Typical analog noise generators make signal by amplifying AC component coming out from zener current of transistors reversely biased between emitter and base (here’s an example circuit).
Any bipolar transistor would work as such a noise source, but noise quality in listening is different from part numbers. 2SC828A is well known as good noise source, but it’s been obsolete for long. So for Analog2.0, I have been recommending 2SC3311 instead. But this part becomes obsolete as well. Now I have to find another one.