CV Meter is a very handy utility module that shows the CV level in three input ranges (+/-1, 5 or 10V). You get immediately a picture of what is the level and polarity of your modulating control voltage. My CV Meter layout is designed for EuroRack size. After I have double checked these I can order them from ITEAD Studio (http://imall.iteadstudio.com/open-pcb/pcb-prototyping/im120418002.html).
|CV Meter front panel|