Research: Artifacts in the signals through the Casio 3500 INI (547 00866) Answering machine

The very old answering machine

Today was another usual day, I was cleaning up mess and making things more organized. As a simplistic work place = less confusion. That’s when i came across this old (working condition) casio answering machine! The first thought in my mind was, “Why not pass an audio signal through the tape and see what we get! So, I’ve ripped it apart and trying to figure out the schematics of the circuity which is hard to find on the internet as its really old!

What i intend to do with this project, is the run different sounds through the signal flow of the system, run it through a frequency analyzer and get more insights in the interesting characteristics the answering machine would add to the sound. I would mostly use since waves at different frequencies to make things easier to identify.

So While I try and find the blueprint of this thing, I am pretty much using the trial ans error method. The only thing I want to use from this is the tape and the artefacts caused by the tape along with the frequencies / distortion if any at the speakerphone. If you have any ideas, insights, I would love to hear them!

Could i use this is my signal chain?