"Rusty Boudreaux" wrote in message


"Robert Morein" wrote in message
...

MOSFET amps are the most durable of all solid state amplifiers. They
can drive any load without output damage, and if you're reasonably
lucky, they will survive a dead short. The MOSFET transistor is now
ubiquitous in power switching applications because of it's
ruggedness.

Really? That's an exceptional claim. Why do you claim MOSFETs
amps are any more durable than a bipolar output stage amp?

It is true that MOSFET devices sometimes have greater inherent durability,
while BJT devices MUST be used with carefully-engineered protection
circuitry.

Bipoloar transistors do exhibit secondary breakdown and current
hogging/thermal runaway. However, in a competent design both
issues can be firmly addressed. Reliability and durability
should be no worse than a MOSFET amp.

Agreed. Morein doesn't seem to understand the kind of tough use and abuse
that well-engineered BJT amps routinely tolerate and even thrive on, with
appropriate circuit design. It took a while for engineers to figure out how
to protect BJT output stages from use and abuse, but that was all over
decades ago.

The reason MOSFET output stages are ubiquitous these days is cost
and availability.

Actually, it's BJT output stages that are ubiquitous but you've got the
reasons right - cost and availability.