Ex3ma, and pure Class A

摘要

I enjoyed Ken Kessler's article on the Sonus faber Ex3ma [see HFN Jul '14]. But the pictures of the crossover with the inductors and Mundorf capacitors reminded me that the company didn't continue one of the unique features of the original Extrema -the capacitorless crossover. Here, instead of a series capacitor as the high pass element for the tweeter as is conventional, the high pass was accomplished with a parallel inductor yielding a lst-order crossover without a capacitor (the best capacitor is no capacitor?) - a quite unique situation. It would have been good to see a second iteration of this concept. But I suspect Sonus faber achieved superior results this time around with a more conventional approach using the superior capacitors available today over two decades later.