Paralleled Transistors

Very interesting and informative posts .....thank you to all. I recently auditioned a Danish Gato amplifier which uses one pair of large N Channel Mosfets per channel.(200/400/700 wpc) The sound was very pleasing, with a natural tonality, similar to a class A Gryphon type sound. Curious!

Short answer: no. Everyone parallels devices. Also paralleling them is not really related to complementary pairs (NPN and PNP) which are used to achieve DC coupling to speakers. Which almost everyone does.
Exceptions: tubes and some really oddball, very low power FET amps.
I’d argue that if you want to go to the trouble and cost to parallel up a gazillion devices, you could get some theoretical benefits. Nelson Pass certainly thinks so.
G
Ps: after posting this i saw that Nelson's name was being bantered about above, but for the opposite reasons i was. Nelson once designed, or tried to, a power amp using hundreds of tiny N-channel JFET TO-92 devices that he really liked.
pps: In sane-land, i recently completed  a design for a headphone amplifier with no loop/global feedback. This adds to the output impedance issue noted above, but is inherently stable into any load (including some crazy impedance 'phones). Among other things, it parallels quite a few to-92 NPN and PNP devices to achieve power handling temperature margin, and linearity. And it just rocks.

There was an extensive discussion on Audiogon about a year ago, when the late great Roger Modjeski hosted a thread entitled something like, "Ask an amplifier designer a question."

We discussed paralleling and matching transistors at some length.

Further to your question, I like epitaxial output transistors from Sanken (beware of counterfeits). Their higher power transistors tend to be slower, which you can absolutely hear as imprecise. Hence, if you want to hear the best your topology can do, you have to parallel.

Parallel transistors, Moffett or tubes is always not a good idea. It is just a compromise - to deliver more power.

I'd just like to reiterate, you might get some really interesting discussion on the pass labs section of diyaudio.  As you can tell above, Nelson's designs are cited both as evidence in support of paralleling devices, and for simplifying and getting down to minimal parts.  Because of that, the crowd over there is actually supportive of both approaches and might give you some additional thoughts once the thread here runs its course.