You asked for:
1. Two presets coming out of the H90 in stereo to both amps
2. Two presets being routed to one amp while running the second amp dry.
3. One preset to both amps in stereo, the other preset only directed to the second amp.
The simple answer is no, the H90 cannot do ALL of these configurations on a program basis. However, each configuration is possible by itself.
#1 is self explanatory as it just requires us to connect the outputs of H90 to each amp.
#2 would require running a wet/dry configuration where you would need to dedicate an insert on the H90 as a splitter and send signal from Out 3 to one amp, while the other wet amp uses Out 1. This configuration is explained in this video: https://youtu.be/0G_WtfUatSc?t=786&si=cfHsVeGn_4Moz9Yp
#3 is not possible on the H90, but we can get close in mono. If you create a parallel path on the H90, you can place an insert after one of the two presets. Use Out 3 to connect to one amp, and the second amp connect to Out 1. This configuration will allow you to mix both presets to one amp, but only have one of the two presets to the second amp. This configuration is shown exactly at 19:34 of this video: https://youtu.be/0G_WtfUatSc?si=oQYhuAgO5765liJw&t=1174
Again, since all of these configurations would require reconnecting the H90, it’s not possible to do on a program basis.
