Yes - the 2 side capsules are connected out of phase. The idea was 'borrowed' :) from Jules' great M/S instructable here: ?
?(Here's my take on the same concept: )
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That application uses 'FETless' electrets, so it's not quite the same with capsules that have integral FETs - like the EM204.
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The configuration for the mic image in my first post was this circuit, which was constructed onto stripboard:
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('rogs' is another of my internet aliases! )
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When it comes to XY it's simpler of course - there's no need to create the differential side channel.
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The P48 circuit you mentoned is really more suitable for 3 terminal capsules? - like the EM200. It is an ingenious way of creating a very simple 'balanced' input.
Turning the EM204 into a '3 terminal' capsule is possible - but not at all easy! .. Far better to use an EM200, if you are keen to use circuits like the P48?
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For 2 terminal electrets - like the EM204 - I tend to use this configuration:?
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It'unbalanced, but as the EM204 capsule output impedance is quite low, it works very well? with single cored screeen cable, with lengths up to at least 3 metres (and probably a bit more!)
( The 6v2 zener diode is included to protect the capsule from overvoltage when 'hot plugged'. )
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There are commercial versions of this type of interface - the for example.
Of course you can connect the EM204 directly to a PIP ('Plug In Power')? input by simply attaching a 2 core screened cable to the EM204 terminals. (Core to 'HOT' -- screen to 'GND' )
The other end will need a 3.5mm stereo (TRS) jack. Both 'T' (tip) and 'R' (ring) are connected to the cable core (HOT). The 'S' (sleeve) connection is GND.
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Using the interface I've shown above is just a way of turning a 48 v phantom powered balanced input into a 'PIP' input!
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I prefer Mid/Side to X/Y. Capsule orientation is less critical - especially in a single enclosure - and you retain the ability to modify your stereo 'image' afterwards, if required...
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There's lots of options -- but mic building can become very addictive, so beware !
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