Panasonic KX-TC1872B Service Manual page 61

KX-TC1868B / KX-TC1871B / KX-TC1872B
15.5. Reception Signal Circuit
The received signal from the base unit is output from pins 33 (SPN) and 32 (SPP) of IC201 (DSP) as the voice signal. SPN is the
inverse output of SPP, and the speaker is driven by SPN and SPP. CN203 is the headphone jack. When the headphone is
connected to this jack, the output to the speaker of the handset (SPN,SPP) is cut and the voice signal is output to the headphone
(HSOUT) only.
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