Questions on Preamps

[Richard Pearson]

So in my search for KS, I have come across a few different preamp options, the newer 3 bands, and the older 2 band(which I have seen them listed saying the "sought after 2 band preamps") What is the difference tonally between the 2? My bass teacher(bass player for Bettye Lavette) has one with the 2 band, and I love the tones he gets out of it....to my ears he can get the sig KS tone, and also get some darker, warmer tones out of it. Also what is the control layout on those, I notice one knob is double stacked. Thanks!!