The switching time is an issue. The output devices have to switch on and off at a pretty high speed. The problem is, they can't both be conducting at the same time. That is to say, it takes a certain amount of time for the devices to turn on and to turn off. If one is not quite off while the other is turning on, you get something called 'shoot though current' as the devices are essentially a short across the power supply without doing anything to drive the speaker. Shoot through current causes the output devices to heat up quite a lot. So it has to be avoided!
To solve this, there is something called 'dead time'. Its a circuit that makes the output devices wait just a little so that one is completely off before the other starts conducting.
The longer the dead time the higher the distortion. So if you can switch faster dead time is reduced and so is distortion. Right now the technology is to the point where the amps have become practical for mid fi, but they still have a ways to go before they can challenge a good class A transistor amp or a good tube amp. There is no question that this is a technology to be watched.
To solve this, there is something called 'dead time'. Its a circuit that makes the output devices wait just a little so that one is completely off before the other starts conducting.
The longer the dead time the higher the distortion. So if you can switch faster dead time is reduced and so is distortion. Right now the technology is to the point where the amps have become practical for mid fi, but they still have a ways to go before they can challenge a good class A transistor amp or a good tube amp. There is no question that this is a technology to be watched.