FYI, I've found a datasheet
http://www.runlite.cn/userfiles/js9jaw90nxmvc1372646905.pdfOn this guys blog:
http://electronupdate.blogspot.caA base of an E14 fitting is like 14mm x 15 mm (from memory) so you really dont have much space for electronics. What I expect to be happening, is rectifying mains, smoothing capacitor, and constant current linear drive. The two filaments are in series, so it would turn on at 140V.
I dont want to mess with the bulbs and fittings, what I have in mind is to convert my lamp to output DC or at least somewhat smoothed DC. I hope the rectifier inside are properly rated for this. If Mike is right and they have a capacitor on the mains directly, then I'm in trouble, and I'm actually not sure what to do with thees other than break them for the filaLED (made up word, seems apropriate).
Quick comparison of light output waveform fluorescent (inductive ballast) vs. LED filament
Those scope screens are worth a thousand word.