I found this about Single Ended Push pull amplifiers in a Philips publication, not had chance to study it properly but looks an interesting read.
Is about page 42 in a 360 page document, about 10 pages in length, there are lots of other topics in the document.
Philips used the EL86 arrangement shown in fig. 3 with their own high impedance loudspeakers.
Yes Philips seemed to like this arrangement. I had the pleasure of restoring one of their 'Bi-Ampli' radio's some years ago...the first time I had actually seen one in the flesh so to speak. The one I did had an EL84 and EL86, the EL86 being the 'top' valve and designed for this circuit having a high heater/cathode insulation since the cathode was at roughly half HT. There have been numerous variations and one I've seen is a record player using an EL84 and a UL84, the UL84 being the 'top' valve again because of the high heater/cathode insulation required. Another variation used PL81's.....! Seemed to be much more popular with their continental designs.
The thing is, they all sounded superb.
Philips designed some interesting circuits that went against what was considered standard practice but usually worked extremely well.
Our German-built Philips radio had a strange arrangement of a forward facing woofer and upward facing tweeter fed by a separate transformer. I only know that because a circuit-diagram was sellotaped to the inside of the rear cover.