On creating a practical 25 volts DC source with four 4LR44 batteries

Attention: At your risk: Even 25 volts can kill. Please take all safety precausions including the left hand to the back pocket (this avoids an accidental electric current through the heart). Please also use a suitable fuse in series with a battery to avoid a fire or burn hazard. Today four 4LR44 6volt batteries were carefully inserted inside a Bulgin 2x AA battery holder, with left hand in back pocket and without touching any metal part with the right hand. Although batteries are about 1mm thinner than AA batteries, the length of four 4LR44 is the same as two AA batteries and it gloriously worked. It should be good fun to use such source of voltage for JfET 2SK170 pres, DC90, DC96, DAF96, DF97 etc electron tube Pleiades V6 1H4 type pres with Pleiades bias or even open grid? 1H4 has been found to be a miracle of low noise at 12V anode potential with grid at space potential.