Scrappersa
Well-known member
- Joined
- Jul 17, 2011
- Messages
- 150
I'm having a bit of an odd issue that I was hoping somebody might be able to help out with.
I have a home-brewed KM84 board that seems to be getting continuity on the XLR between pins 2 and 3- but only when the transformer is soldered into the PCB. I have a few Cinemag 5:1 and 7:1 transformers that I've tried in the circuit and they all behave the same way. The XLR is an Amphenol that's soldered directly to the PCB. I have three drastic revisions to this board and they all do the same thing.
The Cinemag transformer leads do not have continuity on their own. The XLR pins do not have continuity without the transformer soldered in. If I desolder a single lead (any lead) from the PCB, the continuity disappears.
When the transformer is soldered to the PCB, XLR pins 2 and 3 have continuity.
I'm wondering if I've missed something in the schematic that is causing this. My understanding is that with pin 2 and 3 continuity, the microphone is unbalanced so I'm losing about 6dB of output.
I have a home-brewed KM84 board that seems to be getting continuity on the XLR between pins 2 and 3- but only when the transformer is soldered into the PCB. I have a few Cinemag 5:1 and 7:1 transformers that I've tried in the circuit and they all behave the same way. The XLR is an Amphenol that's soldered directly to the PCB. I have three drastic revisions to this board and they all do the same thing.
The Cinemag transformer leads do not have continuity on their own. The XLR pins do not have continuity without the transformer soldered in. If I desolder a single lead (any lead) from the PCB, the continuity disappears.
When the transformer is soldered to the PCB, XLR pins 2 and 3 have continuity.
I'm wondering if I've missed something in the schematic that is causing this. My understanding is that with pin 2 and 3 continuity, the microphone is unbalanced so I'm losing about 6dB of output.