My Br3Dboard for vacuum tube experimentation.
I found these 9 pin vacuum tube prototype boards on ebay:
EDIT: I made a full scale breadboard (br3dboard) with banana jacks with colors for a common tube pinout (12au7) to experiment. Red is for anode high voltage. Yellow is for cathode. Black is GND. Blue is for grid. Green is for heaters. Your pinout may vary. Check your datasheet. I designed this board for a common dual triode tube but it can be used in anyway you imagine.
I thought it would be a good idea to enclose my vacuum tube prototyping board just to add another layer of safety when working with high voltages (they can kill you if you're not careful). You are using high voltage at your own risk. My suggestion if you are new to this hobby is to stick with lower voltage projects (12Volts) like this one: