MIXERS, MATRICES, AND PROCESSING: VERY SIMPLE, VERY CHEAP, VERY CLEAN MIXERS, AND WAYS OF CONFIGURING LOTS OF CIRCUITS

Now that your collection of noisemakers is growing, a simple mixer might prove useful. Here are some completely passive circuit designs-they use no batteries, no chips or other active components; they need no on/off switches or circuit boards. Even if you already have a “real” mixer, this is a very convenient way to expand its inputs. Th e basic schematic is shown below in fi gure 27.1.