The Ballast is really an inverter, It puts out a higher voltage which may or may not be A/C (Likely is).
As noted, some tubes are designed to use that kind of voltage,
Others are designed to work on 12 volts, if yours is, I would suggest cutting the lead..
Now, the 12 volt tubes come in two types, Some have either plastic or metal pins that are insulated and do not connect anything, others the pins are the contacts.. The ones where the pins are N/C have a pair of wires coming out of them.
on those you can simply disconnect the ballast from the ON/OFF switch and leave it in palce, (this is how I will likely do my LED upgrade).
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times