Jon,
Marc just said where the SSM2017 should have been there was this TL072P chip. This is when we realized it is completely different. DO you know a better chip that can replace the TL072P chip? From what I understand from a quick search, the TL072 design is 30 years old!
ANDY
Andy,
1000s of postings on the net concerns themselves with issues related to replacing dual opamps and their "sound". The TL072 is a dual voltage feedback opamp with JFET inputs. If it is in a critical position (especially input device responsible for gain) it's replacement must be considered carefully.
Along with power supply issues (and possibly signal coupling caps) this will very fast become a "warm, hard, precicion, lousy, poor, noisy, silent, ...... mod".
Among the more popular standard opamps are devices made by BurrBrown/TI, Analog Devices, Linear Tech, National, ON (Motorola), Philips (NE5532), Fairchild, TI, NJM .. the list is near endless.
THAT Corporation makes some specialized devices and Elantec (now Intersil) was one of the pioneers if memory serves, behind current feedback.
See DouglasSelf for some interesting info on opamps (albeit his list is not complete nor updated)
http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm Of the JFET flavor any of these will fit the bill OPA2604, AD712, AD8512...
But again, finding the optimum device requires detailed knowledge of the circuit, application as well as
experimentation and listening test.
Best of luck
Jon