I've got a Carvin amp with the R600 head, which like a lot of popular amps now, has lots and lots of knobs and switches on it for controlling the sound. Mine in particular has for starters, the 3 pre-shape buttons: low boost, mid shift, and high boost. Then, there's the 3 EQ knobs, low, mid (with sweepable frequency), and high. Then you have the 9 band equalizer sliders. This (or something similar to it) seems to be a pretty common setup on most amplifiers now. My question is, why are so many different kinds of controls needed, and when do you use which ones (3 band vs. 9 band eq, etc.)? I figure they wouldn't be there if there wasn't a good reason for having all the different kinds of controls, but I haven't seen a good explanation for how to use them anywhere. I did a little searching on this, but couldn't find much talking about it here (I'm still pretty new to this site, and still not very good at digging through all sorts of old threads with the search function). If anyone could explain this to me, or point me to some previous thread or an article about it somewhere, I would greatly appreciate it.