Telephone recording circuit (CB21270E)

Found in an American documentation, this circuit shows how an interface should be made for recording telephone conversations with quality and safety.

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Transistor static switch (CB9287E)
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DC Amplifier with Drift Compensation (CB14068E)
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Color Code Identifier (CB16353E)
Have you not yet memorized the color code used to identify resistors and capacitors? Do you have...