Are there any other AM/FM tabletop sets from the 1950's-60's besides RCA's
6-RF-9 which are transformer sets, not AC/DC ? Most everyone made AC/DC sets by the 50's.

The 6-RF-9 uses a 6V6GT audio output for big sound, but the radio has a 8 inch speaker, no tweeter for high frequencies. Regardless, it's among the best sounding table radio's of the late tube era. The KLH model Eight is a transformer set with push-pull audio, but it's only FM.

Others ?

I've had a couple Truetones (Western Auto) and Sparton AM/FM sets from the '50's that used a power transformer. I've got a '51 Silvertone AM/FM that uses a power transformer. I think power transformer style AM/FM sets were still fairly common, especially the better units, during the '50's.

My 60s Arvin tabletop AM/FM radio has a transformered supply, and rides on a set of 6AQ5s in a P-P configuration for big sound.

I believe it was more of a cost issue than anything and decient power output meant more B+ required. I restored an old Coronado AM/FM table radio that was transformered and with a SE 6V6 output. Really put out nice sound at a good volume into a 5x7 oval speaker.

I can only say I have a 6-RF-9 and it's a great radio. Mine is the mahogany veneer version which was unearthed from 3 layers of paint: avocado followed by burnt orange followed by what appeared to be chocolate mousse colored latex house paint. It's gorgeous now and a daily player in the kitchen. I did have to change the grill cloth and find a couple of knobs.

Sorry about the dust in the pic.

Many European radios from the 50s were transformered am/fm/sw sets. They sort of had to be, since they were designed to run on multiple different mains voltages. My Norelco has an EL84/EL86 sort of push-pull transformerless output stage, and my Schaub-Lorenz has an SE EL84 output stage. The Norelco I don't have a good 6x9 for, but when mated up with an output transformer to an 8 ohm speaker, it produces really spectacular sound.

That's for sure gadget. I have a big Philips Capella 643, about 2 feet wide with the piano type keys, 4 speakers including 2 electrostatic tweeters, 11 tubes, and a dial string that would make Mobius insane.