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A TL071 has a typical noise of 18 thingies. An NE5534 has a typical noise of only 3.5 thingies. Much less noise and its pins are the same so nothing needs to be changed to use it.
the only think it did there was to reduce the signal out of the first opamp, so requiring a third opamp for further amplification. I do not think the hiss is considered as some hind of high frequency oscillations ?What does crossed out R4 in the post #1 schematic mean? Removing this resistor is a really bad idea, creating a strange frequency response and possibly oscillations.
Low-pass active filter. It's second order due to having two capacitors. I believe it's Sallen-key type, reputed to do the job with low parts count.
View attachment 158699
Signal from tape head is very low amplitude. By finagling with resistor values you can achieve higher gain. However it's tricky to try to do everything in one stage. Sometimes it's better to to build a second stage for amplification before or after the filter stage.
R4 is required to set a useful gain in inverting OP configuration. Why are you ignoring the basics of OP circuit design?the only think it did there was to reduce the signal out of the first opamp, so requiring a third opamp for further amplification.
R4 is required to set a useful gain in inverting OP configuration. Why are you ignoring the basics of OP circuit design?
The two 220pF capacitors and the 180k resistors are lowpass filters that cut frequencies above 4kHz each. Then the response drops above 2khz.
The NE5534 opamps do not work properly with filters like that so put back the TL071 opamps.
I remember now that when I played with cassette units 56 years ago that they used pre-emphasis and de-emphasis equalization like phono players (remember them?) and FM radio.
During recording, the low frequencies were cut and the high frequencies were boosted. Then the reverse during playback the low frequencies were boosted back to normal and the high frequencies were cut and the hiss produced by the tape particles was also cut.