DBX BOOMBOX- SUB HARMONIC SYNTHESIZER. Here's a great old piece. All original, with wood sides. It's a Model 100, with control for low frequency boost, sub-harmonic level & a bypass. On back you have 2 RCA in's, 2 RCA out's, 2 optional to L.F. amp RCA out's, Normal / L.F. Amp switch, and a low level threshold adjustment