I think of the Ron Pentecost School Of Broadcasting's 'reverb workshop' by Stevens and Grdnic.
Every kid loves the echo when they first get a new system or mic with that effect! The best one was one shaped like a flat bottom ice cream cone with a spring in the bottom, and it would reflect your voice back echoed, no electricity involved.
I guess it did have a bit of old Animal Collective sound, but I heard it as the built-in tune on the Casio SK-1 keyboard.
I liked how Animal Collective evolve from drum circles to the more pop sound of Merriwether Post Pavilion, then I was hearing a bunch of bands who sounded like them.