the 383 was for a small amp im looking to put together. the current living conditions have me with attached neighbors, wouldnt appreciate me using the big guy. the 4558 is a dual op amp, it for a selectable distortion cuircut inside the amp, it an, iirc, "ultimate fuzz" plan.
like i said, im not too knowledgeable on the design front, so i dont know if an op-amp is called for in a cuircut, if i can replace it with just any, or what parameters to look for. most of this kind of info is over my head, for what im doing. thats why i was searching on the net!!