Weakest digital link: DAC - Streamer - Server?

Jitter being below audible thresholds?  I guess timing then just doesn’t matter. 

Today, for most digital USB in audio, i.e. USB and Ethernet, no, timing does not matter, not even a little. For SPDIF, most modern DAC chips and SPDIF receivers will remove every last bit of normal jitter. The rare time, very rare, make your SPDIF cable longer. Jitter stopped being an issue a long time ago in most setups.  I am sure there are some low volume DAC's that don't have the necessary circuitry to eliminate jitter.

Insulting someone's hearing is not going to make your point when you are unable to prove that your's is any better.

A lot of people use amplifiers, tube, many low feedback designs, etc. to alter the tone of their system. Those will definitely sound different from amplifiers designed to be a straight wire with gain. Some speaker cables may be tone controls. I guess an interconnect could be too. Some MIT seemed to be.

Too bad no amplifier is a straight wire with gain.

No, the speaker tends to interfere with that, but many come very close. I encourage you to take some amplifiers that identified as such and see if you can tell them apart without looking.

@invalid 

If that is the case, then you likely have a speaker/room issue.

How can any review of a piece of audio equipment not comment on the "sound" of the component at all?

Because some components, when designed that way, really don’t have a sound compared to their similarly designed peers. That people won’t accept that does not make it untrue. For components that do have a sound, the sound is dependent potentially on what comes before it, what comes after it, the speakers, the room, the person, their mood, to the point that listening impressions, for anything but speakers become nothing but a good story and about as useful as a marketing sheet.

ASR's reviews are a tool, and measurements, if you understand what they mean are essentially irrefutable evidence taking in the context of how the test was administered.

To sum up however because Cindy will be along shortly to tell everyone what's what.

Gotta love it when your reputation proceeds you ....

Let's do a thought experiment:

I make a DAC. The DAC has a SD memory card on which there is music. The DAC of course reads the music from the memory card, puts it in a buffer, and then plays it out. What impact does the SD card have on the quality of music assuming it is not broken? None. I think most would accept that. If someone does not, then an reasoned discussion is impossible.

Now let's say I have a cheap server or expensive server/streamer, and it connects to my DAC. It does it using USB or Ethernet. The DAC just like above, reads the data (perfectly), and puts it in a memory buffer?  How is this at all any different from the above? From the data side none. They both get perfect data.  One one and singular difference is noise. So now we know the difference between a SD Card, a NAS/Computer and an expensive streamer is purely noise.

Ethernet:  This is already electrically isolated. There is a transformer on each end.  That is pretty effective noise isolation. Being Ethernet, you can place your hardware a distance away if you are worried about AC noise, and/or buy one of many AC filters.  If you are still worried, there are Ethernet filters that claim to remove unnecessary frequencies from Ethernet  (keeping in mind you already have two isolation transformers).

USB: Direct electrical connection, hence high potential for ground noise. No worries, a really good USB isolator is about $300, maybe $400 with a linear supply. I hear Topping has one <$100 now. Optical isolation. No direct noise path. You have some distance limitations.

What are you missing? Nothing. You seem to understand the basics just fine.

The oft repeated saying "The chain is only as strong as its weakest link", sounds nice, but wrong. How about looking at it another way. If the chain does not break, then it does not matter if any of the links are stronger of weaker. It is good enough to do the job. But that is still wrong because it is not a mechanical chain, it a processing chain.

NAS = -40db noise, DAC-A = -80db rejection - final result = -120db

High End Server = -60db noise, DAC-B = -50db rejection - final result = -110db

Well what do know, it is not about the weakest link, it is the combination. But frankly it does not matter, you would not hear something -110db or -120db noise with music playing .... the chain is more than good enough.

TEST A: Plug / Unplug Ethernet with the volume at the max of the listening level. Do you hear any change in noise? No, then you don't have an analog noise issue.

TEST B: ... really there is no test B, because the next claim will be "well what about digital noise hurting the clock". Well if the analog noise is so low that you can't detect it or super faint, what are the odds it is impacting the super fast transition of clock signals that are at least 1V?  The noise from the internal circuitry in the DACs digital section is likely orders of magnitude higher than external sources with Ethernet or isolated USB.

@alexb76 

People are still making claims about digital that have not been true for decades. This is just one of them. There used to be problems with jitter on TOSLINK, but then just don't use it. The rare time you may get jitter on SPDIF if poorly implemented, but then just change the cable length. Noise on SPDIF is a potential issue, so buy something with transformer isolated SPDIF. USB can present electrical system noise, so isolate it. Hard to comment on Ethernet noise. Many claims, nothing to indicate any level of testing. Theoretically possible, so if you feel the need add a filter.  Computers can have noisy power supplies, but then again, linear supplies create awful harmonics on the AC line with lots of current/power. But you can remote your hardware or buy a filter.

Agreed, items like Innuos are simple, and make sense for many audiophiles. Time is money, and most don't have the experience. A lot of the reticence of using PCs as streaming sources is not just USB, but inability to set up the system so that you got bit perfect, and Windows or OSX was not inserting sample rate conversion, limiting, etc. in the middle.