pil wrote:

"Joerg" wrote in message
...
Johan, I don't know these or many other audio books. Just one hint:
Nowadays I
would certainly try to learn about class D audio amps, the digital kind.
That
seems to be where technology goes.

Regards, Joerg.



Good thing you mentioned that. I always wanted to know this: What is the
difference between digital and analog?

How can a digital signal be amplified???
How can a one become a louder one?
And most important to me: How can you drive a speaker with a digital
signal???

As far as I am concerned every "digital" hi-fi must still have an analog
amplifier somewhere in its design. The amplified speakers (which they claim
to be digital speakers) has a DAC and a normal analog amplifier right?

I would greatly appreaciate answer on this

No. Digital audio (class D) treats the speaker current like the
output of a switching regulated supply that has AC capability. There
is nothing but two levels coming out of the speaker terminals, except
for the effect of filtering components.

A good intro to this kind of amplifier is the datasheet for one of the
integrated versions.

http://focus.ti.com/lit/ds/symlink/tpa3001d1.pdf
--
John Popelish