I can't hold back any longer. Must spod!

The psu in your speakers converts 100-240V AC to a series of DC voltages as has been said above. You'll normally see 5V (and nowadays 3.3V, 2.5V and 1.8V and even 1.2V) for digital. The low power analogue normally runs off about +-15V, and the power amps use higher voltages to keep the current reasonable (+-30V to 60V).

All these are DC. This is how it gets converted (and this is important).

1) First a transformer reduces the voltage to the intended values.

2) A rectifier circuit converts the 50/60Hz AC to a pulsed half wave 100/120HZ DC (technically) supply.

3)

861v8, DSP5200, DSP5200HC, DSP5000mk2, UHD722, MF10, Prime, Prime PSU