The Hifi Trajectory Of Class D Amplifiers

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.

My Class D amps at home are top notch.

At the gym, they use inexpensive pro Crown Class D amps with large horn loaded speakers and instructors use their Apple devices as source. Not audiophile material in there with lots of echo and speakers in corners near ceiling but gets the job done nicely.

Very versatile technology!

In terms of sound good Class D amps I have heard and good tube amp setups I have heard differ not just in components used end to end but soundwise as well. Tube amps often provide some degree of warmth through the midrange. Class D amps I have heard deliver more of a "liquid" midrange but not warm at all. You have to add that somewhere else if warmth is what you seek. A good matching tube pre-amp does nicely.

I have one mostly digital (with phono and line level analog inputs plus various digital) integrated amp (Bel Canto C5i) and my main rig with BC CLass D amps and ARC tube pre-amp. They are both excellent performers but have their sonic differences, mainly the touch of warmth the ARC preamp delivers. I can listen to either happily for hours.