So now that I am back from uni for Easter, I have a fair bit more time on my hands. I have begun the process of building the entire circuit on a breadboard. This process has been rather slow because at each point I have experimented with different designs to (hopefully) ensure that I am choosing the best component and structure for my purpose.
While I am using dual op-amp chips, in order to make my life easier I am spreading the circuit out by only using one op-amp from each chip for now. The overall circuit will be clearer if I draw it out:
The circuit so far takes an input from the tape head, amplifies it and mixes it with the guitar signal. It also drives the cassette player motor.
I did have a problem with noise from the motor being transmitted along the power lines. This was sorted out by adding 10uF decoupling capacitors across the 10k resistors.
In other news I have modified the tape so that I can fit two tape heads in – one to write and one to read.