I picked up some koss HD50's from the thrift store for $5 yesterday. I put some C batteries in them, and they work and sound great.
Problem is, C batteries are quiet expensive.
Koss gives you part of the specifications, they're 9V speakers, but they dont work with a 9v adapter i have.
What amperage are they? and if anyone knows where i can get this power adapter, please tell me.