[abrugsch]

one starting point is to try and build one of the simplest synth components on the MFOS site (IIRC they are categorized by difficulty) as mentioned in my GP post, the MFOS explainers are incredible. But it does also help to have at least a little background in electronics. I started out by messing about with stuff as a kid (having a dad that was a ham helped) then eventually doing an EE degree at uni.

Fast forward 20 years and I didn't use the EE part of my degree in a career path except for the software eng part so I'd forgotten most of the theory. However the MFOS troubleshooting guide (for the WSG, and I assume most/all of their self build kits) is absolutely comprehensive, telling you exactly what points to probe and what you should see in a step-by-step logical progressive manner. You do definitely need a scope though.

For debugging analogue synths, you could probably even get away with a $25-40 STM32 based one from aliexpress as you're typically checking for DC voltage levels and human-audible waveforms ( < 20 KHz and probably realistically ~1-5 KHz) and the cheapest of cheap scopes can handle that.

so to recap:

tools:

reasonable to good multimeter - DC/AC voltage, current, resistance, continuity. (doesn't have to be a eevblog couple of hundred bucks one, but auto ranging would be useful, an audible continuity beep is a must though as is a diode check.)

Oscilloscope. for doing analogue synths, anything capable of displaying a waveform($). for anything else, the more you can budget the better. for debugging digital electronics you'll probably want multi-channel ($$) and/or MHz of range($$$). For doing RF, you'll want GHz ($$$$$)

Logic Analyzer - for digital electronics and reading the logic levels on multiple paths (bus lanes) at the same time.

Bus Pirate - for analyzing and debugging the content of various serial busses like I2C, SPI and CAN etc. not necessary but makes things easier than trying to do it with a scope or logic analyzer alone.

most importantly -

Curiosity! cannot overstate this enough, as most of the process would be very frustrating unless you have the innate curiosity to push you through.

Resources:

MFOS site in the OP. build guides with ELI5 level explainers and comprehensive troubleshooting guides

EEVblog youtube channel[0] (especially his older stuff) and forum [1]

Great Scott Youtube Channel[2]

BigClivedotcom youtube channel[3] for some hilarious teardowns and circuit explainers once you have a few videos of those in your watch history, you'll start getting plenty of relevant recommendations of other EE-tube creators

[0]https://www.youtube.com/playlist?list=PLvOlSehNtuHsCTtj-T_vk... (just one of many suitable playlists) [1] https://www.eevblog.com/forum/ [2] https://www.youtube.com/playlist?list=PLAROrg3NQn7cyu01HpOv5... [3] https://www.youtube.com/@bigclivedotcom

[jnovek]

Part of my problem is definitely understanding some aspects of these circuits on a deeper level.

I haven't done any MFOS builds but I have done a few "cores" to various synth modules (Moritz Klein's youtube is great for this) on the breadboard -- most successful was a square wave oscillator based on a schmitt trigger -- but often I'm overwhelmed by the supporting circuitry which is sometimes more complicated than the core.

For example: I cannot get my head around the design of an exponential converter.

I have trouble understainding the feedback loop between the two transistors. Ignoring that, even, as far as I can tell it creates an exponential relationship between voltage and current. However, my schmitt trigger is voltage-controlled, so don't I need a transimpedence amplifier of some sort to get back to voltage? But I can't see anything that looks transimpedence amplifier in the diagram...

I constantly feel like I have about 1/3 of the knowledge I need to proceed.

Perhaps I just need to accept certain things are outside of my understanding right now?

[abrugsch]

TBH I didn't understand any of the concepts you mentioned, and that's with background knowledge. So I'd say you're definitely talking about way beyond the basics concepts that understanding of will only come after learning the basics and then targeting your learning at synth specific designs, which will take a lot more time and discipline than a HN post can cover. I don't have that knowledge or resources to point to unfortunately (any any book covering the topic is likely 2" thick in dead tree format...)