In general, I try to leave the advanced parameters alone unless there is some specific thing I'm trying to address. With the FM3, I haven't felt a need to do much, things sound so great with just the conventional Amp Block controls and a well chosen highpass setting on the Cabinet Block: what I have done with the advanced parameters is on the order of personal taste.
The speaker compression and drive parameters I almost always tweak a little, depending on how the preset is gain staged. I like more speaker compression on a high gain tone, not much on most cleans. These make a big difference to me on a Blackface Deluxe for example, not so much on high gain amps: depends on the IR as well. Its rather different than using a compressor in the effects chain, and well worth knowing your way around.
There are a few amp models where I prefer the character of a different preamp tube. EL84 amps, in particular, I fuss with the preamp tube choice.
Sag or preamp hardness will be adjusted once in a while, usually as a guitar specific adjustment: tightening up for a resonant 12 string (figured this out on the AX8).
With the amp block controls, I get close with the Authentic controls before moving to Ideal: With no negative feedback amp models, I find myself boosting treble and high treble and then smashing it back down with the high cut to finesse the high end character much more than would have been possible with hardware.
Although I did a fair bit of deep diving with the AX8, I doubt I'll have the desire or need on the FM3. Amp models are ready to go with basic adjustments, easy to concentrate on the music without having to tinker: There's certainly a lot an adventurous person could do, which can even amount to virtual amp redesign. I haven't had the FM3 for long. I dialed in my base line everyday sounds presets, and have mostly just been playing, haven't taken the time to really know my way around it yet.
I did recreate one Amp Block Preset I really enjoyed on the AX8 - swapping a Fender Brownface tonestack into a Hiwatt (as a lazy man's Alembic F2B into DR103) for some Gilmour like tonalities. Sounds great and hardly had to do thing. Hmmm, second thought: I may again be fighting temptation: If the advanced parameters are this easy to mess with and get a good result, I may again be lured away from music and into sound design.
Guitar sounds have been straightforward to craft. Getting a bass guitar dialed in, though, has been taking considerable effort to go that extra tonal mile beyond "sounds really good" to "truly fabulous". Several reasons for this, personal preferences which I won't get into, not a criticism of FAS or the model selection which is more than adequate.The Ideal Menu, advanced parameters and GEQ are all essential to making this work well. I don't doubt I'll eventually get exactly what I want. Much of this has to do with getting the desired string to string tonal character and balance given the resonant quirks of each specific bass and its pickups, string type, and the range of dynamics. Different presets for each bass, for sure: but it seems like each dedicated preset will be able to pull everything I need from each bass, given the 4 channels and 8 scenes.
I do tweak a few things on the ideal page, but I don't use most of the available parameters on that page yet or all the other pages until I have some kind of basic understanding of how to use them. I have a lot of reading / learning / experimenting to do. Maybe I'll take a few parameters a week and try to figure out how I could use them effectively. It's going to take a long time at that rate...
