The lowly 2N3904

[ElectricDruid]

I think I should be getting my transistors from Mouser instead of Amazon!  These knock-offs probably are "off spec".

Quite likely. I've tested modern transistors off the same piece of tape and the matching from one part to another is generally very good. Good enough that if I was building a Moog filter, I wouldn't bother matching them. Other people might be more fussy, but I'd just label any remaining inaccuracies as "character" and leave it at that! Modern processes are so much better than what the 1970s had that even "unmatched" parts if they're from the same batch are likely to be very consistent.

But if you buy random parts from Amazon or eBay, all bets are off, obviously...

[Sparky]

I'm mostly concerned with the basic construction of the transistor.  Something made in China in 2022 that costs  $ .25  on Amazon is probably not made of quality stuff.  If it is indeed made of the same materials and the only difference is the cost of the labor then somebody please tell me!   As far as the HFE being the same for an entire batch of transistors....wellll....I've had orders of 3904's that were mostly the same [around 200-ish HFE] and 3053's that were all over the map  [20 - 100 HFE].    If a Chinese 3904 and an American 3904 have an HFE of 100v and they both sound the same in a FF circuit it'll be fine with me.   I'm not sure they do, though.   [of course there may not be ANY transistors made in America any more.....]

[Onion Ring Modulator]

I like 3904s in a Big Muff. The lower gain cuts down on the over abundance of bass.