"Roko" wrote in message
Hi all,
I'm new here, and for starters I have a really noobish
question:
Why exactly is it impossible to connect HiFi Speakers to
a computer (except because of the fact that they don't
have a mini-jack plug 
(at least mine don't) )?
Most computer sound cards are designed to drive headphones and speakers with
their own power amplifiers built into them.
I know it's possible to connect a computer to a HiFi
system (by plugging it into "Line In"/"AUX"), but I would
like to be able to do it without the Hi-Fi system, only
with the speakers.
This won't be sucessful.
I guess what I really want to know is what kind of a
'converter' is there inside the Hi-Fi system..?
The "converter" is called a power amplifier.
Does it
modify the signal from the computer, or is it merely a
small circuit just adapting the
amperage/voltage/impedance/whatever..?
These things vary, but at the minimum they are fair-sized circuits that
adapt the amperage/voltage/impedance, as you put it. Their size is
nontrivial because of the power levels that are involved.
It turns out that most desktop PCs have fairly healthy internal 12 volt DC
power sources that have considerable reserves. Power amplifiers of the kind
that are used with automotive sound systems (which are designed for 14.7
volt power) can be adapted to exploit this source of power.