New Digital Switching Amplifiers

There are 2 kinds of noise:

One that goes out on the speaker leads at the switching frequency. We'll say in the 500 kHz range. (I believe Tripath and Nuforce may be closer to 1 Mhz.) The other is all the crud in the 60-100 Mhz region that will mess up TV reception ans some other things. Two different issues, 2 different solutions.

As for distortion changing with warm-up:

You can get the distortion to drop if you increase the "stand-by" current drain. Problem is, you run the risk of destroying the switching transistors if you get it too high. There could be a thermal change in that parameter in the unit under review.

So for a 10kHz signal to the speakers, the amp sends out 510 kHz?

No. There is no correlation to the switching frequency and input signal. If you took x number of any brand of "self-oscillating" amps, put them along side, they would all be different. The ones that I use will vary between 480 kHz to 510 kHz or so at idle.

The old style ones.......the ones that gave "digital" amps a bad name......used a fixed frequency oscillator. It remained constant.

does anyone happen to know, if the outlaw model 200, mono block is a digital switching amp, like what is being discussed here ?

What would it - high freq hash above 20k - sound like over speakers?

Bob Wood
http://www.GreatHomeTheater.com