unique and rare stereo bbd delay reverb unit. completely refurbished and restored last year, replacing all the capacitors and cleaning up the unit. the only issue remaining is that the right channel output is very slightly quieter, like 1db, which can be adjusted for using the return outputs on the front panel. these outputs sound better than the effect outs on the rear in my opinion. various combinations of the modes create different effects where the dozens off bbd chips all interplay with each other.