low power lightweight amp

[dextrom]

i want to build a small amp to power decent speakers and to plug a mp3 player into. im going to be running this solar, so thats why i want low power. any ideas?

 

[sofaspud]

What type of speakers exactly? Will this be portable? What size polar panel and battery?
Class D efficiency & fidelity seem a logical choice.

 

[dextrom]

40 w speakers from goodwill. from a bookshelf stereo i assume. i got a 5 watt solar battery charger from harbor freight. dont know what battery yet to get. would like to try to keep it portable as possible