Re: minimal good amplifier for JBL L80T speakers?

"jamesgangnc" <jamesgangnc@[EMAIL PROTECTED]
> wrote in message
news:956a9439-ef66-43e7-b393-65da4bd370c9@[EMAIL PROTECTED]
> Compare the rms watts rating when shopping for amps.
> That's the only rating that is fairly consistently
> measured across the board.

Except it isn't. Usually in the bold print they use different amounts of 
THD. An amp that puts out 80 watts at 0.02% THD puts out something like
100 
watts at 0.8 THD and 150 watts at 10% THD.

>  Beware of ratings that seem
> outlandish because they probably are.  When the salesman
> tells you a surround sound receiver has something
> outlandish like 5 or 600 watts he is talking about some
> sort of "peak" power.

Surprisingly, these surround receivers actually do put out 100 watts RMS 
each for all 5 channels concurrently, or 85 watts RMS each for 7  channels

concurrently.

> Just look at the power cord, is it the size of a lamp cord?

Probably a 10 amp cord. They have high temperature and thinner insulation
so 
the cord can be smaller without melting.

> To get 500 watts out you have to put at least 500 watts in.

Agreed. More like about 700 watts.

>  Look at any decent top end amp.

One place more expensive amps get their need for heavier cords comes from 
their ability to put 50-70% more power into a 4 ohm load then an 8 ohm
load. 
The receivers usually put more like the same power into both load 
impedances. That cuts back on the current drain quite a bit.

> Even the ones with less that 100wpc rms will have a hefty
> power cord.  Also you want a class ab amp.  Not one of
> those "switching" amps.

There aren't a lot of switchmode amps among the popular-priced receivers. 
Switchmode still costs more money to implement, and the over-all power 
savings aren't all that wonderful.