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So I am using MAX9812 amplifier to build a microphone module, but from the pic you can see it requires 3 wires, vcc, ground and output. max9812 application scheme

I was thinking to wire Vcc with output to get rid of one wire, making it a 2 wire system, is this possible without losing the amplification?

Thanks for any help.

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  • \$\begingroup\$ Welcome to EE.SE. Electric condenser microphones need about 1.5 volts of 'phantom' power, that is it shares the same wire as that which carries the very weak mic output. These mics have an FET in them for impedance matching, thus the need for a few volts. \$\endgroup\$ – Sparky256 Mar 20 '18 at 4:35
  • \$\begingroup\$ I know the need for bias voltage for ecm, but that's not my question. My question is essentially asking is it possible to wire Vcc and OUT (in the picture) together and maybe a still somehow get the amplified microphone signal on this combined wire. \$\endgroup\$ – mike zhao Mar 20 '18 at 4:48
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    \$\begingroup\$ Answer: NO . If you want a 2 wire mic , use a typ. FET buffered electret mic alone \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Mar 20 '18 at 5:39
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    \$\begingroup\$ Don't try to re-invent the wheel. This is as basic as it gets. \$\endgroup\$ – Sparky256 Mar 20 '18 at 6:12
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I was thinking to wire Vcc with output to get rid of one wire, making it a 2 wire system, is this possible without losing the amplification?

enter image description here

It's called phantom powering and works fine for balanced stage microphones and will work OK for short runs of cable connected to an unbalanced microphone but be aware that noise will eventually become a nuisance because the unbalanced microphone.

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