With the current state of the art in loudspeakers, digital amplification does not make sense for anyone interested in sound quality as a first priority. Digital amplifiers can be made cheaper, lighter and more efficient than their analog counterparts, but digital amplification in and of itself does nothing to improve absolute sound quality above a good conventional analog amplifier.

Loudspeakers are purely analog devices and this will not change until some fundamentally different technology comes around that replaces the conventional speaker driver. This means the signal must be converted to analog somewhere before it reaches the loudspeaker. Where this takes place must be considered in light of where that conversion can be made with the greatest precision and least impact on sound quality.

The best DACs and digital processing ICs are manufactured for low level circuits. It is much better to process and convert signals from digital to analog (and vice versa) in a chassis where such things as the power supply and other circuitry can be better controlled and isolated. This is much harder to do in components like power amps where the high peak currents involved could disrupt the ability of the DACs to resolve the lowest signal levels (remember that a 24 bit digital word has a theoritical signal to noise ratio of 144db). This after all is the whole rationale of seperate audio components over receivers - that the low level signal processing circuits perform better in a chassis that is removed from the high current environment of a power amplifier section.

A digital amplifier violates good engineering practice by placing circuits which must process very low level signals in the same chassis with circuits which draw high currents in order to drive the loudspeaker.

Certainly digital amplifiers are going to become more and more common, but the entire justification for them is that they can be made cheaper, lighter, and more efficient than an analog amplifier. Notice that the better absolute sound quality is not mentioned anywhere in that statement. The simple fact is that an analog amplifer is the best method of driving an analog device like a loudspeaker when absolute sound quality is the goal rather than cheapness, weight or efficiency. If cost, weight and efficiency are the most important considerations (like in an amplifier made for automobiles or powered speakers for computer use), then a digital amplifier makes sense.

They do not make sense when sound quality is the major concern.

[This message has been edited by soundhound (edited February 14, 2004).]