My ideal amp would have the cleans and overdrive of a JTM45, but also be capable of getting the raw overdrive of the jmpbass. The more I look at this, the more it seems like an impossibility. Granted, there will always be some compromises (e.g., only kt66 or el34 tubes could be used). It seems that this isn't just a question of a switch to remove/restore sag in the power supply, or some other change. It seems like everything from preamp filtering to OT specs would have to be changed. With all this in mind, it seems that my best option might be to get a jtm with an effects loop, and run something like a "Sansamp" into the return to get the JMP sound (though I don't think that they make a JMP bass sim), and use the amp as a whole for the JTM sound. Why this way rather than the other way? This way would preserve the JTM cleans, which I love. I wouldn't have any use for the JMP bass cleans anyway. So, are mods and switches possible to get the best of both worlds, or is the modeler through the effects return the more practical way to go? Thanks.