In your synthesizer wall of sound, every module represents a brick that?s capable of producing mind-bending noises. The range of sounds that you can create with synthesizer modules is unlimited, so how big your wall grows depends on how much time, money, and space you're willing to dedicate to it. Every structure requires a solid base or foundation, and in a synthesizer, this is comprised of power modules that deliver the AC and DC currents. Oscillators make up another important section of the wall of sound because they generate the waveforms that you need in order to create sounds. Filters let you tinker with the harmonics of your audio signals, an amplifier lets you control the amplitude of your audio signal, and an envelope generator controls oscillators, filters, amplifiers, and other modules. These are just a few of the module types you can find in both new and pre-owned condition on eBay, so even though you don't necessarily need a large synthesizer wall to become completely immersed in the world of electronic sound and music, that doesn?t have to stop you from building one.