- Huygens Optics[1] : Retired Philips' research scientist that worked on OLED development and makes highly detailed videos on different subjects, all relating to light (eg: Making optical logic gates using interference, DIY photolithography, Making a Mirror with a Variable Surface Shape).
- Marco Reps[2] : German guy doing electronics videos, usually about precision/exotic instruments (eg building a CERN open source 8.5 digits voltmeter, High speed thermal camera, Detecting cosmic rays with a raspberry pi). Has the same type of humour as Tom7
- Styropyro[3] : Laser hacker, creating stupidely powerful lasers (think 100W continous handeled laser)
- CuriousMarc[4] : Guy working on restoring old 60-80s electronic/computer equipment. Is most known for his ~25 part series on restoring the Apollo Guidance Computer. As a sidenote, Ken Shirriff, which writes die reverse-engineering articles at righto.com (which frequently pops up on HN), frequently appears in his videos.
- Scanlime[5] : Highly detailed reverse-engineering/hacking/explanations videos. Sadly she isn't that much active anymore.
- der8auer EN [6] : German guy doing mostly videos about CPUs/motherboards (think insane overclocking, etc). However he has a few hugely detailed gems, such as demonstrating how 7nm chips are troubleshooted, by probing them under a SEM[7]. Also as a sidenote, he shoots all of his videos twice, once in german and once in english, instead of just dubbing over them, which is an insane dedication imo.
- Applied Science [8] : Relatively well known channel, describing various experiments that he does in his home shop, like : Building a LCD, Silicon wafer etching, DIY mass spectrometer, etc.
- Cathode Ray Dude [9] : In-depth technical videos about mostly vintage video gear, which at first glance you wouldn't typically find interesting. Same kind of nerdy humour as Tom7
- Technology Connections [10] : Hard to describe the style, mostly videos about technical subjects, going much more in depth than you though was possible, with a really nerdy/dry humour.
I might have missed some, but those are the main ones that comes to mind.
[1]: https://www.youtube.com/channel/UC26YLK0OEbLB3TCYxGh8xVQ/vid...
[2]: https://www.youtube.com/channel/UC1O0jDlG51N3jGf6_9t-9mw/vid...
[3]: https://www.youtube.com/channel/UCJYJgj7rzsn0vdR7fkgjuIA/vid...
[4]: https://www.youtube.com/channel/UC3bosUr3WlKYm4sBaLs-Adw/vid...
[5]: https://www.youtube.com/c/scanlime/videos
[6]: https://www.youtube.com/channel/UCGsaijjOJshS2_ZmMNZgS-g/vid...
[7]: https://www.youtube.com/watch?v=EKb3OAoGeIw
[8]: https://www.youtube.com/c/AppliedScience/videos
[9]: https://www.youtube.com/c/CathodeRayDude/videos
[10]: https://www.youtube.com/c/TechnologyConnections/videos