I intend for my new Fender Rumble 100/12 to double as an amp for my 6-string nylon electro-acoustic guitars. Given the breadth of available settings, I'd like to hear from any other bass/six-string players who think they have found optimum settings beyond just turning down the bass and low-mid EQ.
Since I tend to prefer my amplified guitar tone with at bare minimum A nice verb I'd be tempted to just run a multi-effects pedal Zoom A3, Zoom G1on, or other mfg. equivalent, and port it to the auxiliary input. This lets you keep the bass intact if you're using both at the same time. I don't have a Rumble 100 (yet), but I used to use my Peavey Minx 110 for multiple instrument use the same way, basically using the amp as a stage monitor and using a DI to the main PA.
Here is my previous opinion with Rumble 200/150. I been use Strat, keyboard and digital drum play through the Rumble and i am very impressive with the result. The strat i play along with Digitech effect pedal and Valeton Dapper. I engage the bright button and Horn ON, Gain full roll back, Bass on 9, Lo-MID on 11, Hi-MID on Noon and Treble on 2. Above setting is keep the Strat in clean and clear sound, then let the effect pedal to colour the tone . Hopehelp