Parts needed:
1. An old tape recorder
2. Two wires
3. A variable resistor
4. A blank audio casette
A tape deck typically contains three "heads" which are in contact with the tape during playback. One head erases the tape, one
records, and one plays. The basic
concept of the echo box device is to connect the
speaker to the record head with the two wires. After that, everything that is played also re-
recorded on the tape. The playback head is usually "downstream" from the recording head, which is downstream from the erase head. A
feedback loop is generated while play is pressed, because what is played is recorded, which is played again, etc. Place the variable resistor between the speaker and the record head to
dampen the
echo and avoid loud
annoying feedback. A microphone in the mic-in is used to add the starting sounds. The great thing about this simple
hack is that your echo experiments are automatically recorded for you on the tape! The tape travels at 4.76 cm/sec. Divide the distance between the record and play heads by 4.76 to find the echo
delay in seconds. You can slow the tape with your finger for more
bizarre effects.