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RFI with Phantom Power: Bellari RP503

Posted: Mon Mar 26, 2018 4:36 pm
by Bow
Howdy gents, long time since I've posted here... but I have an interesting one...

I did the hacking of the circuit board to separate the Pin 1 from the circuit board ground when I picked it up back in 2008...

I have noticed I'm getting RFI when using Phantom Power... I haven't disconnected the Mic cable from the Preamp yet and try it, but with the mic disconnected, it is still doing it...

My RP503 is getting up in age (I've had it around 10 years), I'm wondering if I am losing a filter cap in the Phantom Power Supply?


Anyone else seen something like this?

Posted: Tue Mar 27, 2018 1:13 pm
by Bow
Well, It seems it isn't the Bellari after all... it is the MXL 2008 mic...

Image

The is the Mic Element negative signal ohm'd out to Pin 1 on the XLR connector...

Muthaf$#%'n MXL mics obviously don't pay attention to the Pin 1 rule... the Shield pin goes to the Case, NOT the Circuit Board Ground! :shock: