I'm trying to measure my audio interface's line input impedance using AD2 with impedance analyzer PCB but don't seem to have a clue what I'm doing...
I've got Focusrite Scarlett 2i2 3rd Gen USB audio interface. Its manufacturer specifies device's line input impedance at 60kΩ (https://focusrite.com/products/scarlett-2i2-3rd-gen). I have connected one end of an audio cable to one of the Scarlett's (mono) line inputs and the other end into the block terminal of the impedance analyzer (GND/jack sleeve to "-" and signal/jack tip to "+"). I have configured WaveForms instrument as per screenshot and got a below result. Does it make any kind of sense? I realize I'm not going to get a smooth linear impedance plot over the frequency range but does this look even remotely correct? Is the phase supposed to jump around all over the place like that? Also, I keep getting the "Resistor too low!?" message in the corner of the plot area. When I'm changing the load resistor value I can hear the relays clicking but the supposed impedance's average value just increases ten-fold with each increase of R by factor of ten and the warning stays there even at 1MΩ. I can hear the frequency sweeps just fine in the speakers, the Focusrite's input level is also set correctly (solidly registering but not clipping).
Am I even using the right tool for the job or the analyzer is not meant for active inputs like that?
I am a simple guy with basic digital logic skills and steady-state electronics understanding, any help in making heads or tails of this will be greatly appreciated 😉
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ZbigT
Hello
I'm trying to measure my audio interface's line input impedance using AD2 with impedance analyzer PCB but don't seem to have a clue what I'm doing...
I've got Focusrite Scarlett 2i2 3rd Gen USB audio interface. Its manufacturer specifies device's line input impedance at 60kΩ (https://focusrite.com/products/scarlett-2i2-3rd-gen). I have connected one end of an audio cable to one of the Scarlett's (mono) line inputs and the other end into the block terminal of the impedance analyzer (GND/jack sleeve to "-" and signal/jack tip to "+"). I have configured WaveForms instrument as per screenshot and got a below result. Does it make any kind of sense? I realize I'm not going to get a smooth linear impedance plot over the frequency range but does this look even remotely correct? Is the phase supposed to jump around all over the place like that? Also, I keep getting the "Resistor too low!?" message in the corner of the plot area. When I'm changing the load resistor value I can hear the relays clicking but the supposed impedance's average value just increases ten-fold with each increase of R by factor of ten and the warning stays there even at 1MΩ. I can hear the frequency sweeps just fine in the speakers, the Focusrite's input level is also set correctly (solidly registering but not clipping).
Am I even using the right tool for the job or the analyzer is not meant for active inputs like that?
I am a simple guy with basic digital logic skills and steady-state electronics understanding, any help in making heads or tails of this will be greatly appreciated 😉
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