OK

Generally I think you're trying to do too much in too little space in the 3u racks... by that I mean not enough support modules per voice - & rememeber your inputs are also a voice..

general thoughts on micro versions of mutable modules - poor ergonomics kill enjoyment + trying to tune modules with trimmers is a hopeless and horrible task...

O&C - what do you think you will use this for? I'm not a big fan of these all in one multifunction modules - you can only use 1 or 2 functions at once and the UIs are compromised - simple functional modules are better everytime imo - although using htem as I method for working out what modules you actually need and then replacing that functionality is a valid method of learning - but then I would recommend having the free space in the rack to allow for that - which you haben't - & yes I do own a disting mk4 - it's almost always been used as a tape delay

notes from 1st rack (starting at the top):

Not convinced about the ADDAC input module... you mention both sax and bass... you'll need a mic for the sax, won't you? in which case I'd look at the befcao instrument interface... it can handle mic (including +48v phantom power), line and instrument level & has useful functionality like envelope following and gate extraction... disting ex is also useful here as it has one of the better pitch extractoin algos...

erica black output is way too big (and possibly completely unnecessary) for this size case - takes up way too much valuable rack space - but then so does the rack wart (a pet hate)

in a rack this size, if you want to use things like overdrives and compressors - I'd get a pedal interface (AI synthesis for example) and guitar pedals - potentially cheaper and don't waste rack sppace that'd be better used for more modulation, more filters, and most importantly utilities!!!

notes from 2nd rack:

as above where relevant plus - no envelope follower in disting mk4 iirc, maths - great module but rack too small for it imo, mixer also takes way too much space... other modules are too small on average... remember 1hp =0.58mm or 1/5" of an inch!!!

notes on 3rd rack:

as above where relevant plus - I really don't like these digital modular in a module modules - they're the absolute antithesis of modular synthesis to me - which tends towards knob per function & discrete modules that you patch together with patch cables etc - if you want something like this a laptop and vcv rack is a much better option in my opinion - even if it is connected up to the modular via something like an es9

notes on 4th rack:

same as above where relevant plus - kind of better in that it's bigger - but way too many sound sources!!!! see my signature!! read it, think about it for a considerable period of time... then apply what you have learnt to this rack...

and seriously consider your options when buying modules - you can give your money to known bigots (I believe the modern american term is edgelords - but I'm old and British) or you can give it to people who aren't - one modukle in this rack is from a company owned by a known bigot, infamous for making rape jokes in online forums... but it's your choice... most modular manufacturers are not in this category - as far as I know it's just 2 manufacturers...

also experience with fx aids - great modules - but imo the xl (or regular versionl) isn;t very practical without a cheat sheet - the pro is usable without a cheat sheet and if you set them up correctly the pro can be used as a cheat sheet for one or more of the other fx aid modules... screens are far better than leds for determining what algo you are using!!!

notes on 5th rack:

same as above where relevant plus - nothing that makes sense in terms of an actual modular synthesizer - all of this could be done cheaper and probably better in pedal form... nothing that leverages what modular is good at - modulation and utilities - or in terms of the effects - not a lot of modules that take modulation well or are that interesting... modulatable granular, delay reverb etc...

again see my signature: read it and think about it until you understand it... then apply to building a rack...

as a start: a sound source (instrument interface), a sound modifier, a modulation source (maths is great, see below), a quad cascading vca (you can never have too many vcas & the above racks are bereft of them) & some utilities - at a minimum something like a happy nerdiong 3 * MIA and some patch cables - buy no more than this to start! and add very slowly and with careful consideration

maths: download the 'maths illustrated supplement' work your way through it multiple times paying specific attention to how what and why it is doing what it's doing - as well as just using it as a dual function generator - it'll really help with your patching in general - not just self patching maths!!

"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia

Utility modules are the dull polish that makes the shiny modules actually shine!!!

sound sources < sound modifiers < modulation sources < utilities