When I was probably 13 years old, I got Duke Nukem 3D. I really wanted to figure out how to build my own levels. I had found other levels online and I couldn't figure it out. My 7th grade teacher made us do was write formal letters as a project for class. So I wrote a snail mail support request to 3D Realms asking for help getting set up with build.exe. They sent me a printed version of the manual, and some troubleshooting tips for the issue I was having.
I love my TD-3 and my KO pocket operator. The comment below suggests the minifreak, and I kind of agree with them.
Behringer Pro 800 looks pretty great too, same price, analog, but fewer sound options.
Also, I'd like to say, if you're looking for a nice community for this stuff, look up EZBOT on youtube, and join his discord. It's a great group of people and they'll talk all day about this stuff with you :). And say "hi" if you join.
I'd say, if you find joy in soldering and DIY electronics, something like this could be great. It's hard to say without hearing it...
I really think a first synth (I know you already have one, but it seems like you're unhappy with it...), should be a polyphonic one. I went a similar route as you, but with a Behringer Neutron, and it was fun, but I immediately wanted something more.
Anyway, If you've got the itch for a new instrument, get a Microfreak, or a Minifreak from Arturia instead of either of these. Microfreak is paraphonic, so not full polyphony, but you can play chords, and when I use mine I don't miss having 1 filter per voice.
This is true. The basics are required for ear training. But once you get past the basics (reading music, intervals, identifying chords), I don't thinking going much past that is necessary.
I think I'm incorrectly assuming people want to take it past the basics when they say they want to learn music theory.
The Nashville Number System is faster to write down as you listen to a tune, has methods of indicating ryhthm associated with changes (underline means half a bar, diamond around a number means to play the note once and let it ring for a whole bar). It's just better all around for popular music. Roman Numerals are really only used in analyzing classical music as far as I know.
Part of my education, in commercial ear training class, we had to write number charts and get it right the first time through. It sounds hard, but with practice it's really quick.
I really think it depends on what level you're at. If you're still struggling to identify notes on the staff, then flash cards are just fine. If you're struggling to identify the intervals or triads, also still fine. If you can do that easily, then forego the flash cards and start analyzing Bach chorales.
But I'll restate what I said elsewhere, I think ear training is much more important once you get past the basics. In that case, I'd learn the Nashville Number System (https://en.wikipedia.org/wiki/Nashville_Number_System).
I agree, give Rick's course a try, with an emphasis on ear training. I think ear training is much more important than music theory. You'll learn theory along the way (intervals, chord quality, etc...) but it focuses more on hearing the difference. Most of music making is hearing a song and playing it back, or hearing a melody in your head and getting it into a daw in some way, music theory alone won't teach you that. Ear training will though!
I just want to say you missed Chase Bliss when mentioning good function and good form. Especially their Automotone series pedals (e.g. CXM1978 and their preamp). I find all of their pedals aesthetically pleasing and easy to use (with some bit of mystery akin to Eurorack like another commenter mentioned)
Honestly, google, and instagram is how I found most of the classes I've taken.
I follow a lot of spoon carvers and other types of woodworkers and they post their class schedules pretty frequently. If you're in the bay area, there is the Bay Area Spoon Carvers. Since covid, one of their members started a "Wake up and Carve" zoom meetup. People from all over get together and carve on Zoom, ask questions. It looks pretty cool.
I live in Tennessee, and East TN/Western North Carolina there are multiple folk art schools where you can learn this kind of stuff.
EDIT:
Also, I just want to say, the John Campbell Folk School is such a great place. In my high school/college years I went there for contra dances during the winter and summer.
I went to visual performing arts high school and one of my classmates was a counter-tenor. He also doubled as a baritone, which, from what I understand is fairly common. It was incredible what he could do.