Originally Posted by
Mandryka
I own a Krell KSA 50, it's being restored right now, I haven't heard it. I wonder how it will sound compared with the Electrocompaniet.
Why did Krell (and others) make such powerful Class A amps if 10W is so loud? Was it just for driving inefficient speakers in big rooms? I mean there's a KSA 200!
And no-one ever says that 10W Class B is loud, that you'll never clip a 10W amp unless you're in a large room! I don't understand what's going on actually.
Jez posted this on another site, basically Krell fib about the power output of their amps, but in the opposite way to most manufacturers. The KSA 50 is actually a 75W amp, but will do 50w Class A as has been proven by independent measurement.
It’s a bit misleading all this Class A malarkey these days TBH, in the strict sense a true or “pure” Class A amp only has one pair of output transistors per channel, which limits output power available. Most “Class A” amps these days have more than one pair of output transistors- these are paralleled up to give more power, so in the strict sense of the definition are not Class A, but highly biased Class AB. In other words they will give a few watts in A before crossing into AB.
It’s pretty easy to tell how much an amp will do in A, just take a look at the heat sinks and how hot they get. Once you’ve experience of a few Class A amps, it’s pretty easy to estimate the power in A that will be available, just think of the size of the heat sinks on your Krell- 50w in A dissipates A LOT of heat.
“Music has always been a matter of energy to me, a question of fuel. Sentimental people call it inspiration, but what they really mean is fuel. I have always needed fuel. I am a serious consumer. On some nights I still believe that a car with the gas needle on empty can run about fifty more miles if you have the right music very loud on the radio”
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