You don’t necessarily have to grab more algorithms right away. It’s nice to have those options, but you might be able to cover it with what you have. In a live context, and with guitar amps, some of those nuances between algorithms will get buried. You can preview the ones that really interest you (5 min. / day), and determine what your ‘must-have’ algos are over time.
You can split the Wet / Dry in the H9 Core itself (newest firmware), if you’re running in mono. In the preset below, I have Left / Channel 1 running wet (your Fender), and the Right / Channel 2 set to dry (the Marshall). There’s a section in the updated online manual on how to do this, and more information in the H9 Control app [Pedal -> General Settings -> Routing]. No need for another device.
If you like the EchoPlex inline with your wet amp, then turn the PRE DELAY settings in my presets from 100 ms. to 0 ms. I was building that slap delay into the presets themselves. Of course, if you have a better spot for the MXR, a PRE DELAY parameter is built-in to most H9 reverb algorithms.
So, you mentioned a factory “GuitPlate” preset. Can I assume that you’ve added the Plate algo to your H9 Core? I didn’t reference that particular preset here. I did more of an A-B test with my Room and Hall presets above, and tuned in a similar Plate preset by ear. It might need some work, but it’ll give you a starting point. The key is to disguise some of the very things that make it a Plate emulation.
While we’re on the subject of Van Halen, there’s a very powerful algorithm that comes with every H9 Core: H910 / H949. Here’s a recent thread with settings for EVH-type spread detuning. I can tell you that similar presets sound great in a two-amp / stereo setup.
