I'm building an audio circuit and need a comparator. I've explored using an op amp for this purpose but my TL072 doesn't seem to have a high enough slew rate which resulted in latency. Instead, I've been investigating using the ubiquitous 555. It has two internal comparators and by tying the positive input of the upper one to Vcc (pin 6) I can manipulate the digital output by sending a signal to the lower one (pin 2). My problem is this: The input signal begins to clip when the voltage reaches the transition point (1/3 VCC). I've attempted remedying this with an emitter follower between the signal output and pin 2 but without luck. Any ideas? The 555 is an NE555.
Edit: I misidentified the op amp I was using. From memory I wrote it above as a 'TL072' but it's actually a 'TLC27'. This is at least consistent with @WhatRoughBeast's point about the TL072's slew rate. At any rate, I swapped it out for a TL082 (and I checked the labelling on that one) yesterday and it worked fine. Given that this method is simpler than the 555 route (no worrying about varying input impedance/flip-flop logic) I'll shift my approach and use the TL082 instead.