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Besides the aforementioned circuit breaker, the back panel sports a 12V DC trigger input and slider-switch selectable RCA and XLR inputs. Otherwise noteworthy is the proper location of the power IEC well away from signal sockets to make proper cable routing as easy as it should be.


On to business. As the next photo shows, the B&O board is peopled with a number of non-stock capacitors. "Our input stage improves signal coupling between your preamp and the ICEpower modules. That's for two reasons. One, the standard ICEpower module presents 8K on the hot and 10K on the ground leg. Driving 8,000 ohms is a lot less efficient for a preamp than 61,900. Tube preamps love our amps. Two, our dual-Fet input buffer is direct-coupled and fully balanced. This means the dual-differential ICEpower boards are driven balanced, not single-ended. That makes for a lot better performance. But there's more. The voltage-to-current conversion of the Fets creates a smoothing and sweetening action which perfectly complements the starker brighter voicing of the B&O boards. That's quite similar to a tube driver stage - except that ours is DC coupled and doesn't suffer the maintenance issues of tubes. Parts quality for our input buffer is high, including copper-lead Dale Rn55D resistors, Wima and Muse filter caps and thick PCB traces. The original circuit was designed by Bascom King. As time passed, we made some changes by adding a silent and beefy power supply. Also, the individual Toshiba Fets we now use are optimized to be pair-matched for optimum DC trim levels. On the ICEpower boards themselves, we bypass certain input coupling caps while maintaining the important DC protection. We also enhance the feedback servo for better bass and use a mix of high-purity copper and silver 14-gauge hookup to wire up the outputs. The thermally activated push-to-reset circuit breaker allows 10 times the rated current during peaks over a conventional power fuse."


Clearly not all ICEpower amps are made the same. We'll safely assume that different implementations and auxiliary circuits also sound different and distinct. With Wyred4Sound's, you obviously don't drive stock. Now add the usual (high power, coolly efficient operation) and the not always as usual (extremely solid but non-bling construction and a very fair price) and their ST-500 stereo amp is no joke. Or as the late John Potis and former 6moons scribe put it on Positive Feedback Online (while on our staff, he'd awarded Bel Canto's ICEpower Ref 1000 monos our first-ever Lunar Eclipse award for electronics and felt the ST-500 to be very similar), "...it comes too damned close to the best out there at a price way too reasonable to be ignored."

With three FirstWatt amps in the crib (F5, J2 and M2) plus ModWright's newest KWA-100 and Burson Audio's fully discrete PP-160, how would the Californian analog switching amp hold up? After all, popular—snobbish—audiophile perception still insists that class D can't compete against credible traditional amps. While plenty of actual listeners have begged to differ for years, this bit of class-mongering racism prevails. Even serious reviewers partake. I also had one very well-known manufacturer take Frederic Beudot to task who compared an expensive Hypex-based reference amp with very butch power supply to the protester's class A loaner. With his Zu Essence speakers, Frederic found his own class D amp as good and in certain aspects a superior match for his system. The manufacture rmeanwhile argued that "we and our dealers all know that class D can't possibly compete with class A". Really? This man clearly felt insulted. At the very least, my particular assortment of amps could shed some light on how such judgment works out in the realms of $1.500 - $4.000 contestants keeping in mind that EJ Sarmento's would be the cheapest by half or more.
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