Here's a little "secret" tip for you guys.

[Silver Blues]

If ever you are building a drive/distortion, etc. that takes a 4558 op-amp, try swapping it out for a 4560. I almost guarantee it will sound better. I've done this to a few pedals and been far happier with the results. In my Hematoma, it helped mitigate the dark slushy clipping and give it a more defined, crisper tone. I also tried one in my D.I.G. and liked it better than the TL072 (though I decided to not leave it in there because it was my last one. I have to pick up some more lol). On the Bay you can find JRC4560 and BA4560, the ones I have are BA4560 out of some piece of broken audio equipment that's probably older than I am.

Thought I'd share

[rocket88]

nice, i bought some of those chips, and couldn't remember why. lol.

[Frank_NH]

Thanks Silver Blues.  I have a stash of dual op amps, and most can be used for IC-based overdrives that call for a dual.  My favs are the NE5532 and the LF353.