2.4 Topre

Topre are the switches that can generate heated debates precisely because they are hard to include in a category. These are electrostatic capacitive switches and also employ the rubber dome technology – specifically dome over membrane. The difference when compared to a regular membrane keyboard could not be bigger, however, even though Topre is jokingly called “posh membrane”.

In a regular membrane keyboard the keycap pushes directly onto a rubber dome which closes a circuit by making contact with its carbon or metallic part to the metal circuits on a plastic sheet when pushed down to the bottom.

Anatomia unui switch Topre

Topre switches however are capacitive and non-contact which means that the actuation process to yield a letter on the screen is much more complex than what happens in a regular membrane keyboard. There is no plastic sheet with metallic contacts instead there is a complex PCB which measures the capacitance of the switch when pressed down. The switch assembly itself is more complex and does not consist of only a plastic actuator + rubber dome + plastic sheet – instead there is a keycap mounted on a slider which glides through a housing pressing down on a tactile rubber dome on top of a spring on top of the capacitive sensor. The bottom out is satisfying when it happens (but is not necessary for actuation) and so is the acoustic signature of the keyboard as a whole. This is what the Topre enthusiasts call “the real thock”.

The quality of the typing experience, of the overall finish, and the materials involved in making PFU keyboards (the Realforce and HHKB series) invariably places them in the high end category.

Topre is an interesting switch. Thinking about the motto at the beginning of this write-up we can derive some more wisdom. When you are riding a horse with the same saddle for a long time the saddle also adapts to the rider. It is not just the rider adapting to the saddle. It is rather similar to the situation where you are buying a new pair of leather shoes that feel quite tight only for them to turn in the most comfortable shoes you have ever worn in a relatively short amount of time.

Topre switches change over time. Almost all Realforce and HHKB users describe a process through which the sound signature becomes lower in frequency over weeks and months and becomes more and more “thocky”. This is probably related to a break-in process of the switches’ assemblies.

HHKB Professional Hybrid Type-S. Topre switches factory silenced, PBT keycaps, Bluetooth or USB type C, limited factory programmability.