In Reply to: Tripath amps have no crossover distortion ? feedback ? posted by tjnailit on November 7, 2012 at 17:24:17:
I believe they are referring to the amplifier classes of operation. In a class AB, the normal mode. one output device handles one half of the waveform and the other device the other half, (very simplified explanation).
In a digital amp the waveform generated, is simply composed of "spikes" for the lack of a better word, which at the amplifier sampling rate creates a toneburst up or down, depending on whether or not it is negative or positive. These bursts are then smoothed over by an inductor and capacitor in most cases i have seen.
In normal transistorized amps, the crossover from one device to another is supposed to create a slight distortion. In a pure class A design, the output device handles both halves of the waveform, never turning off. In class B design the cut off point is the zero point. In AB designs, the cutoff point extends a bit past the zero point so there is no harshness from a transistor turning off and on. The signal carrying transistor carries the signal into the other half of the waveform where the other device has presumably already turned on. This is used because the transistor does not develop too much heat from being constantly .
While digital amps exhibit no distortion due to signal crossover, they are still dependent on the digitized signal spikes being smoothed over by the following devices ( inductor and cap), and of course the quality of those components has a significant effect on the sound.
Hope this helps a bit, probably more confusing, though. Google amplifier classes of operation for more.
Stu
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- RE: Tripath amps have no crossover distortion ? feedback ? - unclestu 21:46:34 11/07/12 (0)