I am curious if a BZX55C12 would work in place of a 1N759A?
I do not have any of the latter on hand (no clue why lol) but I have some BZX55C12’s (again, no clue why lol)
They seem VERY similar except the forward voltage on the BZX55C12 is 1.5v vs the 1N759A’s 1v and the Zener Impedance is 20ohms on the BZX55C12 and 10ohms on the 1N759A.
Anyone know if it would work?
It depends on your application, but if it’s just for a regulated supply, I would say yes, they have the same power rating.
If you want a precise reference, go for the one with the lower impedance, as it will be less dependant to the load current and the input voltage variations (noises).
But if you want a precise reference, don’t use these diodes, or with buffering and a trimmer.
As @telec16 says, it depends on the application but zeners are seldom used for the forward voltage properties so odds are it doesn’t matter at all 
Also the given 1.5 V and 1.1 V are max values across the full temperature range, and the typical values are usually much lower; here’s the typical values for the 1.5 V one:
Extrapolate that to 1.5 V and you end up at 50,000 A or so… (I wouldn’t recommend that).
So that zener is particularly rich in smoke!
I would. (what? that would be fun!)
lol, i got ballsy and tried it… maybe thats why its not working properly lmao…
Tried what? 50,000 amps? (you still haven’t told us what circuit you need the zener for)
no, tried the BZX55C12 lol
i mean… it works but the sample aspect doesnt seem to do anything and the LED isnt working… lol
Oh, that’s an entirely different use than we had in mind earlier – the 12V zener there is used as a noise source, by having a barely noticeable current (*) avalanche through it, and amplifying the resulting noise 200× or so. You won’t find useful information for that in ordinary datasheets.
(*) 12V/680k= 17.6 uA, so about 2.8 billion times lower than 50 kA)
Did you make sure to put the substitute transistors in backwards from the silk screen? Since the diode is just producing the noise and that aspect seems fine, that’s unlikely to be the issue
lmao no - what if it was a 2n5457?
A local friend had some of those so I tried one.
Does it need to be backwards?
The pinouts of transistors sometimes confuse the shit out of me. lol
Yeah, those also need to be backwards.
HAH that would be my problem then.
Can’t wait for work to be done 
now I have to try to finagle that transistor out of there… Good thing I left it standing a little off of the board!
I really regret not noticing the is an inline_wide version of a transistor in KiCAD lol.
I now use it.
Yeah, that’s a life changing footprint, that is.
I tried the “hand solder” and the “wide” both are nice. The standard version gives me anxiety
