[makomk]

There are some cheap DC-powered soldering irons in a similar form factor which use a dial and potentiometer to set the temperature and an op-amp for temperature regulation. No processor in sight. Apparently they work reasonably well.

[outworlder]

Does it give you a digital display of the temperature (in Celsius or Fahrenheit, configurable)? Does it sleep if not moved? Can it run off a battery pack and monitor the power of said battery pack to safely shut off?

Not everyone needs those features. If you do or want them, the moment you add even the simplest logic, you are better off getting a microcontroller already. No reason to bother with discrete logic chips anymore.

I have used for many years a standard soldering iron (not even a soldering station) with zero logic whatsoever. It worked, but nowadays I prefer to be able to set the exact temperature I want, to the degree. And to be able to monitor if the iron is able to handle the thermal mass I'm trying to solder.

[CameronNemo]

I look at analog audio processing gear sometimes... so expensive. It really holds its value, unlike the digital hardware and software.