Related to What's the uA741's appeal?, a lot of schematics use this rather dated opamp. My follow-up question would be: What is a good alternative?
Of course if you have specific requirements you just search for the correct part. What I'm talking about is, what should be the default opamp I stock in my parts bin?
Imagine the average hobby project with a breadboard and an Arduino, single-supply, probably 5V, frequencies in the audio spectrum, and accidental shorts.
It should just be a nice, single-ended, well behaved (no phase reversal) opamp with a large voltage swing (preferably rail-to-rail), and reasonable performance for audio.
Some comments on the linked question mention LM358 and LM324, but I've read the low slew-rate may be bad for audio, which is what most of my analogue signals are.
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In complement to Andy's list of criteria, I'll add that most of the time, one of the usual suspects will do just fine.
For example:
Microchip makes opamps? Well, yeah. They have a whole line of CMOS opamps which do absolutely nothing spectacular besides being cheap, RRIO, low-power, low-voltage. These work on 3.3V and 5V so a good match for Arduino, Pi, etc. If you want faster, try MCP6292 (10MHz).
Good thing with these cheap crummy CMOS opamps is they work well on battery voltages, and they don't have the LM358 gotchas, like the input common mode going to GND but not VCC, or the output being "kinda able to go to 0V but only if it never has to sink any current" and the like.
Yeah, there are other $0.50 RRIO opamps which would fit the bill. Do I want to spend 2 hours selecting a 50c opamp for a hobby project when I know this one will work? Probably not...
Also, cost. For amateur, hobby stuff, you gonna spend hours laying out that board, so when performance is needed, it's not worth it to skimp on the parts! Get a $3 opamp if it saves you a headache, it's well invested...
For example, if you want to filter and buffer a DAC or a PWM from an arduino and get a 0-5V output, there's no excuse for using an opamp which needs a negative supply voltage when you got 30c RRIO opamps which will do the job with only a 5V supply!
Audio, for example: if you need cheap, NE5532. If you need high quality, OPA1642, OPA1652, LME49720 and others in the same families are very good.