Typically using MOSFETs as the gain devices, (often as current sources rather than voltage sources), most of his designs operate in Class A, with all the low distortion of small signal benefits generally associated with that. He is also known for his advocacy of "minimalist" designs, which reduce the circuit complexity and number of components through which the audio signal must travel, resulting in any residual distortion having a very simple distortion spectrum. His more powerful designs that go beyond what can practically be realized in Class A (such as the Threshold and Pass Labs products) operate in Class AB1 but retain a heavy bias so that they operate in Class A during quieter passages, and great emphasis has been given to avoiding or minimizing switching effects.
I had not seen his wiki page - thanks for that. The following caught my eye:
I always thought his Pass Labs designs are not pure class A all the way and this confirms that.
I had not seen his wiki page - thanks for that. The following caught my eye:
I always thought his Pass Labs designs are not pure class A all the way and this confirms that.
His class A designs deliver the full rated power in class A. Look at Northstar's post.
For several years Pass Labs has specified the nominal wattages at which our amplifiers leave push-pull Class A operation into an eight ohm load.
His class A designs deliver the full rated power in class A. Look at Northstar's post.
You must not have read it yourself:
take a closer look; they make power claims at the point where is switches to AB, therefore, their designs can put out more power, just not in pure class A. It's like saying my car to do 0-60 feet in 1 second, and God knows this means for 0-60mph. Still, their Class A rated power is quite comfortably high.
Right. It's a language thing. For instance, the full rated output for the XA100.5 is 100 watts at class A. Of course it puts more out in class B, but the rated power I refer to is the class A, as that is what it is advertised at, 100 watts. I think of the class B as a bonus power rating.
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