by carlaz » Wed Feb 01, 2023 11:41 pm
Pretty much any guitar combo (or separate speaker cabinet) is going to have speakers designed to work with guitar amps that significantly shape the sound.
If you are using a guitar combo as an external amp with AmpliTube, then the best (but, IMO, still not very good) option is to bypass AmpliTube's Cab Room so that output from the amp head section of AmpliTube is passing as directly as possible to your combo's speaker. That said, it sounds like your combo requires some kind of power amp selection; any AmpliTube amp model is modeling a power-amp as well as a pre-amp, so .... Plus, it's hard to say what "Natural" for your pre-amp selection really means. In any case, you are essentially adding at least a "second" power amp to the chain. (I mean, isn't a Marshall Code basically an amp modeler? So running AmpliTube into it is running one amp modeler into another.)
I am not familiar with the Marshall Code amps, but even if you could completely bypass the pre-amp and power-amp sections, you are still stuck with running into its speaker -- and who knows how that shapes the sound?
In short, I think it will be tough to get the Code to act as an EQ-neutral powered speaker.
In general, it is usually recommended to run output from AmpliTube into a keyboard amp or a powered speaker (or a PA). Those are intended to reproduce the signal you run into them without reshaping it (much!).