This a Biamp MR/140 spring reverb and 4 band equalizer made in Portland Oregon by Biamp Systems Inc. The unit has XLR input and output and 1/4" unbalanced input and output. Tested and working well. No scratchy potentiometers, everything is quiet. Has Drive capability on input level control. There's also a Balance between Dry and Wet, very useful when mixing and Output level control. See photos in great shape. Thanks for looking.