Make: contributor I-Wei Huang (he of Crabfu Steamworks and Skylanders fame) sent us this cool little hack which allows you to turn an inexpensive plug-in guitar headphone amp and a vibration speaker into a practice amp.
I-Wei plugged his VOX AP2AC amPlug AC30 G2 guitar headphone amp into his acoustic guitar. Then he plugged an XDREAM X-Vibe vibration speaker into that. This type of speaker uses any sound-reflective surface as a resonator. In the video, I-Wei shows how he places the speaker contact on the back of his guitar and uses the acoustic’s hollow body as the resonator (which it is already designed to do). He also shows how you can get different sounds and amplified volume from placing the contact on different areas of the guitar’s body.
In this second demonstration video, I-Wei shows how this set-up also works with an electric guitar. He first shows what it sounds like also using the sound hole on his semi-hollow-body electric. Then he runs through and demos the sound of the guitar while using everything from the couch to a closet door to a laundry basket to get decent quality, decently amplified sound. The sound produced is similar to that of a cheap practice amp and is loud enough for practicing, even on an electric. You could also, obviously, use this set-up to amplify any instrument that has an audio output.
The two pieces of hardware that I-Wei used, the Vox AP2AC amPlug and the X-vibe speaker, can be had on Amazon for just under $35. Try finding a comparable practice amp for that. And with these two devices, you also have a headphone amp and the ability to create a speaker for any audio device using any available sound-reflective surface. Nifty!