Great to see a Project14 focused on Op Amps: Op-Amp-a-Palooza.
I don't have time to do a clever and innovative project, but looking forward to see what other members come up with.
It got me to thinking about when I first started out using IC Op Amps back in the early 1970s. First started using the uncompensated 709s and 308s and then quickly moved to the compensated 741s (1MHz was sufficient for most of what I was doing and these were inherently stable, although the early ones from TI were prone to latch-up).
I have a collection of vintage parts (709, 741, 747, 558). I was surprised that I did not have some 308s - probably stashed somewhere else. Back in those days the parts were sometimes hard to get at a reasonable price, so I resorted to buying unmarked and sometimes untested parts and testing them myself. I would use a Sharpie or scribe to mark the parts after I tested them.
Here's a picture of some of my collection:
A range of vendors and styles. Early parts were packaged in metal TO cans or ceramic DIPs (probably still are for military use) and later in plastic packages for cost and ease of manufacturing. The parts here are from Fairchild, TI, Raytheon, Signetics, and National. The earliest date stamps are 6916 for a National LM709 and 7016 for a TI SN72741. The unmarked parts pre-date those.
Those were the wild west days - I remember that we would use Motorola MECL digital ICs and would bias the power supply so we could use them as linear small signal differential amplifiers - the precursor to using these op amps.
If I find some time, I'd like to try some of these out again...
