A few things:The High/Low Cut switches are part of the “make my stage rig sound like the cab-sim” circuit, not there to emulate the Ultra Hi/Lo switches on other Ampeg amps. They are quick HPF/LPF to emulate the relatively extreme lack of bass and treble response from a B-15 cab while the EQ dials next to them are both standard boost/cut dials with the center being neutral. All 4 of these are post-amp sim. The manual shows response plots for all of these controls.
Bass and Treble come before parts of the “drive” circuit, so if you boost them you will get more drive and cut them less drive at any given Drive setting.
- You may have missed where I literally just plugged it in and got it to work. I didn't scour the manual or look at graphs. I used my ears based on my decades with a real one. I figured out pretty quick how the HP/LP knobs helped dial in a sound on my combo.
- Charts be damned, I can tell you my real B-15 never suffered from a lack of bass and treble response. It always sounded good. If there were frequencies "missing", I never noticed or cared.
- The bass/treble are part of the "preamp" section of what is a B-15. Volume (as I think of it from the B-15; it's NOT Drive ... ugh) is just how "loud" that is. The BR Fifteen has the additional Output knob which is overall volume coming out of the pedal. I'm approaching it as I would a real B-15. On my B-15 it was rare for me to ever boost bass. If anything, I cut bass. I sometimes goosed treble depending on the room.
Last edited: