We Need To Talk About Ones And Zeroes

@mswale, I agree with you.

@jsalerno277  you wrote:

Your minor premise is that these digital packets successfully travel thousands of miles through AWS’ digital sewer, only to arrive in our homes completely unscathed ones and zeroes.  Facts prove this premise false.  The transmission of digital data over the WWW introduces a number of errors that cause distortion including, without limitation:

1. Jitter, the distortion we are all most familiar with. ​​​​​​
2. Transmission impairments: signal distortion, attenuation
3. Noise:  From EMI which includes RFI, introduced during transmission.

Your statement is incorrect.  The 3 bullet points impact the "signal" at the digital to analog stage.  Not during the digital to digital transmission.

I’m a computer/network/server guy with over 40 years experience in the field.  I was working with networking systems when "ethernet" was still using coax cable and what we call the Internet (i.e. World Wide Web) didn’t even exist yet.

All network transmission protocols, such as TCPIP, Netbios, etc., whether through the Internet, on a corporate LAN, or on your residential WLAN/LAN, have safeguards built in.  They are designed to insure that the data transmitted and received at either end is correct, bit by bit.  If there is any descripancy, it will request that the data packet be resent over and over again, until it is right.  Even a CD player has safeguards to guard against read errors, it’s called oversampling.  (Something nobody even thinks about anymore since it is so reliable.)

And think about it for a minute.  If the data stream is even a little bit wrong, even one bit of data flipped from a 0 to a 1, it would cause corruption that could be a financial transaction to be wrong, or a database to contain the wrong information, or a music file to be corrupted.  And once the data has been digitized, the network transmission/receipt doesn’t differentiate between the type of data (i.e financial, video, scientific, or even music), it is just a string of 0 and 1’s.  That is the beauty of digital transmission.  What is sent is what is received.  And you should be thankful that is correct, otherwise you might find the decimal place on an online credit card transaction to be one place to the right of where it should be.

Jitter, EMI noise, data buffers running dry do to slowness, etc. don’t affect the correctness of the digital data. They effect the ability of the D to A processor and software to convert it back into an analog output.

@devinplombier - I usually stay out of these conversations because they always seem to go sideways and inevitably lose the point of the original post.  But today I have stepped into the fray....

So, here is my take on things...

I agree with your overriding idea for the post.  The topic is full of assumptions, misconceptions and lack of understanding.  Even after my 40 years experience in computers, networking, servers, and software in multinational manufacturing companies, I’m still guilty of them at times.

Looks like a number of folks agree that the digital audio file that "lands" in your streamer is an exact, bit-perfect copy of the file Qobuz sent you, and of the file coming out of your CD or SACD of the same, assuming resolutions match and they originate from the same master.

Correct.  Digital files, whether complete files or data being streamed should always match between source and destination.  If it doesn’t then the data is corrupted and dies.  Files are unusable and streaming data packets are unable to be converted to an analog signal.

A lot of folks seem to confuse digital files (made of ones and zeroes) with digital signal (the analog waveform representations of said ones and zeroes on transmission lines) and undesirable (but analog) noise that might travel along over said transmission lines.

You are correct about the confusion.  So, let’s discuss the noise that travels over transmission lines.  There is noise, and bottle necks, and delays in transmissions, and even packets taking completely different paths across the Internet to get to the destination.  (Welcome to TCPIP and the original design of the ARPANET, the core of the Internet and many wide area (WLAN) modern networks.)

So, what is the affect of all the general "noise".  Typically it only will cause delays in packet transmission and receipt.  The protocols in place are designed to assure the data comes through "unscathed" (and yes, I’m using that word on purpose), even it if requires a lot of time, possibly to the point of timing out and the connection getting dropped.  And there is one of the rubs, speed of data flow.  More on that in a minute.  But first, it needs to be noted that the "noise" present across any transmission/receiver leg ends at that receiving hardware.  This would include the legs from the original server to network switch, network switch to firewall, firewall to router, router to your ISP, your ISP to home modem, home modem to network switch, or network switch to streamer.  Why is this true? It is because the data always travels in packets, not in a start to finish steady stream like an analog signal.  So each leg starts off with a complete packet and that packet is clean and isolated from the previous leg.

Now back to the rub of the data flow speed.  This is where somethings can go wrong. In the case of a sequencial "streaming" of data, whether being video or audio, eventially the data packets need to be sequenced and converted to a continous analog signal. (BTW, I’m trying to keep this very simple...)  And here is where time comes into play.  If there are delays in receipt due to noise or packets coming into the buffer out of order, the data won’t stay ahead of the requests from the processor.  And thus you get Jitter.  

Now, how would Ethernet gear located in the last 10 or 20 feet (aka your home) of that file’s 3000-mile journey somehow manage to compromise it where AWS itself failed?
Why would a simple $18 Monoprice Ethernet switch affect a digital audio file unaffected by a trip through hundreds of super-noisy industrial-grade switches...?

One misconception in the statement above.  "super-noisy industrial grade switches".  These industrial grade switches are designed to route the data packets in high volumes and with minimal requests for packet resends.  The onboard software control is significant and monitored (i.e. level 3 managed switches).  They have large data transfer backplanes and these days are running at 10 GB upwards of 800 GB ethernet speeds.  Your home networking equipment typically maxes out a 1 GB.  Any noise inside the circuitry is negligible in this discussion.

Then, to the question of how can the last 10 or 20 feet in you house have an impact.  First, the hardware is cheap and relatively slow.  Enterprise level network switches, like what AWS is using, can run up into the $10K plus range.  Routers and firewalls used by corporations and ISP’s in the same range, or even higher.  Your home modem and network switches, a couple of hundred bucks.  In fact, they are actually noiser than Enterprise level equipment.  Second, power supplies.  Typically, home equipment use power supplies that are barely enough to run the equipment.  Start loading it down with constant data flows, and they start to fade out, speeds drop, induced noise goes up, packet resend requests rise and things go boom on the receiving end.  Third, shielding.  Enterprise level equipment is usually in metal cabinets.  Power supplies are shielded internally.  Processors and buffer memory as well.  Most home modems/routers/ and switches, not so much.

What can reasonably be hoped to be achieved by swapping in a $700 "audiophile" switch, all power supplies being equal?

Honestly, power supplies outstanding, I have no idea what some of these companies do to create an "audiophile" switch.  I have seen a few that have been opened or completely torn down, and other than a different paint job, they seem to be typical home equipment.  Just slap a different power supply in, call in audiophile, and charge a $400 markup.  I don’t know.  All I know is that my Enterprise level Cisco switch in my basement will out perform it.

Thanks if you read this all the way though.  I know I written a a novel.  Time for bed.

- Jeff

@cleeds -  I haven't done much with switches labeled as "audiophile" grade.  So, as I indicated, I don't know what they have all done inside other than changing out the power supply.  Some may be completely reengineered and use top notch jacks, power supplies, etc.  I honestly don't know.  Did I overstate my home network with Enterprise level Cisco equipment, yeah, maybe.  It was late and I was tired when I wrote it.

My home network is running on Cisco C3850 layer 3 switches (over $5K new) setup with VLANs and QoS (quality of service) to segment off my streamers from the rest of the network (i.e. desktop and laptop computers, WiFi access point, Amazon Echo devices, printer, etc.)  My router is also a Cisco Enterprise level appliance.  I picked up the equipment at an auction of a local failed business.  Unfortunately, the cable modem is a typical Motorola that is supported by my local ISP.

The only "audiophile" switch I have actually compared against my setup was an English Electric 8 that a friend purchased from Upscale Audio.  With a "stock" wallwart power supply, and pushing the data volume way up on multiple ports, it was not matching my Cisco setup.  According to management/diagnostic software, it was dropping packets at a much higher rate than I would have expected.  Sound wise, it was ok. Once I changed out to the "better" power supply that came with it, things improved dramatically, both in network performance and sound quality.  But still it did not perform better than the Cisco setup.  If I were to make a guess as to why, I would say the larger and faster backplane of the Cisco and segmenting the ports into VLANs was creating a more stable data stream to my main streamer(s), even when loading it down and taxing it's capacity.  And thus a much lower level of jitter and smoother processing.

I referenced that I have seen pictures of the internals of other audiophile switches.  I remember one that turned out to just be a Netgear GS series 8 port switch in a different colored case with a linear power supply.  Another was a DLink that was supposed to have been "modified" but only had some stuff glued to the top of some caps and chips and was marked up 500%.  And then another that was just a  Linksys that was repainted and sold with a SBooster power supply for high dollars.  

@hbarrel -

they appear error-free to users because of sophisticated error detection, correction, and redundancy mechanisms built into the system. Here’s how they ensure high reliability despite the presence of noise...

Exactly!  This is the key to any digital network and why it actually works, whether it is a financial transaction, email, video feed, or music.  What you transmit in the beginning is what you get at the end. 

@curiousjim 

I guess parts is parts and pieces is pieces and it don’t matter in what order they go cause it’s all gonna sound the same.

Simply...No.

Most of the conversation so far has been on digital data transmission and receipt.  While the fundmental design of a digital network insures that what was sent ends up being the same data at the end, factors such as the effect of the noise floor on creating data packet resend requests, can effect the timing of the data feed at the final end point.  (In this instance, the network connection at the streamer.)  

What hasn't been really talked about yet is how all the hardware and software "parts and pieces" come into play.  One goal is to reduce (or isolate) the noise floor on the data transmission by using good hardware/software, like adequate power sources, quality connectors and wiring, capable networking equipment, etc. Reduce the noise floor and, hopefully, reduce the data timing difficulties at the end point.  Thus it changes the sound (hopefully for the better.)

Then there is how all the parts and pieces come together after the final network connection at the streamer and/or DAC.  Then the circuit design, the parts chosen, software operating system, firmware, DAC chips, shielding, power supplies, etc. all come together to take the digital data stream and convert it to an analog signal.  Doing this well can be difficult. And it is where the greatest differences in the "sound" of a streamer/DAC come from.

And then you get to enjoy all the different types of chicken nuggets from places like McDonalds, Taco Bell, KFC, and Bojangles.  Same chicken, different receipes.  LOL.

-Jeff

@cleeds 

I having to remember and Google.  It was a few years ago.

The modified DLink was an Aqvox.  I remember that because there was a Linus Tech Tip on YouTube that did the tare down.  I also seem to remember there was a Paul Pang modified DLink that was somewhat dubious (I had to Google this one for the name.)

The Netgear may have been one of the early Silent Angel switches, but don't hold me to that.  

And the Linksys, no clue anymore.  I just remember the pictures because they painted the case a matte black and didn't even mask the open ports properly. On top of that, they just pasted their sticker over top of the Linksys sticket on the bottom.