Class-D sound - any comments?

[alvinlim]

Here's a pretty inflammatory statement from a respected loudspeaker designer - any comments will be welcomed!

http://www.bryston.ca/newsletters/91.../vol9_iss1.pdf

[cowanrg]

i can only assume there have been significant improvements since april of '05, when that was written...

[BWRX]

"A good engineer should always recognize when a design direction or technology path is wrong."

So does that mean he's not a very good engineer then?

[cowanrg]

apparently so...

if you read in the first paragraph, it said he was with sony. this was about the time sony started doing digital amps in its ES line of receivers. and shortly thereafter, the digital amp market really took off.

sounds like its "just some guy" that was in the anti-class D camp. everyone misses the boat.

[Workhorse]

I think that Engineers who are unable to build an excellent sounding Class-D amplifiers, thereby tend to make these type of negative statements...which clearly shows there INCAPABILITY TOWARDS INNOVATIVE EXCELLENCE....

K a n w a r

[Pierre]

After having built my own Class-D designs during nearly 3 years and having also tested some commercial Class-D modules, all I can say is that I won't return to class A or AB.
I agree that this technology is challenging, but who said it was going to be easy?
There is always people that show their own limitations by discouraging others to try what they are unable to do.

[classd4sure]

His understanding is made obvious by almost every single, selectively polar, remark he made regarding the technology as a whole.

"We fear that which we do not understand". He doesn't.

Please, let's not ignore the other aspect here, Bryston's motivation to reprint that. Can you smell the fear? Be very afraid!

I think the only real questions here are how long it will take them to come up with their own twist of a class d amp that's been patented many years ago, or if they'll simply concede and use someone else's modules, or, go out of business.

As far as Dan, you have to find some humor in that it sounds like he's trying real hard to come up with a bad "sub use only" class d amp....that's far too ironic to fully appreciate.

[koolkid731]

An audiophile friend of mine said to me one day that "Audio engineers" are typically a "lower grade" of EE. I didn't quite believe in his statement, because it's not that easy to compensate for cross-over distortion. Dr. Bruce Candy did revolutionize linear amps with his ultralow distortion Halcro amps. He also applied for a cryptic patent on his class-D amps, which use gigahertz transistors to minimize distortion. I personally don't understand how his delay circuit works to do that. He did inspire me to look into design of distortion-free power amps. However the law of diminishing return and niche market prevented their commercialization. High price => low volume. I wonder about Halcro's sales volume.

In most disciplines, there will always be something better that comes along. To say progress can be stopped, as Dan did, is foolish. He didn't seem to see the obvious problem of heat generation of Bryston amps. Bah, humbug!

[classd4sure]

Hi Koolkid,

I've seen Bruce Candy's patent on class D amps. I actually found it to be one of the least cryptic patents. What delay circuit do you speak of, have you a reference handy?

For what his amps seem to be sold for I dont' imagine he needs to sell very many.

Cheers,
Chris

[phase_accurate]

I think the only real questions here are how long it will take them to come up with their own twist of a class d amp that's been patented many years ago, or if they'll simply concede and use someone else's modules, or, go out of business.

There will always be demand for conventional amps like Bryston et al. But their sales figures will fall.
The best way to "strike back" would indeed be investing into the development of own class-d amps instead of bashing it.
Although I already see the opening of the advertisment for their fist class-d amp generation: "For decades engineers were striving to build high-quality class-d amps. But this was impossible until recently when we developed our revolutionary xyz amp technology ......... "

Rergards

Charles