hey everyone,

EEG electrodes come with a wire and 1.5mm DIN connector. I thought it would be ok if I could remove the connector, and solder the exposed wire from the electrode to another wire and link it directly to my board..Well after trying that, I get extremely noisy signals and often the signal becomes a flatline.

Is something magical going on inside of the 1.5mm DIN connector that I was unaware of when I removed it and instead soldered the wire directly? I would like to know because I had the hardest time (impossible time) finding 1.5mm DIN adapters that didn’t involve some sort of jerry rigged solution.

 

You’ve probable defeated the shielding on your original wire by replacing it with a bit of wire. Please share pictures.

I have no experience with EEG but my guess is that it’s using balanced wires to send sensitive tiny signals and you’ve disrupted the shielding you could be turning it into an antenna for receiving stray radio signals and emi. Plus you may have affected the balanced signal that’s needed by the differential amplifiers to perform common mode rejection.