PartyQ AC adapter mod for less than 10 bucks

It seems to me if you're wanting to charge (2) 1.5 volt batteries that you would want a power supply that produces 3 volts, not 6.
Built with 6V 1A adapter - my PartyQ is probably 4 yrs old (in 2018), now it works GREAT! Now I can use my PartyQ without thinking twice about batteries. Thanks