Thanks for the links Voodoochile! The Spectron site in particular has a good desription of the basic theory underlying their design. In short, the input signal is converted to the digital domain, then amplified; hence the moniker digital amplifier. Both digital and analog input signals are converted to PWM (Pulse Width Modulation) format and then modulate a carrier. The resulting signal is then amplified to output levels, and filtered to remove the carrier. Note that the output signal is in fact a square wave.
There are of course merits to this design because class D amplifiers are efficiency champs. Die hard 'analog' audiophiles may have issues with so much DSP (Digital Siganl Processing), however DSP chips have advanced strides in the last few decades. Indeed, audiophiles routinely talk about 'analog' sounding CD players which actually benefit from advanced DAC and DSP chips. Personally, I love my 'analog' sounding CD player and would love to hear these new digital amps. It would be interesting to hear from anyone who has compared the sound of the analog vs digital inputs on the Spectron.
There are of course merits to this design because class D amplifiers are efficiency champs. Die hard 'analog' audiophiles may have issues with so much DSP (Digital Siganl Processing), however DSP chips have advanced strides in the last few decades. Indeed, audiophiles routinely talk about 'analog' sounding CD players which actually benefit from advanced DAC and DSP chips. Personally, I love my 'analog' sounding CD player and would love to hear these new digital amps. It would be interesting to hear from anyone who has compared the sound of the analog vs digital inputs on the Spectron.