Originally Posted by dmsdms
I just ordered one of these and hadn't seen the 60W/ch at 20Hz-20Khz number (they don't post it on the Wyred4Sound website). That's a real bummer. I just ordered two pairs of relatively inefficient surrounds (84db@1W) and 150W/ch computes to well within my volume needs but 60W/ch is cutting it a bit close. I figured that class D amps are generally multi-mono designs and so number of channels driven had little effect on power output. I'm wondering if I should cancel my order and go with the Mini MC 7 Channel instead.
I wouldn't worry about it unless you plan to use the amp to drive subwoofers. "All channels driven" is probably an unrealistic spec, and it's a reasonable design compromise to use a common power supply that can burst power into channels that need it, while not being able to drive them all continuously at that level. Music comes in bursts, after all, not continuous sine waves. And it doesn't come in continuous sine waves from seven directions at once!
That said, the W4S amp is B&O's AVR amp module in a nice case, and their spec sheet is going to trick people who don't read between the lines. (As a general rule, if a power amp isn't explicitly given an "all channels driven," its power-supply is not designed to provide the claimed power into every channel at the same time for very long.)
Still, Icepower's newer modules are very good. I briefly had an amp with the smallest one, and it sounded just like a good solid state amp of that power level. Does the Mini MC7 use the newest (ASX2) amp modules? If not, the MC 7150 is honestly probably the better amp. Earlier Icepower modules suffered from "tube sound" syndrome, because their output impedance was high. The new ones correct for it, similar to the Hypex amps that are IMO the gold standard for Class D up to now. The newer ones also seem to hiss than the old ones, though I've not used a W4S amp with the older modules and I base my comment on experience with a couple Rotel models.
Also, every marketer claims to "tweak" something. Doesn't make it true, of course. Chances are the "tweaks" are really just B&O's recommended input buffer circuit.Edited by DS-21 - 4/2/13 at 10:11pm