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.
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've got a couple 256-button monomes (no longer in production, basically -- they only make smaller models now) and waited twelve years for something velocity sensitive with as many buttons to come around. Eventually the Lumatone did, and now the monomes sit in a closet -- but I'd really like something with smaller buttons, because I divide the octave into 58 pieces, which means I can barely reach an octave on the Lumatone (whereas I could easily reach across three octaves on the monome).
If you're familiar with hardware design, it wouldn't be terribly hard to make a big grid of pressure-sensitive buttons using force-sensitive resistor material (Sensitronics makes some that they sell approximately by the foot, possibly velostat or a similar material could work too) laid over the top of pairs of interdigitized fingers of copper, connected through a bunch of multiplexers or similar to the ADC inputs on a microcontroller. The buttons can be whatever semi-squishy material you want to lay over the top of the pressure sensors.
(I bring this up because I'm working on a similar project, but not with a regular grid. My keyboard has 113 pressure-sensitive keys. I've been using JLCPCB, who are surprisingly cheap even for large boards and even when buying in quantities of 5 or so.)
I've been looking into this (thanks for the pointer to Sensitronics!), do you have any pointers to a manufacturer of squishy material pads? (silicone I guess)
Sensitronics was recommended to me by Roger Linn one time I met him when he happened to be in town for an event. They apparently make the sensor in the Linnstrument.
What I do is I glue a sheet of 1/8th inch birch ply to a sheet of felt using liquid hide glue, then use a laser cutter to cut that into keys. (They're irregular polygons, but you could do the same easily with squares.) I have another piece of laser cut plywood (or the "negative space" of the same plywood, but with the felt removed) that serves as a frame to hold the keys in place. I use packing tape on the back of the frame, sticky side up, to grab onto the felt so they don't all fall out when you turn it upside-down. The felt gives the keys a satisfying squishy feel. Wood screws hold it all together.
In other words, from top to bottom a key is comprised of 1/8th inch birch ply, a layer of glue, a layer of felt, a layer of tape sticky side up, a layer of FSR film, then ENIG-coated copper traces on an FR4 PCB with the solder mask excluded. I also have another layer of plywood (1/4") on the bottom for structure.
I made an early attempt at using some kind of silicone rubber, but I wasn't successful. It might be doable and I imagine there are companies that can make that stuff for you but in the end I decided I liked wooden keys better and they were just plain easier.
I don't have leds on the keys, but if you want that, WS2812's are surprisingly cheap and could be placed by a pick-and-place machine by the hundreds -- if you can figure out a way to get the light to shine through all the intervening opaque parts.
I considered it! But I'm a piano player, and I like to be free to keep my hands wide apart, which I think requires more tactile feedback than the Linnstrument provides.
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'm curious; why would you recommend the Nashville Number System over Roman Numerals (https://en.wikipedia.org/wiki/Roman_numeral_analysis)? Seems like the latter is much more widely used. Maybe I'm in a different bubble than you...
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 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!
If you listen to any of Rick's videos, he will tell you that ear training and music theory are so closely related that there can't be one without other. Of course, back in the day in music school theory was taught without ear training and that made it kind of useless. Or maybe it was more that listening was never taught, it was just put in exam and if you can't write down the chords you hear there you're not going to be a musician.
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.
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.
