Couple of em use Philips modules, again Philips invents it, others use it. Same modules used probably in so many things, HTIB, etc. High end? Take an amp module put it in a fancy box, charge too much. CI Audio uses it so did one other.
But the Sonic Impact amp, like all amplifiers using the Tripath chip, is not class D. It is spec'd as class T and done so to make the point of diversion between the two operational modes. I see no indication in WP's review that he found the class T amplifier sensitive to cables nor possessing any particular problems in the highs. Both classes are apparently sensitive to load impedance due mostly to the series type output filters used to reduce ultrasonic noise. This sensitivity may alter the frequency response slightly and, when paired with the wrong speakers, offer less than high end sound quality. This is where the air cored inductors make a large difference in the sound quality of the slightly more expensive T amp competitors. At any rate, the rather high output impedance of the T amp should present no problems to anyone used to running tube amps. This should be a problem only to the extent it will require some degree of knowledge to achieve system matching. The class T amplifiers might not be a great choice when paired with existing speakers, should those speakers present less than optimum loads for the amplifier. (In other words, don't just plug these amps into an existing system and hope for the best.) This sort of matching doesn't seem all that unusual in the world of high end audio. It does seem to indicate that amplifier designers and speaker designers never congregate in the same room. I'm still trying to figure out why anyone would design a speaker that dips down to 1.5 Ohms. It just seems cruel.
We'd really like Stereophile's staff to go on the "cheap amp" line by reviewing one of our amplifiers...
In general, Stereophile doesn't review modifications. Also, for a company's products to be consiered for formal review, it needs to have at least 5 dealers (if distributed conventionally) or, if only sells directly, needs to persuade me that it is an established business, run on professional lines, with a commitment to customer service.
JOHN, PLEASE before reviewing this stuff you gotta do some AVA It's meets ALL your criteria just mentioned!!! and BEYOND, would you say almost 40 YEARS in business is a well run STABIL operation, committed to "customer service"? Come on, we know it is...Ultra series, Pre, DAC,phase inverters, do some OmegaStar EX rebuilds in the HAFLER P500/DH500/XL600chassis...It's all good, all reliable, all priced for mortals, and based on reality engineering. PLEASE do some www.avahifi.com Get in touch with Frank VanAlstine PLEASE
JA, it matters not to me whether you review the AudioDigit amplifiers. I know your review schedule is packed with companies wishing Stereophile's stamp of approval. I will, however, for what it's worth, offer my opinion concerning AudioDigit's quality, professional commitment and concern for customer satisfaction. I own their small (kit) Tripath based amplifier and find it a worthwhile step up from the Sonic Impact, which I also own. These two class T amps, along with a few Tripath chip based "T-amp" competitors, remind us that audio should, as WP stated, be fun and not fussy. Perhaps a follow up with the SI, the AudioDigit and one or two of the other class T competitors might be in order.