[geoff]

MarkK wrote:
Depends what you call signficant. If there was no reason for FETs to
generate distortion then equipment based on FETs would have
inherently low distortion. In actual practice, FET are competitive
with other active devices, some better some worse. For example, FET
based audio gear has never become the clearly dominant approach,
whether power amps or preamps. Ditto for audio op amps. More
traditional and non-traditional use of bipolar devices rule, which
is not to say that FETs have totally gone away.



Besides the distortion (which is easily improved per my previous
post) FETs as VCAs also suffer from the fact that it is difficult to
make multiple channels tack one another due to the wide variation of
gate characteristic from part to part.

This is not an issue in mono compressors but is an issue in almost
every other application.

And that gates on FETs are invariably high impedence. Of course not an
issue when used as switches, but the conducting section remains
semiconductor material.

geoff