The Hifi Trajectory Of Class D Amplifiers

Although technology is much different, I think it a good analogy that Class D eventually will do to other amp designs what digital cameras did to film cameras. it may take another 5-10 years of market growth still to totally dominate in most common applications. The reason will be because the technology is "greener" as well as being capable of doing the same applications as older amp technologies better and for less in general.

Tube amps have enough unique properties though I think to stick around even longer as a niche technology, much like phonograph technology.

Obviously you guys haven't heard the SPEC Real Sound amp. Best, Rob

11-19-15: Mitch4t

George, is this because hifi mfgs pockets aren't deep enough to finance the research to advance the technology?

It's up to the massive component manufacturers, that HiFI manufacturers purchase their components off to advance this technology.

As for guys like Nelson Pass and such, they will also in the future use Class D when this technology is reached.

Others manufacturers who have already invested in Class D, are getting into it because it's already a financial viable product to make
As the components that are around now will make an amp that costs half the price of linear amps to manufacture, even though the technology is not yet matured enough.

Cheers George

Yes, the semiconductor industry really doesn't want to make linear devices if they can help it. Switch mode devices are easier and more profitable.

Kijanki, in case you didn't know it, most decent bass guitar amps are built along hifi lines. They have to be in order to sound right. If you get a chance, look up a schematic of an amp called the Marshall Major and you will see what I am talking about.

Atmasphere, Bass amps were and often are made as cheap, crude implementation of class D, where you can get a lot of power in inexpensive portable package. Because of that many think of class D only as a crude inexpensive way to get lots of power. I'm not sure why you even brought the case of 500W class D not being able to keep up with 400W tube amp, since it is irrelevant to our discussion and refers to particular design and the way power was specified (only 6.7% difference in perceived loudness between 400W and 500W). In addition, in last decades bass amplification in larger venues got into PA system, making raw power of the bass amp relevant only for small theaters. Class D can be designed with any headroom, often has line and load regulated power supply, that doesn't sag under big loads and soft clipping similar to tube amps (whole Icepower family). In contrast, class A SS amps have very limited headroom, mostly unregulated power supply and hard clipping, but they are great example why suitability of given amp class for bass head says absolutely nothing about sound quality in home stereo system.