I'm designing a circuit for experimental use. I'll make this as quick as possible. Browsing other circuit designs on the web, I initially noticed "followers" placed between other op-amp app's (adders, integrators, inverters, etc). From what I can tell, putting in followers like this must be a good practice in circuit design (because it provides some kind of "buffer" throughout the circuit?). That said, why do I also see resistors (with seemingly random values) between adders and followers, integrators and followers, etc. Followers don't require an input resistance to do their job! Thus my confusion! Can't we just do without all those resistors? To help illustrate my question, I've attached one example I saw. Why did the circuit designer choose to put a 49.9k resistor between the two op-amps? Should I incorporate this practice into my circuit design? Thanks!