Stream buffering and Audiophile Network Devices

This is yet another "this subject comes up so often I'm going to monetize it" post! 

In this case though I'm going to encourage you NOT to spend money. 

Audiophiles attempt to optimize the last 30' of what is hundreds of miles of journey of a stream, say from Qobuz, or Tidal or even Amazon or Netflix.  They spend hundreds of dollars, if not thousands of dollars on "audio grade" network switches that promise noise elimination, jitter elimination, etc.  

They're all pretty much useless.  Let me give you a working metaphor. 

Imagine you have a factory which makes cardboard boxes pre-filled with Styrofoam peanuts.  On one side of the factory you receive the flat boxes, and peanuts and on the other you put out a 1 cubic foot box filled with peanuts. To extend this metaphor to our needs, the factory MUST produce 1 box every second. 

This is, of course, a metaphor for an audio streamer.  Network packets arrive on one end with music data, and an analog signal is produced on the other.  Among many other variables, the DAC must interpret a single sample at precise intervals in order to minimize distortion and jitter.  For PCM data these samples are usually 16 or 24 bits long.  Every clock tick consumes one sample and sets the DAC's output to a new voltage which is connected to your amplifier or preamp.  Where audiophiles go wrong is they think that this output is on a chain, and married to the rate of the input packets, like a bicycle's gears.  It is nothing like that.

We'll return to our metaphorical box factory.  Every six hours a shipping truck arrives with at least six hours of cardboard boxes and peanuts, but it can go up to 12 hours worth.  It depends on when the factory ordered, and how much free space is in the warehouse. 

Now imagine that the delivery trucks must pass many roads and toll bridges and traffic lights but just outside the factory the traffic light there uses a cesium clock of extreme accuracy so that the light changes from red to green only exactly every 120.0000000000000000000 seconds.  In a thousand years this clock may be off by 1 second. 

This is what network reclockers/regenerators offer you.  Absolutely nothing.  So long as the trucks keep arriving near schedule, even when delayed, the factory still produces filled boxes once per second and are completely insensitive to the clock of the traffic light outside the factory.

What about master clocks?  

It's a fact of physics and digital data transmission that the single best place to put an oscillator is on the same circuit board as the DAC chip itself.  Benchmark Media, Mytek and others have correctly written about this, and, correctly compared this to the maximum distance computer memory can have from the CPU.  The further the distance the less sharp the transient edges can be and the lower the precision. 

In music and film production master clocks are used not to reduce jitter but to synchronize multiple systems at once.  A good example is in movie production, ensuring that the audio track is precisely timed to the video, but this can also be needed when using multiple synthesizers and effect systems.  

Using an external master clock for playback can certainly change your jitter performance, but all things being equal, you want your best clock millimeters away from the DAC chip.