstream component it is connected to (i.e. noise traveling through the DAC's into the preamp). Safety testing checks for some of this.

That's one specific example of a possible relevant difference between digital transports.

Yeah, I went from primitive to high-zoot in one fell swoop, but the long and the short of it is that a dedicated, Ethernet-connected Streamer/DAC instantly gave me significantly better sound quality than what I got when I plugged my laptop's audio/speaker outlet into my integrated amp. . To be sure, the first streamer/DAC I purchased went belly-up within a week or so of its warranty expiring, but its replacement has yet to show a moment of ill-temper. I happily stream in hi-rez all the live long day. Even, ahem, CD quality streams can sound excellent.

If you are looking for the best sound, perhaps a better strategy is to set a price point and ask for streamer/server recommendations and then A/B the two approaches. That’s what many of us have done. If you don’t want to spend a good bit of money, then please avoid this approach because the A/B just drains the bank account because much of the time more money does buy better sound.

You can’t categorize one type of device as inherently superior to another in regards to digital sound “quality”. The devil is always in the details…..what two items specifically are being compared. It will sound really good either way these days when done similarly right. A lot of the differences claimed are here say based on personal preferences. In the past, problems with noise may have been more common on lesser quality computers but in general that is no longer a big deal. YMMV.

Huh? Computers are noisy. These stand alone audio devices have computers inside and great effort goes into mitigating noise/timing and isolating digital and analog. Also, much of the cost is due to the use of ultra quiet/stable power supplies.

Computers fail, there’re noisy and take up space. Streamers provide absolute simplicity.

Lose the MacMini for a cheap streamer. You won’t believe the difference. If you had wisely spent on music reproduction equipment all of the money you handed to Apple,

you would have a fine system.

Details? I don’t know anyone that tricked out a Mac enough to stop there. Most stop at an Amazon Echo before they even get there.

I have a Cambridge Evo 150 and have compared various sources for streaming including the on board streamer and class 2 USB audio input from Remote Desktop computer using the same source files. Both sound very similar, top notch. I’d really have to nitpick to say one is better than the other. Class 1 usb set on same input is much inferior. So you just have to have your technology being used to stream at a certain resolution lined up properly either way. Of course as always YMMV.

I have found the dac by far the most expensive , a dedicated line with 4 wire 2 grounds ,one dedicated isolated with seperate buzz bar and awg 10 was a huge step up in black back ground the little green computer with dedicatedlinear power supply ,withSS drives ,every bit as good as $5k streamers IHave compared with .

Not close. My Aurender N100H was vastly superior to my Mac Mini and Mac laptop as a source. Not remotely close…

Here is my advice, probably similar to the above in a nutshell:

1. Run the Roon Core (ROCK) on a Mini PC that is overbuilt compared to Roon’s ROCK specs. You can use a SMPS brick or if you want a LPS. Not sure it will make much difference. 
2. connect the above with a good Ethernet cable to an audiophile network switch. 
3. connect another good Ethernet cable to your separate streamer. Provide that streamer good power. 

Wow, seems to be some polarized responses.  I've been reading here and other forums to decide my next step and it seems fairly universal...  It's either very, very worth it to upgrade to a streamer or bits are bits.  I have to find a way to A/B this... I just got some decent speakers but only have a low end Denon AVR as an amp/DAC so not sure I'm ready  (but then forum posts often indicate AVR DAC's are fine).  Would love to try though.  I hope the OP posts his thoughts if he makes a change/purchase.   

Regards,

John

Music, when digitised, has two dimensions. It has amplitude, ie loudness, and it has frequency.

When being recorded it is sampled at a precise rate. If the data isn’t presented to the DAC at precisely the same timing of the original sampling when it was recorded it will sound poor. So, the data, which represents the amplitude of the music must be correct, and error correction techniques ensure this, but crucially the timing must be consistently spot-on too. That’s why different streamers etc sound different.

Noise is electrical mush which interferes with the timing of the data to the DAC, not audible hiss.

@john737 I have been at this digital game for 5 years now and no longer bother really with my legacy CDs or vinyl, I am 99% streaming.

But it has cost me $$$ to learn the following:

1. Buy a good streamer like Aurender or Innuos or Grimm etc

2. Buy a good DDC with internal or external LPS like a Singxer SU-6

3. Buy a good DAC with a proprietary USB input module alongside a host of other input types like BNC & AES, like a Denafrips or Holo Audio or Lampizator or Sonnet etc

4. Buy a good ethernet switch with a OCXO clock inside and which has an internal or external LPS, LHY, Melco and Nordost make good ones

5. Buy good digital cables like Shunyata or Furutech or AQ etc

The upshot is every link in the chain matters sonically and synergistically to one degree or another. Case in point, using fiber optic in the chain like I've done after getting a Lumin P1, which made a fascinating, VERY noticeable impact on clarity, separation and soundstage.

Finally, one last piece of advice - disregard anyone who chimes in on this thread with a "bits are bits" claim who has not spent serious time and money on optimizing their digital playback system... they don't know what they are talking about.

@john737 

Visit your local audio store and compare cheap bits are bits to more costly digital equipment.  Go listen for yourself.  Believe your ears and not what you read.

I think two important things to consider are what have you invested so far in your current platform (time, not money) and how do you plan to use the streamer. Personally, I prefer physical media. Nobody can take it away from me and having gone on an audio hiatus, the ability to come back and pick up where you left off is invaluable. So for me, I rip CDs and convert 78’s, 45’s, and LPs to DSD. I have about 10k pieces of physical media - been collecting since I was 12. About 40% of my collection is converted. I rate all of my songs and have it scaled down to about 45 days of 4-5 star songs. When I’m feeling lazy or preoccupied, I go digital and hit random. This is home, work and car. That’s about 270 days of listening for 4 hours a day without repeats. If I want quality, I go back to the originals. I have invested a lot of time in JRiver as my program of choice and it carries my organization when they can’t be embedded. If this was my only transport, I would feel differently. With a dedicated PC, a personal collection vast enough for me to forget a song exists between plays, and a good DAC, I don’t long for more. Since convenience is the attribute that separates my digital from my physical media, the idea of fiddling with 1 and 0s is not appealing to me.
The same could be said by some about analog. I’m comfortable with a meter, a control screwdriver and a magnifying headlamp. Others may be comfortable with a program. Me, when I have a digital issue, I end up somewhere on the dark web downloading a troubleshooting program. Now I believe a streamer (and based on what I read in threads like this - lots of other parts I just don’t understand) could improve my sound. However, with years already invested in my current process, it’s not worth it for me. This is largely because of how I use it. I often hear things like - great streamer, but the interface is just OK. In my opinion, the interface IS the streamer. If that’s clunky, where’s the benefit over physical media. And if that doesn’t pick up your current catalog and preserve the work you have done so far, don’t bother. 

Other than the fact that a dedicated streamer can be as good (and expensive) as you might desire, all of the factors are similar. You have one advantage of with a computer you can utilize it for other uses at the same time, but that is a trade-off because you must have the computer turned on to stream with even if you are NOT using it for other things and the computer probably draws more juice out of the wall just sitting there humming along. HTne with the computer you have access to just about everything that is available. there are a lot of things that a dedicated streamer can't access.

Relatively easy to understand optimal input on dacs, not so easy with the computers serving dac. First off, servers and streamers both computers, and it is the rendering service they provide that makes all the difference in obtaining maximum potential from dacs and streaming chains. Servers or one computer setups may or may not provide optimized rendering, many run rendering ports directly off motherboards, not good since these motherboards must run many processes allied to music players and OS, the more processes run the more noise produced, not good. The streamer has very little to do in comparison to server, motherboard runs very elemental OS, with focus on rendering, which means nice power supply and good clock. Servers very rarely provide this level of rendering, the few that do are easily $10k plus.

Get a nice streamer, server becomes much less important, not saying still not important, only less. In order of importance, dac, rendering, server, network.

There is one other way around two computer setup, streaming dac. Assuming quality rendering within dac one only needs to concern oneself with server.

I'd agree with those stating general service computer doesn't belong in quality streaming setup. There are means and paths to go diy through self builds and modifications of off the shelf GS computers, but one needs computer savvy. Add up time spent gaining knowledge, actually performing mods, expertise to carry out those mods, parts needed for these mods, Nope, vast majority better off getting off the shelf servers/streamers.

I started streaming using a higher-end Dell laptop, USB to the DAC.  I upgraded to a Roon Nucleus Plus server and the USB port is much quieter than the one on the Dell and the server maintains its self with no work on my end (other than responding "yes" when prompted to install software upgrades).  The sound quality is much better from the Roon server.

If you haven't done this already I would suggest that you compare a streamed album with one that you have ripped in FLAC. See if there's any difference in sound using your current setup.

In my case I have ripped my CD library (over 4k titles) into uncompressed FLAC but I still have all my CDs. I am streaming through an ASUS gaming laptop (I7 processesor) into the USB input of my PS Audio PerfectWave Mk II DAC. Note that the DAC has a "Digital Lens" feature that buffers and reclocks the data which should take care of any digital hash from the laptop. I also use Qobuz.

I have compared several CDs with the FLAC ripped version as well as the same version on Qobuz - all through the same DAC. The CDs go through my PSA PerfectWave Transport. I can't hear the difference between the three formats. They sound identical, or at least similar enough to not make a practical difference.

I wouldn't expect a FLAC version of one of my CDs to sound better than the CD itself. Using this criteria I can't see how an expensive dedicated streamer will help me. The other advantage of using a PC is that it can serve as the Roon core when I go with Roon at some point in the near future. BTW, the Qobuz version sounds the same as the other two formats which is to say that they all sound very good.

To put this another way, is anyone saying that a FLAC played through an expensive streamer actually sounds better than the corresponding CD played through the same DAC? If so, that is a demonstration I would really like to hear.

I read folks saying that an expensive streamer sounds way better than a cheaper option but I never see them using any sort of reference to help pin down the differences. I really think that you have to compare against a reference to get an accurate picture of how much difference there really is.

In the interest of clarity, since many call what I consider servers, streamers. What I'm speaking of is a DEDICATED streamer, many of us know this, but this is what is used in two computer setup. Only the DEDICATED streamer and/or really high end server/streamers do optimized rendering.

To be clear, the server provides music player library and music player processing ONLY, the DEDICATED streamer does only the rendering.

@napoleoninrags16 keeping it simple there is only one way a computer is equal to a high-quality streamer like an Aurender, and that is when the computer has been designed/built/optimized purely for sound quality. Taiko, Pink Faun, 432 EVO, Lampizator, etc., these companies all make music servers/streamers that are really optimized computers - they are very good but very expensive, on par with high quality streamers. So you can stick to a computer if you want, just don't kid yourself that any old computer will favorably compare sonically UNLESS your system is not resolving enough for it to matter.

I have essentially the same set up as the gentleman who started this discussion: 2012 Mac Mini: 2 tb Samsung SSD with 3000 ripped Cd's using AIFF or ALAC: Audirvania is controlled with iOs remote using iPad or iPhone. I use AQ Diamond USB connected through an AQ jitterbug: Power cable is a Synergistic Research Resolution Reference and the MM is plugged into the Discrete Symmetrical out of a Furman Ref IT-15: I use Audirvana to convert the CD Library to DSD128:  I,also, use a dedicated $1200 streamer connected with a AQ Eagle Eye silver coax cable and the same SR power cord. I use the streamer for Apple Music Lossless & Tidal: I have a parallel library on a macbook pro using a samsung ssd Amarra & Audirvana In my setup, the Mac Mini trumps the streamer every time. So I use it for music discovery and not for critical listening. Of course, this is my experience. Depending on equipment and room issues results can vary.

@Yage

The problem is that the digital data is robust, but you can't listen to it without converting it to analog.  That process is extremely time-sensitive and intrinsically imperfect.  Streamers like the Aurender mitigate timing errors in the signal transmission by buffering, but this only limits the signal jitter.

That said, if you don't hear a difference, then please share your experience comparing the 2 approaches in real life.

Computers fail, there’re noisy and take up space. Streamers provide absolute simplicity.

Streamers are computers

Streamers like the Aurender mitigate timing errors in the signal transmission by buffering, but this only limits the signal jitter.

rubbish. All streamers send packets of data. The DAC unpacks these packets. Any "timing" in the streamer is ignored by the DAC because the timing/jitter in the DAC is completely unrelated to the timing in the streamer and the switch. They are not correlated. Have fun spending big $$ on expensive clocks in streamers and switches, just be aware these timing signals from these expensive clocks do not affect the timing in the DAC in any way.

That said, if you don’t hear a difference, then please share your experience comparing the 2 approaches in real life.

Without wasting your time with the details. I’ve tried a LOT of cables, power supplies, switches, reference clocks , streamers, re-clockers, and so forth on the devices to feed data to my DACs. My experience is if you have a quality DAC.. all that stuff , like many other things in this hobby, is a complete waste of money. Like many other things in this hobby, many hear an improvement every time they spend more $$.

Paul McGowan (PS Audio) has a recent Youtube video which responds to this very question.

Having a dedicated streamer is a nice thing . But many already have computers and should at least try those first if that has appeal. It’s easy and can work very well. Just use a long usb wire so the computer is not too close to the amps for better chance of very good results. Also make sure to use drivers on the computer that are up to the task and stream good quality source material with a good quality streaming app. Then of course also use a good quality DAC. That can make a big difference.

I resisted a streamer for years. I finally purchased an iFi zen streamer and the jump in clarity was dramatic in my system. I have A/B’d the two setups repeatedly just to make sure. Your ears will answer your questions. Return the iFi on amazon if it doesn’t help your system. I kept mine.

Dear readers

I certainly do very much like to follow this discussion opened by napoleoninrags 16.

Which is, bdw a VERY interesting 'call sign' used in this forum'😉

100%, + mapman

In my system, there are totally 4 USB A-B connections (Oehlbach and ViaBlue) leading from 2 laptops (Win10) and 2 tablets (Android 7) into 3 different DAC's.  (SS Amp Cambridge Audio 751r, Marantz SACD player SE8005 and Hybrid Amp Vincent SV-500).

Streaming App's are JRiver with laptops and Audio Player Pro with tablets. The distance from the source to the DAC is 16 feet (2x), 8 feet and 3.5 feet.

My long term experience: Between these connections, I do not (cannot?) hear any difference regarding sound quality, which is really very good to my ears. I will have to check if I could hear a difference using my headphones (I am mostly listening over the speakers). BDW: I will later compare in detail the sound quality between USB A-B connection and HDMI connection from one source to the 751r. Just being curios...

Would it be worth to go for a dedicated streamer (price range US$ 200 to US$ 1'000)? I would need to find out and invest the money. Currently, I do believe that the investment of these bucks into the Quobuz Premier streaming plan is the way to go for me (Curiosity is killing the cat..). This is my personal opinion, based on my listening experience with my gear.

IMHO, instant-on is the only advantage, although streaming through my Amazon Echo starts just as fast. But if you have to boot up a laptop or tablet.... Otherwise, bits are bits.

 So, the data, which represents the amplitude of the music must be correct, and error correction techniques ensure this, but crucially the timing must be consistently spot-on too. That’s why different streamers etc sound different.

The timing in the streamer has absolutely nothing to do with the timing in the DAC. The clock in the DAC is completely independent from the clock in the Streamer and the clock in the Ethernet  switch. .... completely independent

@john737 - For what it's worth, I have Bluesound Node 2I streamer, modified Maverick Audio DAC, Pathos Classic One MkIII (Mullard Tubes), and Focal 836v speakers.  I have heard differences in power cords (on some components) and analog interconnects, but did not hear a difference when I switched digital coax cables.  I personal opinion is that it takes a very good system before the question of streamer vs. computer becomes a question worth answering.  I've heard clear differences among DACs and am actually rather happy that I am not compelled to go further upstream in my system.

@herman

The timing of the Streamer vs the DAC depends on the connection used. If you use the USB connection, then the DAC retimes the bitstream. If you use the S/PDIF or AES connection then the DAC uses the incoming timing. This is why it is important to try both.

My theory is that you should use the better component’s ability to time. I tried both the AES, S/PDIF, USB from my Aurender W20SE and Audio Research CD9SE DAC and found them all to be really… really similar, with the AES slightly better than the S/PDIF. But, I think it depends on your streamer and DAC.

The timing of the Streamer vs the DAC depends on the connection used. If you use the USB connection, then the DAC retimes the bitstream. If you use the S/PDIF or AES connection then the DAC uses the incoming timing. This is why it is important to try both.

agreed. When I'm talking "streamer" I was talking about the device that takes the digital data from the internet and then sends it on to the DAC via ethernet or wifi. Like a Roon Core or similar. If this is better termed a server then I have taken things off track, 

if others were considering it to be the endpoint that takes this stream and converts to a data stream for the DAC via AES or other input other than USB then I apologize for confusing things. With AES or SpDIF I do agree that the streamer clock is therefore very important. 

Thanks for all of these (very different) responses. 
When it comes to hi-fi, I do have much sympathy with the "subjectivist" approach as I think we still struggle to match what can be heard with objective measures or electrical theory. However I still regard digital and electrical understanding and measurement as important adjunctive tools, in part because they are necessary for designing kit, and also as a protection against "snake oil."

The responses above reflect the objectivist/subjectivist angles and I welcome hearing both. Ultimately over the last 40 years of owning and upgrading hi-fi I have always let my ears decide when purchasing gear as neither I nor most people are in a position to actually measure the digital data, inc timing, at various points in the signal pathway. As has been pointed out by one commenter, the "experience" of others who have invested in gear (whether digital or analogue) is likely psychologically biased toward justifying added expense, especially after the event. Yet no doubt many are quite right that their newly bought piece of kit has improved their system. 
 

It has become clear from the comments that some terms (like streamer/streaming) get used loosely and I am likely as guilty of this as others. It is also clear. That the implementation of computers varies widely, inc from my own usage - not all computers are the same, some are multitasking more than others, and there is a huge difference between outputting analogue through a headphone minijack and digital output, and indeed between the various options to output digital signal to a DAC.
 

So... as suggested  I need to provide a little more detail of my system and I also should explain further its current usage. I'll do that shortly in a subsequent comment.

Continuing from above, I already said in my OP that I don’t really listen to internet streaming (eg Spotify, or higher resolution internet sources) for serious listening. I appreciate the massive expansion in listening choice they offer but still prefer to have local "hard copy" and listen to that rather than be at the mercy of internet connection for uninterrupted/uncorrupted high quality audio. Perhaps my loose use of the word streamer in my question has given a different impression.

@Fuzztone re "If you had wisely spent on music reproduction equipment all of the money you handed to Apple, you would have a fine system. Details? I don’t know anyone that tricked out a Mac enough to stop there. Most stop at an Amazon Echo before they even get there."
I believe I do already have a fine system, thanks, and I gave no money directly to Apple since I bought the Mac Mini used. I did buy it as a way to get into SSD-based high resolution music files as well as convenient backup of my CD collection. That said, I remain interested in cost-effective upgrades to my system but am still unlikely to prioritise internet-streamed audio over locally stored music (or music via wifi) for serious listening in my dedicated listening room. I do send via Airplay to devices in other rooms when I’m in "party" mode but that’s not for serious listening. You (and others) asked for details. The system components are ageing but I have found that newer is often not necessarily better; furthermore earliest iterations of new technology direction have often been poor alternatives to traditional sources. My own view (open to alternative suggestions) is that the weak links in the digital chain are the 2 DACs. So my question about streamers is because I need to consider suitable interfaces/connections for digital sources/servers when upgrading the DAC, and also that I’m aware that some streamers come with an onboard DAC. I also recognise that internet-streamed audio will likely continue to improve in the future.

Analogue source: Audiomeca Romance turntable with Romeo uni-pivot arm, Van den Hul Condor Gold coil (LO) MC with suspension adjusted by vdH himself (begrudgingly!) for uni-pivot arm

Digital source 1:
Audiomeca Mephisto CD transport connected via BNC to Audiomeca Ambrosia DAC. This DAC was high end at the time of purchase but doesn’t handle high resolution audio. Nonetheless, over the years since I have auditioned other DACs and significant expense would have been required to improve on it significantly. One DAC I did demo at home which ran rings around it (but which I couldn’t afford) was a dCS Paganini.

Pre-amp: BAT VK30SE (Tube) with onboard phono stage
Power Amps: Audion Black Shadow 845 monoblocks (modified)

Loudspeakers: Coincident Super Eclipse III (92dB/14Ohm)

In addition to the above, as a weekend warrior musician, I was doing some home recording via MacBook Pro laptop and had already purchased an Edirol (Roland) multichannel USB interface for that purpose, capable of handling up to 24bit/192kHz data. This is essentially an ADC and DAC in one box with optical and MIDI in and out as well as USB. It’s connected to the preamp with audio note silver cables. When exploring high res digital audio files via the hifi, it made sense to me to begin with this device I already had. It also made sense to me at that time, if wanting to listen to such files using the hi-fi, to move from my laptop to a device not being used for other purposes and to keep those files along with my ripped (aiff) CDs on dedicated drives. Having done so, I have found the sound quality of the Audirvana/MacMini/Edirol combination remarkably good, given the price, such that I rarely listen to the original CDs. The situation is further complicated by the fact that the Edirol requires a driver and the drivers weren’t updated beyond the Mavericks OS, so the Mac Mini runs on that legacy OS and I can’t update the Mac Mini with later OS. However, since it’s dedicated to hifi listening and recording (not simultaneously), that’s not been a problem for me.

This is the context of my question on streamers, and I remain primarily concerned about the quality of handling of the music files on the drives (both the mac mini’s onboard SSD, and a couple of external drives with wired connections to the Mac Mini), as opposed to music which may be streamed from the internet. I am not expert in the technological details of rendering but was under the impression from what I read on the PS Audio website that, specifically with regard to timing issues, rendering by the computer was essentially (ahem) rendered irrelevant when playing music files from its SSD using a USB interface. Happy to be educated further by those with real expertise in this area.

Timing is usually a non-issue with USB since the advent of asynchronous mode. For a reference, see this document by XMOS, maker of USB audio interfaces used by manufacturers.  The key takeaway is on p.4:

Asynchronous mode enables external clock sources to be used as the master, or a low-jitter clock in the device.

Interfaces such as SPDIF (coax or optical) might exhibit higher jitter since clock recovery is done using the incoming digital signal though a clever scheme called biphase mark coding. However, considerable jitter needs to be introduced before audible effects can be heard.

Given that your DAC has multiple digital inputs and if you like the sound, I don't see a compelling reason why you couldn't use one of the other inputs for a streamer.

This is a great thread with great info. I started streaming on a PC. I have a used Node 2i coming this week to try it out. Fun to try new things.

The exclusive mode/driver/format changes on a PC are a pain so I want to try the node. In defense of the computer, it is nice to have one connected because it allows access to other content. I can watch or listen to concerts or songs on YouTube, netflix, or amazon or other music access web sites. Good way to sample and buy high res songs too.  We were watching a Zepplin concert and it was great. Sound was not high res, but still to listen and watch was fun.  Lots of great content on YouTube with the video - again, not perfect audio, but still good music.  

Just picked up an Aurender N200 and it is awesome.  So much better sounding than my PC to my DAC and also much better than the Vault 2i it is replacing 

I am loving this thing so far.   

Super quiet , good user interface,  super convenient,  sound quality is top notch.

Congratulations!
 

I remember the moment I heard my Aurender N100 for the first time… I couldn’t believe it. Finally, high end audio sound without a turntable. I quickly progressed to the N10 and finally Aurenders flagship, each more impressive than the last. Welcome to the club.