I need help on directionality of speaker cables

As far as I'm aware, the output stages of CD players, tuners and preamps is DC. That's why the power supplies of such devices turn your wall outlet AC into low voltage DC to do their work. It's only at the output stage of the power amplifier where the signal becomes AC again, as it must to move the voice coil back and forth like a piston in your speaker.
Given that the negative outer ring of the in & out RCA sockets on amps etc are all connected to the chassis (earth), this says to me it must be a DC circuit. I'm yet to see the (-) of a speaker terminal on the power amp earthed to the amp's chassis.

Turntables, by virtue of their moving magnet or cartridge are basically a speaker in reverse (as is a microphone) hence their AC output.

Analog and AC are unrelated terms.

My post wasn't meant to sound arrogant, it was more about the apparent muddling of AC and DC in some posts, and less about the detail of what each component does. As always, I am happy to be set straight by an EE if the above is wrong.

Carl, all signals in analogue are AC and therefore non directional. Circuits containing capacitors and coils cannot function on DC, they need the current to alternate at different frequencies to do their jobs.
The ouputs from digital device are simply a series of numbers that are decoded into an analagous AC signal to be amplified before being used at the speaker.

I am not an EE (I am a Chemical Engineer, actually), but have had an interest in this hobby for over 40 years and looked over many a circuit diagrams and can assure you that analogue circuits indeed carry Alternating Current, the frequency varying, of course, according to the signal being carried, thus the term Analagous.

Respectfully, Bob P.

Carl:

My post wasn't meant to sound arrogant, it was more about the apparent muddling of AC and DC in some posts

I got it, I think. You must have read s/where that AC is converted to dc in the power supplies...
However, the electrical signal the devices output is AC as is the input of course. Inputting DC into any of these devices is *dangerous*!!

If analog audio is AC, then doesn't that also defeat the purpose of direcional arrows on interconnects as well as speaker cables?
My understanding was that audio signals could be carried as DC, but that AC was required for speakers to allow them to vibrate in piston fashion.

I can see I'm going to have to have another discussion with my info source (a digital engineer) to straighten out my knowledge!

I humbly backpeddle for my previous grandstanding...

Ryder, The stream of information is not AC and not analagous to the voltage information before encoding into digital, i.e. numbers. The numbers (information) are carryied to the next stage and then decoded back into an analagous varying voltage + or - and amplified to drive the speakers with AC current.
Bob P.

Bob, please treat this as a healthy discussion.

I am confused by your explanation. We all know that the bits are in ones and zeros(information). The question that remains is whether there is current flow in the cable. I have read from sources that AC current do flow in digital cables. Before this I had known that there must be some current to transport those bits(information) to the next stage.

Your argument is that AC is non-directional. If that's the case, how do we explain on the findings by Robert Harley in Stereophile? My logic is simple. If what he wrote is true, then this will apply to speaker cable as well. By the way, it's AC current in speaker cables am I right?

I would be glad as well if any EE would care to clear things up for us.

To the interest of the original poster, if you would care to google on "cable directionality", there are quite a few sites that touch on this article, mostly cable manufacturers. It's interesting to note of Russ Andrews claim of having verified the benefits of cable directionality with their engineers using advanced equipment and technology, but unfortunately didn't provide any technical evidence to back that up.