Great little amp this, I've gigged it with an upright bass in an acoustic trio, but its mainly been sat in my music room and used in lessons.
Passive active switch, 3 band eq, aux in for your MP3 player, phones out.
10" driver.
Quite old, but has served me well.
[IMG]http://i1000.photobucket.com/albums/af124/basscoach/stuffs/IMAG1397.jpg[/IMG]
More spec.
http://usa.yamaha.com/product_archive/guitars-basses/f20b/?mode=model
£30