Just a little something to think about? (particularly Audioguru!).
I've just bought a Behringer PA mixer/amplifier, it's rated at 400W RMS per channel, and can be set to either stereo, dual mono (house and monitors), or mono bridged (800W RMS).
It's very small and light (two of the reasons I bought it), and uses a switchmode PSU. It also incorporates Behringers's "patented cool audio technology", which presumably means it's a class 'D' 'Digital' amplifier?.
Being the sort of person I am, I've stuck the scope on it to see what it does - for a start on the outputs there's 440mV 500KHz sinewave, confirming it's a class 'D' switching amplifier.
Now being a 'digital' amplifer it's EXTREMELY important that you don't clip the outputs (just as it's vital when recording a CD), so as such it limits before clipping!.
Now this wouldn't be a problem?, EXCEPT an anlogue amplifier doesn't usually limit like this - and a 400W RMS amplifier will happily provide 800W peak (hence the absurd claims of home and in-car amplifiers). The class 'D' amplifier can't do this, so the 400W amplifier can only supply 400W peak.
This means that an analogue amplifier will sound considerably louder than a similar specified digital one - or even a considerably higher specified digital one.
I consider this means you can't compare the ratings of analogue and digital amplifiers?, and I'll be interested to see how loud it is in practice when I have to do the PA for my daughters band at their next gig.
I've just bought a Behringer PA mixer/amplifier, it's rated at 400W RMS per channel, and can be set to either stereo, dual mono (house and monitors), or mono bridged (800W RMS).
It's very small and light (two of the reasons I bought it), and uses a switchmode PSU. It also incorporates Behringers's "patented cool audio technology", which presumably means it's a class 'D' 'Digital' amplifier?.
Being the sort of person I am, I've stuck the scope on it to see what it does - for a start on the outputs there's 440mV 500KHz sinewave, confirming it's a class 'D' switching amplifier.
Now being a 'digital' amplifer it's EXTREMELY important that you don't clip the outputs (just as it's vital when recording a CD), so as such it limits before clipping!.
Now this wouldn't be a problem?, EXCEPT an anlogue amplifier doesn't usually limit like this - and a 400W RMS amplifier will happily provide 800W peak (hence the absurd claims of home and in-car amplifiers). The class 'D' amplifier can't do this, so the 400W amplifier can only supply 400W peak.
This means that an analogue amplifier will sound considerably louder than a similar specified digital one - or even a considerably higher specified digital one.
I consider this means you can't compare the ratings of analogue and digital amplifiers?, and I'll be interested to see how loud it is in practice when I have to do the PA for my daughters band at their next gig.