Here is a very rare and interesting gramophone called the "Arbonphone".
A real collector's item, this gramophone uses a special "Phonos" device as the diaphragm and amplifier. This device is sometimes referred to as a "Diffuser" The needle attaches directly to the cone shaped clear plastic diaphragm and a spring arrangement adjusts the pressure onto the record surface.
When not in use, the diffuser stores in the lid and the turntable in the bottom of the case and is held there with a knurled bolt. To use the gramophone the turntable must be mounted onto the spindle and the diffuser into a post to the left.
. The quality of reproduction and volume is remarkable for this unique sound system. I have come across other devices somewhat like this, for example the "Lumiere" diaphragm used in a few HMV machines and also the "Do it yourself" card cone of the Guiniphone, but nothing with the effectiveness of the Phonos resonator.
I believe that Pathe produced as similar device and I have found reference to a somewhat similar gramophone made in Milan with a Phonos diffuser.
The gramophone is in very good condition and there can be very few of them left in circulation.