VFD...they're nice displays... I have one in a converted HTPC that is gutted and has moode and a pi hidden inside. It shows track info.
I doubt there is anything available from gpio to run this.... you almost need 2 output devices specified in MoOde.... the connection for your dac...usb or I2S... and also routed to the Pi's onboard analogue out... don't know if that is possible...
I would be inclined to use the how to I linked with a bigger display...like the 2.42" Remy has...they run I2C and will be more accurate/responsive plus you get all the other info too..
https://www.ebay.ca/itm/I2C-2-42-128x64-...2749.l2649
https://www.youtube.com/watch?v=Lx8KunB0ka8
