AKG C451B Technical question about schematic
I have a technical question about transformerless condenser microphone ## AKG C451B.
To be honest I don't expect any answer but I'd be gratefull if there is one...
One can find easily the schematic of the C451B on the internet, for example here is the "service manual (well, not exactly... see page 5 and rotate clockwise) https://elektrotanya.com/akg_c451b_451bst_sm.pdf/download.html
The two 2k2 resistor from pins 2 and 3 "transfer" the phantom power.
My question is:
It's obvious that pin2 of XLR of the mic has the non-inverted audio signal of the mic, together of course with the phantom power.
Pin3 has the phantom power too (of course) but I can not understand how can it has the inverted audio signal, as it does not connect to the audio circuit...
The following differential stage of the preamp (mixer console or whatever) will do it's job ok because the noise/hum will be equal and in phase to the 2 wires (pin2 & 3 of XLR). Also, the audio will be present because the difference between these 2 wires (pin 2&3 of XLR) will not cancel each other (pin2 has audio and pin3 has no audio). The only "bad" result will be that the audio will be low (lower than a normal balanced audio with + and - in respect to ground).
Am I thinking right? Do I make somewhere a mistake? If this is true, then the mic (and other mics as I show in the internet) is not "true balanced". There is no inverted audio output...
If somebody knows something about it, please let me know.
I wish I make a mistake somewhere...
Same goes to C3000 (Carefull, the image is upside down...). The two 2k2 resistors here, also "transfer" the phantom power.
Thanks in advance, and sorry for the long post.