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by gwbas1c 54 days ago
I still wonder if the circuitry was analog or digital, though. That could have been an analog "computer".
2 comments
lebuffon 50 days ago
In my case it was around 1975ish. There was no digital circuitry in signal paths then.

If you are asking how the thread pitch motor controller was working I have no in depth knowledge but it would likely be an analog envelope detector. (simple RC filter/integrator would suffice) That would be rectified to make a DC control voltage and the control voltage would be used to modulate the power to the motor in an inverse fashion. ( more audio signal -> less power )

No digits would be harmed in the process. :)

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lebuffon 50 days ago
The RIAA equalization curve for recording and playback, was typically implemented with only resistors and capacitors. No DSP required.

I know I know. It's so hard to believe you can manipulate signals without a processor. ;-)

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