Quoted from weeze:
I use a good ole 9volt battery goes on smoke detectors, etc. Gottliebs are better then Bally that is for sure.
I note that a lot of people complain about Bally components, but I have never bought Home a wedge head yet they didn't need at least 8 to 10 or more of the sockets replaced because they were just too loose and would flicker brighter and dimmer, or on and off. Gottlieb bought a few batches of questionable quality sockets at one time or another.