That would be the Signature series if it has Bob's name on the faceplate. This is the bigger ( and better in my opinion ) model. As far as factory mods go to this unit, i don't know if they do the "low impedance" aka "Apogee mod" to these or not. In terms of aftermarket modifications, i'm quite certain that you could find someone to get inside the unit and swap a few parts in order to take your money. This is true regardless of what type of product you have, the name on it or what it costs : ) Sean
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