I run an H9000 in a stereo guitar rig featuring two Mesa/Boogie stacks. I use an RJM Effects Gizmo to control the signal flow via MIDI. I run one H9K FX Chain to the front of the amps for gain-based effects and a 2nd FX Chain to the effects loops of both amps. That gives me four algorithms in front and four in the effects loops, which is plenty for me. The H9K gives us the ability to switch between -10 and +4 dB operation and I/O pairs, so you don’t have to worry about that with an external device. I use a DB25 TRS snake from the H9K to the RJM to make my connections. I do use some Radial Boxes to make sure I’m able to isolate one side of the rig from the other in case I run into grounding and phasing issues on the amp inputs and effects loops connections. Also, it keeps the rig very quiet. I connect my guitar to the H9K via a small preamp whose output goes to XLR input 1 on the H9K as a balanced signal. Once inside the H9K, I split that signal for stereo operation. This just allows me to adjust the input level to feed the PRE Fx Chain perfectly. The rig is controlled by an RJM MasterMind GT/16.