IRFP450 for output stage

[muddasirwaheedmalik]

Hi,
can IRFP450 good for Class A amplification, its transfer curve seems very parallel and linear, any design for it ? regards

[MarianB]

Any MOSFET output amplifier should work as long as you keep in mind it's limits.

[muddasirwaheedmalik]

I mean SQ, sound Quality

[MarianB]

Well then, if you think about the fact that many people say that vertical mosfets are more of an industrial devices than audio ones than you might think there is no Hi-fi audio power amplifier for them, but that i think is more of a subjectively opinion.

[CBS240]

Many people say they are not for use in Hi-Fi, I disagree. It is all in how they are used. I believe they are exactly the type of device to use when driving a highly reactive load such as a speaker, motor, transformer, inductor, ect. However, if one uses them as if they are a BJT, then I believe they will be dis-pleased with the result. Of course they are not BJTs and work on an entirely different principle. These devices are intended to be used for switching purposes, so some special effort must be taken to use them as analog amplifiers. They are simpler to use for quality class A operation due to the Gm characteristics, Mr. Pass has several examples, search the Pass forum. Class AB is a different story.

You should choose a device based on the transconductance you require.