Vintage three band range expander in very good condition.
DBX has been the premier manufacturer of Studio grade Compressors/Expanders for over 50 years. The 3BX is for recording and transferring vinyl and tape. It brings out sonic qualities that you will miss without it.
Frequency response: 20Hz to 20kHz
Dynamic range: variable 101 to 115dB
Total harmonic distortion: 0.15%
Maximum input and output: 6V