Reading through other posts:
https://www.sundance-communications.com/cgi-bin/ultimatebb.cgi?/ubb/get_topic/f/13/t/000488/p/1.html it sounds like maybe I'll need to put in a 1000uf electrolytic filtering capacitor; I suppose across AB and AG (I say I suppose because I'm wondering if it should actually go across Tip and Ring).
I think the hum is caused by the fact I'm using the AB for both AB and BB. When using my old intercom card, there was no hum, so I don't think there is necessarily anything wrong with the power supply.
I'm thinking of going up to radio shack tomorrow to look for such a cap. I'm guessing it will need to be 24v or the next higher value available.
Thoughts?
Thx
Matt
