I need help on directionality of speaker cables

04-29-07: Carl109
>>"No offence, but I think a few members really need to do a bit of basic reading on electronics to understand AC and DC current."<<

>>"Without getting bogged down here, DC (direct current, or fixed polarity) is what takes the information from source to preamp, preamp to power amp, down digital cables etc."<<

Unless I misunderstood something, isn't "analog" audio signal A.C. (~) from source to preamp, and preamp to poweramp?

Carl -- what on earth are you saying? Surely not that there's dc output from yr source I hope -- you risk blowing yr amp.
You must mean s/thing else.

BTW, the mains does have phase, neutral & ground. It also has a frequency, remember -- 50 or 60Hz.

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*!!