Practical audio amps
"Neil Gould" wrote in message
...
RANT
Every now and then, I look at new amp offerings to cover the "what-if"
scenario that my aging BGW amps will need to be replaced. I'm finding
fewer
and fewer amps in the under 100w/ch range. Also, the newer amps either
have
horrid THD (1%... really?!) or exorbitant pricing. Or both. Have speakers
really become so inefficient that one needs 300w/ch???
/RANT
Any suggestions for decent, reasonably priced amps?
The Behringer A500 is a good usable ca. 125 wpc amplfiier with profressional
and consumer inputs and outputs.
Don't confuse ratings with actual performance. If you haven't heard there is
a power war out there, and people will resort to all kinds of stupidity to
make it seem that their power amps have more power than the competitions.
This has reached its nadir with ratings systems such as PMPO, 1% THD, etc.
In fact juat about any good SS power amp will have less than 0.1% THD 20-20
KHz if you don't clip it. This may require shaving a few dB off of its
advertised power rating. Just about every power amp you see with X watts @ Y
wpc and 1 % THD will have 0.1% THD or less (usually far less and often down
below even 0.01%) at say 0.8 to 0.9 times Y wpc.
For example Behringer may on some days say that the A500 produces 500 wpc,
but after using one for a few years and testing it on the bench I think of
it as a 125 wpc (8 ohms) power amp. For another example, Behringer now
sells a power amp they call the EP4000 which internally seems identical to
one they called the EP2500.
This is not just about Behringer or just modern power amps. IME there was a
similar situation with the ca. 1980s QSC USA 850 and USA 900 just to bring
up a case that I actually have personal experience with. There were two
notable differences - the advertised power ratings and one was inverting and
the other was not. IOW they changed it from inverting to noninverting by
means of trivial changes to its input buffer circuitry. I think they
switched the wires going to pins 2 and 3 on the XLR jacks... ;-)
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