The PCB-board:
The PCB-board has two functions. The normal function which is that it contains some electronic circuitry and PCB mounted buttons, but it also functions as part of the construction that keeps the Electrumpet together.
The PCB-board is fixed under the top parts of the normal valves of the trumpet. The metallic frame is then clicked on the PCB-board fixated by both the top parts of the valve (around but not under it) and the switch buttons on the PCB-board.
On the board there are 8 sockets for the analog controllers with two to three holes for every controller. Of the 8 sockets there are 7 in us. All the analog controllers are not attached directly to the PCB-board, but they have wiring with plugs attached to them that fit in the sockets.
The circuitry on the PCB board is simple. Only resistors are used as modifying electronic components next to the sensors and switches. Either as a pull down resistor for the switches, or as a series resistor in combination with the pressure sensors and the ribbon controller. You can find the layout on the PCB board here.
