Came here to post this. Objective 2 is a headphone amplifier revered in the DIY community. Although, you probably won't name a piece of great engineering an invention, but what puts it aside is that it was maid freely available under Creative Commons license.
Although it was BY-ND type, which lead to some interesting results, mentioned in a link posted by parent. In my opinion some type of copyleft license would suit better, but CCBYND fixes and underlines NwAvGuy's contribution for years to come.
Although it was BY-ND type, which lead to some interesting results, mentioned in a link posted by parent. In my opinion some type of copyleft license would suit better, but CCBYND fixes and underlines NwAvGuy's contribution for years to come.