With the understanding that Joe Cozzi has long since forgotten waaay more about effects and Eventide products than I will ever know (I have to believe he was even one of the H90 designers) … there might be an H90 hack for your use case (minimalist work-travel).
I have been using the the H90 to drive headphones directly plugged into the H90 R+L outputs since it was released about two years ago (pro’lly several thousand hours). I do have to crank up the P-out parameter to +12dB to hear it well but I have never had a failure or even distortion. I also did this with the H9 for about a thousand hours with nothing but great results. My headphones are about 40 Ohms … something like Denon 5400.
Joe, of course, also gives the correct advice regarding amp sims. However … if you look me up on PatchStorage.com (user: apalazzolo) you’ll see a list of H90 programs called “22 Clean Blackface Tones”. I created this list for my own minimalist work-travel needs. Each of the 10 programs uses a basic reverb/delay with the EQCompressor algorithm to approximate a clean Fender amp sim. This is only an amp sim in the same way that the Joyo American Sound (or that new Earthquaker Devices mini amp sim) is an amp sim (not the best … and arguably not really even an amp sim … but close enough for travel or a back up). It does feel a bit compressed (even with the compression completely off) but with some SP2019 or Spring reverb it’s surprisingly good for something that was never intended to be an amp sim.
Good luck!
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