[Bill]

Plays Real Basses wrote:
Scott Dorsey wrote:
anahata wrote:
I take your point, but I'm suggesting or assuming that an amplifier
rated at 500W into 2 ohms will have lower output device resistances
than a different amplifier rated at 500 W into 8 ohms.

This isn't a good assumption to make. In fact, the two could even be
the same amplifier!

A typical amplifier rated at 500W into 8 ohms should also be rated 2000W
into 2 ohms, and therefore ought to have _lower_ device resistance than
an amplifier rated at 500W into 2 ohms.

Unfortunately many don't. Which is why a lot of amplifiers rated 500W
into 8 ohms are only rated 1500W into 2 ohms... where is that other 500W
going? --scott


HEAT...

For raw power, one of the new things coming out of the chip
manufacturers labs is PWM, or Pulse Width Modulation so that the output
transistors are either fully on or fully off. So far they have it
working with low power audio and are thinking of making it standard in
cell phones to save even more power. No fidelity there though.
I did a project with it a few years back for motor control with an
output bandwidth up to 1KHz and distortion was not an issue there but I
was putting out about a hundred watts with a 50KHz pulse frequency and
very little transistor heat. I don't know if any manufacturers of high
power audio will try to go that way for a while, but I have heard it
mentioned for consumer audio equipment up to about 50 watts.
Right now, it is a wait and see.
Bill Baka