Anyone who has worked in pro audio knows that the best mic pre's are pure class A. With class D amps being so favorable here I was wondering if anyone has tried to make a class D mic preamp?
It's possible, but why would you want to? The advantage of class D is efficiency, mic pre's are very low power devices where efficiency is of little concern. Class A is much more appropriate for pre's of all kinds
Efficiency is a concern if youre mic pre must be battery powered - not phantom powered. Besides the 14 mA phantom power can source is not a lot for Class A circuits.
You won't save much power with class D, you need at least a high speed comparator for class D, and those are fairly power hungry.
I personally wouldn't put more than a unity gain buffer (likely a small JFET source folllower) in a phantom powered mic pre.
What features are you planning to put in?
I personally wouldn't put more than a unity gain buffer (likely a small JFET source folllower) in a phantom powered mic pre.
What features are you planning to put in?
Some CMOS logic chip may serves as low power high speed comparator/output stage.
But a class D preamp may disturb the following circuits -- it has high frequency output ripples.
But a class D preamp may disturb the following circuits -- it has high frequency output ripples.
What are the approximate input level, typ. and max, and the required output signal?
I agree that a HC gate can work as a good high speed comparator, providing the power rails are clean.
I agree that a HC gate can work as a good high speed comparator, providing the power rails are clean.
I don't see the motivation behind such a device, apart from being an interesting topic for experimentation.
Regards
Charles
Regards
Charles
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