Good point on the Class D. Whatever Henry Ho created with his H2O amplifiers he definitely designed them to work with 1 ohm Scintillas. Cannot speak to the exact design elements.
Control, was the wrong term regarding tubes on the ribbons. I can say that when I biamp my Apogee Duetta signatures I use my CJ Premier 11a on the high end and it is an unbelievable combination. I wish the Premier 11A sounded as good on my, Scintillas. The Scintillas have a more complex ribbon for the high end which includes additional ribbons for midrange. Maybe just not enough power at 70wpc. Still have not given up with this approach for, Scintillas. Obviously with biamping with passive crossovers everything has to be gain matched.
Control, was the wrong term regarding tubes on the ribbons. I can say that when I biamp my Apogee Duetta signatures I use my CJ Premier 11a on the high end and it is an unbelievable combination. I wish the Premier 11A sounded as good on my, Scintillas. The Scintillas have a more complex ribbon for the high end which includes additional ribbons for midrange. Maybe just not enough power at 70wpc. Still have not given up with this approach for, Scintillas. Obviously with biamping with passive crossovers everything has to be gain matched.