> In general, you can always substitute a high-quality, expensive op-amp for a cheap op-amp. Yes, it will work in general. Unless the expensive opamp has a sig

> In general, you can always substitute a high-quality, expensive op-amp for a cheap op-amp. Yes, it will work in general. Unless the expensive opamp has a significantly wider bandwidth, then one must use with caution. Switching from a low bandwidth opamp to a high bandwidth opamp is especially problematic, the loop characteristics are different and it may need additional frequency compensation or bandwidth limiting, the original layout may become inadequate, etc. More often than not, a blind replacement make it oscillate like crazy. Sometimes having a bunch of cheap opamps makes life easier. And financially - your heart and wallet won't start bleeding when your $0.5 opamp is unexpectedly zapped by ESD, cooked in soldering, or fried in an overload. Killing a $10 ASIC is a big deal (just did that last week while prototyping an ASIC controller, but there isn't anything cheaper on the market).