Digital, but not by the numbers

[magnoman]

Originally Posted by marce

...
One would hope that high end digital equipement has proper multilayer boards (12-14), which is what PC's should have as a minimum, a lot dont though...

Marce,
Can you give me some insight into why 12-14 layers, how does this number compare to a circuit which is not very signal intensive (i.e. from a connectivity point of view could easily be done on 2 layers).

Or of these 12-14 layers how many are needed for just trace routing, how many are planes.
I'm sure it's complicated with impedance control and cross-talk and low Z power distribution, etc but just some rough idea's would be helpful.

Thanks
-Antonio

[marce]

they could wind the handle as well

[regal]

Those old tube computers are a perfect example of the common misconception that digital is discrete (on or off) in practice, obviously the vacuum tube diodes used in the computers back then and the transistors used to transmit digital signals now are "analog" or continuous in the transition from what is defined as on to off. That doesn't mean that digital theory isn't practical just that its easy to fall into the trap of confusing a mathematical abstraction with physics Discrete just doesn't exist in nature, its the Heisenberg Principle. Just think how much better off we would be had Sony/Phillips execs grasped that simple concept before sticking us with spdif for the last 30 years.

Oh well as of today we have Internet Explorer 10 and I get automatic spell check when posting here, so digital isn't all bad

Really I haven't played an analog tape or vinyl in 20 years, digital can be fantastic you just have to cheat

[qusp]

Originally Posted by marce

they could wind the handle as well

that was the idea answering phonecalls and emails is just a fringe benefit

[Julf]

Originally Posted by regal

Those old tube computers are a perfect example of the common misconception that digital is discrete (on or off) in practice, obviously the vacuum tube diodes used in the computers back then and the transistors used to transmit digital signals now are "analog" or continuous in the transition from what is defined as on to off.

Well, their predecessors are even better examples. They used relays. Relays, especially small signal ones, really are discrete - on or off.

Again, digital circuits use analog components in a digital way, to transmit and process discrete, binary signals. That is done by requantizing, resyncronizing and regenerating the "analog" signal so that it becomes digital again - truly just on or off.

Digital circuits, at the level of digital circuits, are really discrete and purely digital.

Talking about things lie s/pdif is confusing the issue, because s/pdif isn't a digital circuit, it is a transmission system. Transmission systems are, on the level of the physical media, analog, but again, get re-digitized in the receiving circuitry.

[DF96]

Vacuum tube computers are no more and no less analogue than a BJT-based computer or a CMOS-based computer. Provided timing is not an issue and the computer is well-designed then it really is digital, as far as the logic goes.

Digital audio interconnects are a separate issue, as there is a timing aspect too.

[Julf]

Originally Posted by DF96

Vacuum tube computers are no more and no less analogue than a BJT-based computer or a CMOS-based computer. Provided timing is not an issue and the computer is well-designed then it really is digital, as far as the logic goes.

I guess we can keep repeating it until we are blue in the face. Unfortunately "digital is really analog" is such a nice soundbite for the "everything matters" crowd... Who cares if it is true or not, it *sounds* good...

[DF96]

Then there is the Hawksford fuzzy distortion idea, which could be summarised as 'analogue is really digital'. (He is wrong, as he ignores electron correlation).

[fas42]

Originally Posted by Julf

I guess we can keep repeating it until we are blue in the face. Unfortunately "digital is really analog" is such a nice soundbite for the "everything matters" crowd...

Implying there is a "not everything matters" crowd ... hmmm, only have to get half the issues sorted out to get fantastic sound; plenty of time left then to sink a few beers, that mightn't be too bad, might hop across there for a while ...

Frank

[Julf]

Originally Posted by fas42

Implying there is a "not everything matters" crowd ...

Absolutely - I am definitely in the "if I really can't hear any difference and measure any difference, why should I spend a lot of money just because some 'audiophile reviewer' who gets paid to promote products tells me I should?" camp.