Poparad
Power User
This could either be a drive or amp block. Channel 2 from the Aguilar AG500 bass head, which a few years ago was exported into the AGRO stompbox is one of the best sounding bass overdrives out there. Maintains a full low end for bass guitar without getting muddy or thin like most guitar overdrives on bass. I don't know anything about the circuit design and whether or not it's close to an existing drive or amp block model, but it's my favorite bass overdrive.