Quote Originally Posted by mamzh
I am looking for MF integrated amp. The local dealer told me a new integrated MF A3.5 will come out on this June with price $1600. It has 125 Watts to 8 ohms and 200 watts to 4 ohms, 70amp peak current, all the other spec is as same as A5. It has the circuit used in A5. At $1600, I can find the used A308 with 150 watts to 8 ohms and 300 watts to 4 ohms, but less peak current 40amp. My question is, for watts and peak current, which one is more important. I want to use it to drive Magnepan MG1.6 in the future. Thanks!
I love the Ohms Law: V=I*R and the Power Formula W=V*I
You can substitude the V in the Power Formula and get: W=(I*R)*I
Then take out the I (current-amperes) = SquareRoot (W/R)

So if the amp puts out 300 W into 4 Ohms, Then the Current will be I = SquareRoot(300/4)=8.66 Amperes.
Let's assume the impedance of the speaker drops to 1 Ohm!!!! And this same amplifier tries to put out 1200W even briefly, assuming it has a beefy power supply... Then the current passing through its output stage will be I = SquareRoot(1200/1) = 34.64 Amperes

So as you see not even in your wildest dreams the the peak output current shouldn't exceed 40 Amperes. I sincerely don't think the 70 Amperes specification will help you much (especially from a lower powered unit).

Do keep in mind that I had a hard work today. In my country it's night now, and I had a couple of glasses of gin&tonic by now. I hope I haven't miscalculated anything.