The BSS AR133 is housed in a rugged aluminium extrusion case, with robust polyurethane end-cheeks which give the AR-133 a very distinctive look. The arched case allows cables to run back underneath the unit from the end for neat cable management.

Input connectors are both 1/4" jack sockets and an XLR socket, the latter meaning that the AR-133 can be used to convert unbalanced signals to a balanced output on XLRs throughout.

Input attenuation is 0, -20 or -40dB, making the box suitable for instrument, line or amplifier levels on inputs. On the output side, a ground-lift switch is provided for quick solutions to ground-loop problems.