I just completed the restoration of a Nakamichi 582 cassette deck, it had four NJM4558 opamps, I pulled them and installed sockets. Now I have NJM5532 in there.
I understand the PNP/NPN difference on the inputs between a 4558 and 5532 (the 4558 is PNP input, 5532 is NPN). My question is where does it really matter and what are the effects? I also put 100nF capacitors on the rails of the sockets to inhibit oscillation.
This is IC303 in the Nak 582 (record amp). C124, 1uf at the +input has been replaced with film. C123, 10uf at the - input is still a polar capacitor wired as original. There is a NJM5532DD in place of the 4558. I do have some NJM2068 (PNP) opamps and pop one in here, and I probably will.
I have been told that when changing a PNP input opamp for an NPN the capacitors on the inputs should be reversed or non-polar caps should be used.
What would the effect of C123 still having the original polarity have on the function of this circuit?
I understand the PNP/NPN difference on the inputs between a 4558 and 5532 (the 4558 is PNP input, 5532 is NPN). My question is where does it really matter and what are the effects? I also put 100nF capacitors on the rails of the sockets to inhibit oscillation.
This is IC303 in the Nak 582 (record amp). C124, 1uf at the +input has been replaced with film. C123, 10uf at the - input is still a polar capacitor wired as original. There is a NJM5532DD in place of the 4558. I do have some NJM2068 (PNP) opamps and pop one in here, and I probably will.
I have been told that when changing a PNP input opamp for an NPN the capacitors on the inputs should be reversed or non-polar caps should be used.
What would the effect of C123 still having the original polarity have on the function of this circuit?
