Defining and diagraming the audio chain

BradJudy · « **on:** 5 Mar 2009, 05:18 pm »

I was playing around with diagrams for this thread over on Head-Fi and taking the chance to educate myself a bit more on various matters. http://www.head-fi.org/forums/f46/before-asking-about-digital-audio-read-digital-audio-primer-410022/

In working on diagrams, there are some items with clear definitions (DAC, amp, pre-amp, etc) and others where commonly used "audiophile" terms don't seem to have as concrete of a definition (source, transport, etc).

Transport seems clear in the optical disc world - a CD/DVD player that outputs a digital signal. What about in the computer world where there are multiple forms of a digital signal internally and externally (digital out from internal soundcard, external USB transport, etc). If you're using a USB to SPDIF box, where is the boundary for the "transport"? Are there two "transports" (the computer outputting USB and the USB device outputting SPDIF)?

The word "source" seems ambiguous in general. Sometimes it's used to mean everything upstream of the pre-amp and sometimes it seems to mean a particular component. The OP of that thread suggested it was whatever piece read the static content into a digital signal (or presumably analog signal in something like a turntable setup). Of course, there's an argument to be made that the word "source" might not have a place in this type of diagram.

If your goal is to help newbies to understand the chain, the components and their roles, what would you tell them?

BTW: I'm not sure how much detail is best, but since pieces of DACs are often discussed, I did a break-out for the above diagram and it's missing key pieces like a clock (which also gets a lot of discussion).

Bob in St. Louis · « **Reply #1 on:** 5 Mar 2009, 06:10 pm »

Great diagram Brad.

I did a simular one a while back on Windows "Paint" (during a boring day at work). The "monster" had grown to the point where it was getting hard to explain what all it's capable of and how it's all wired. It's too small and hard to read, but I can't figure out how to tell Photobucket to make it any bigger.
It's a ~~little~~ LOT outdated as I've added several more components in the system, but here's mine:

Ethan Winer · « **Reply #2 on:** 5 Mar 2009, 06:17 pm »

Quote from: BradJudy on 5 Mar 2009, 05:18 pm

If your goal is to help newbies to understand the chain, the components and their roles, what would you tell them?

I would tell then that what matters most are the loudspeakers you use and the room you listen in. Everything else is in the bottom few percent. These days even modest electronic gear is very good. Versus +/- 5 dB or more for speakers, and +/- 15 dB or more for rooms, especially at bass frequencies.

--Ethan

Don_S · « **Reply #3 on:** 5 Mar 2009, 07:14 pm »

Duh, I think I know what I am doing but if I was a newbie I would be intimidated by either diagram.

Realize that many users don't have a transport + DAC or preamplifier + amplifier. They use a CDP and receiver or integrated. Nothing in the diagrams help them choose a component or speakers which I suspect is their primary concern.

Brad and Bob, are you engineers?

BradJudy · « **Reply #4 on:** 5 Mar 2009, 07:31 pm »

I know many users don't have specific components. I mocked up a series of configurations that include different types of components. None of the rest of the diagrams contain the DAC break-out, making them simpler. I figured the highly technical and detailed crew here would want to see the more detailed picture to accompany the discussion of what is a transport/source. Here's another, simpler, example:

The point of the discussion and diagrams isn't to help people choose what component is best. The idea was to help people understand the terms being used and how something like a DAC may reside in any number of places in a digital chain, but every digital playback chain has one somewhere. And how an integrated device like an iPod contains all of these components.

Bob in St. Louis · « **Reply #5 on:** 5 Mar 2009, 07:32 pm »

I'm not Don.
What you see (on mine) is simply the result of a fellow trapped at work bored out of his mind.

Bob

Don_S · « **Reply #6 on:** 5 Mar 2009, 07:36 pm »

Quote from: Bob in St. Louis on 5 Mar 2009, 07:32 pm

I'm not Don.
What you see (on mine) is simply the result of a fellow trapped at work bored out of his mind.

Bob

I understand that one Bob. That is why I retired very early. I was either bored to tears or the point end of the spear. Neither was much fun. Of course it would be a lot nicer if I was being "paid" to type this response.

Bob in St. Louis · « **Reply #7 on:** 5 Mar 2009, 07:39 pm »

Quote from: Don_S on 5 Mar 2009, 07:36 pm

Of course it would be a lot nicer if I was being "paid" to type this response.

You got it Brother.

Bob

Ooops, there's another dollar.

Speedskater · « **Reply #8 on:** 6 Mar 2009, 01:11 am »

AV Snap has a nice diagramming program.
It's still under development.

http://www.avsnap.com/

Wind Chaser · « **Reply #9 on:** 6 Mar 2009, 01:16 am »

Quote from: Ethan Winer on 5 Mar 2009, 06:17 pm

Quote from: BradJudy on 5 Mar 2009, 05:18 pm
If your goal is to help newbies to understand the chain, the components and their roles, what would you tell them?

I would tell then that what matters most are the loudspeakers you use and the room you listen in. Everything else is in the bottom few percent.

+1

low.pfile · « **Reply #10 on:** 6 Mar 2009, 09:02 am »

OK back to diagram methods. there are dozens of standard formats. I never use them.

BradJudy I think its best to provide some hierarchal schemes in a diagram (e.g. the DAC is part of a component)

I also found simplification really helps make one diagram communicate more than others - but not down to bare bones. Bare bones tends just to show that things ARE connected. But now why or how. Color coding and or spacial layout do help to group and or show hierarchy. Also by simplification I mean not including every aspect of a device.

Always ask is the diagram work without any additional written text or verbal presentation.

I have only one old friend back home who I really talk Audio Video with and I started a diagram to show how crazy my setup morphed into since our receiver/ cd player/ bookshelves systems from years back -into a computer based system with wireless control. First I did it literally showing items per room and control methods. A month later I wanted a diagram to show less about the whole house and just show the system components (the system also changed) Then later after completing the second diagram I asked the question what exact question was I trying to answer. And the question was "what is used for 2ch music and what for HT 5.1?" I did the third version in a short time ( <1 hr). It's not perfect but I felt it was more successful than my prior version in better communicating the specific info intended.

Version 3:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Version 2:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Version 1:

Lots of ways to get the job done. Have fun.

cheers, ed

nathanm · « **Reply #11 on:** 6 Mar 2009, 04:17 pm »

BradJudy, low.pfile: Just curious, what software are you guys using to make these graphics?

BradJudy · « **Reply #12 on:** 6 Mar 2009, 04:19 pm »

Quote from: nathanm on 6 Mar 2009, 04:17 pm

BradJudy, low.pfile: Just curious, what software are you guys using to make these graphics?

Mine are just in PowerPoint. Typically I would use Visio for diagramming, but PowerPoint was quicker for something simple like this.

low.pfile · « **Reply #13 on:** 6 Mar 2009, 04:24 pm »

Nathan,
I always use Adobe Illustrator.
ed

BradJudy · « **Reply #14 on:** 6 Mar 2009, 04:25 pm »

Ed - I like the third version. It's a nice, simple and clear diagram for the components of a two-purpose system.

BradJudy · « **Reply #15 on:** 6 Mar 2009, 04:33 pm »

Apparently posting diagrams got everyone completely distracted from my core questions. I should know better than to dangle a shiny object while asking questions.

I'll try re-asking in here and if it does work, I'll try a new thread.

How do you define "source" in the context of hifi audio? Is it the content (as in "source material")? Is it where the analog starts in a signal path (DAC, turntable, etc)? Is it wherever the content becomes a signal (transport, truntable, etc)? Or is it just a term that isn't concrete enough to be useful in explaining how an audio system works?

How do you define "transport" in a computer based rig? Is it anything outputting a digital signal (regardless of format) or only something that puts out a standard digital audio signal (like SPDIF)?

Bob in St. Louis · « **Reply #16 on:** 6 Mar 2009, 05:20 pm »

Quote from: BradJudy on 6 Mar 2009, 04:33 pm

I should know better than to dangle a shiny object while asking questions.

Sorry Brad. Looks I got the discussion started off in the wrong direction. I apologize for being the one to lead the pack astray.

Back on track.......

Source:
I would define it as the "root" of the music; Where it comes from, or where it originates.
Here's a few applicable wiki definitions that work well for audio;
- A facility where something is available (think; Library, warehouse etc...)
- Anything to the right of an operator on a dependency line (I like that one. Works well for audio).

I wouldn't define 'source' as "where the analog starts in a signal path ", as there are digital sources.
Personally, I'd call it the origin of the music; Turntable, CDP, HDD, cassette deck, VCR, etc...

Bob

martyo · « **Reply #17 on:** 6 Mar 2009, 05:30 pm »

I've always defined source as the source material. A Cd, or DVD, an album, a Flac file......Not a piece of Hi-fi equipment.

BradJudy · « **Reply #18 on:** 6 Mar 2009, 06:27 pm »

Quote from: Bob in St. Louis on 6 Mar 2009, 05:20 pm

I wouldn't define 'source' as "where the analog starts in a signal path ", as there are digital sources.
Personally, I'd call it the origin of the music; Turntable, CDP, HDD, cassette deck, VCR, etc...

This is a definition I was considering, the item that takes "static" content and makes it into some sort of signal (whether it is digital or analog).

BTW: This definition gets interesting in the computer world. Presumably the "source" is the application that reads the files and sends a digital stream to the next link in the chain (foobar, Winamp, iTunes, SqueezeCenter).

BradJudy · « **Reply #19 on:** 6 Mar 2009, 06:37 pm »

Quote from: martyo on 6 Mar 2009, 05:30 pm

I've always defined source as the source material. A Cd, or DVD, an album, a Flac file......Not a piece of Hi-fi equipment.

In the HeadFi thread, there was an argument made that "source" has a concrete definition in the pro audio world as the content, and that using other definitions would be confusing.

While I agree that differing definitions is confusing, a quick look at the "for sale" sections here and at HeadFi show the common usage of "source" to indicate a piece of hardware used for playback. Stereophile categorizes items under either "digital source" or "analog source", although I couldn't find a definition of "source" or "transport" in Stereophile whitepapers. Neither Audiogon nor Audio Asylum use the term source as a category.