How would a one transistor Pleiades BD139 amplifier sound directly connected to a 12V solar panel

At your risk. All safety precautions should be followed. Any cottage or current can be dangerous.


A small small size solar panel about a A5 page size (folded A4 paper) should be enough. Or even a folded A5 size. After all only 50mA to 70mA is needed.


Sound can be loud with an output trasformer or a speaker of impedance matched to the output impedance of the one transistor operating in class A (electrons flowing all the time).


Sound quality can be exceptional.


A way to directly convert sun rays to beautifully sounding music.


Can the same be done for a one electron tube amplifier. A low voltage cell for the 1.4V filament of say a DL33 electron tube. Then a few very small 9V low current solar cells connected in series for the anode circuit. An input transformer (1:7?) is needed too for driving the grid with enough music signal voltage.