what is the impedance of line in/mircophone input port and impedance of speaker output port of laptop soundcard? typical values would do.
Over a year passed, I know - however :
- as John said, depends on the hardware of the soundboard ;
- however, there will be some exceptions. One of them is my ASUS Xonar D1 soundboard, where Cirrus Logic CS4398 is the DAC;
according to the specs, Zout = 118 ohms (datasheet), but I measured 99 ohms .
The line input has a relatively low impedance of 3.8-3.9 kohm (datasheet), and I measured 3.65K.