So I guess I am just an old Dinosaur who will stick with the beautiful vintage units from the late 60's, 70's and early 80's. I love collecting, repairing and restoring these older vintage units that use typical BJT devices I just closed down my beach club for the season, and had to remove my "Sound System" from the Cabana I use a recently restored Quad Pioneer (QX-747) so that I can easily set different volume levels for the pair of inside cabana speakers, vs the pair of Pioneer CS33a's that I use outside the cabana. Attaching a picture of the Pioneer Receiver, and notice the Akai GX head 8 Track unit on top that is a daily driver. I used to install/service/support Business Sound systems, but that was a long time ago in the disco days, where sound was a lot more contained that at a modern "Concert". 2 or 4 big speakers like original EV Eliminators, being driven by a couple of Akai or Phase Linear Amps usually covered the place very nicely. Maybe if I was still active in the sound system business as I was in the 70's I would be using big Mosfet amps. But seeing that I am retired from my career running Big Bank Data Centers, and being 67 years old, I should stick to my enjoyable work with vintage gear. And besides, I probably couldn't move those heavy Mosfet amps around anyway.