A victrola style passive amplifier for a cell phone. I’m getting an 11db increase in volume from across the room, more bass and a bit of reverb, all completely unpowered.

  • Cone is made from 2 file folders joined with CA glue, and coated with truck bed liner
  • Tube is a 2″ p-trap with a 2″ thread adapter and a 3in flush fit cap, painted with hammer texture paint and then metallic oil-rubbeb bronze
  • Mounting bracket is 5/8″ aluminum flat stock
  • The back plate and phone slot are just from some scrap 2″x10″ pine I had lying around.

P.S. I apologize for the dizzying painting sections. Lesson learned I guess. holding camera + 20x speed = obnoxious

“RetroFuture Clean” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0