Getting a turntable to spin at 78 is easy, the real issue is the groove size is WAY wider than an LP and one ends up with a ton of noise from the stylus riding at the bottom of the groove. I'd recommend an separate TT with a proper cartridge to play 78's, not simple, but it is what it is.
78 RPM turntable
I just recently bought a truck load of old 78s from an estate sale. I haven't had the time to even go through them yet. The ones I have are in mint condition. I mean thick records that you could hit someone over their head and not even break them. My problem is finding a turntable that will play these 78s as well as 33s. Anybody have any suggestions?