[codefox1]

Please post schematic or link here. something does not sound right to me. Candohm is usually used as a voltage divider and rarely terminates in B- or ground in 3rd tap of a four tap unit if that i's what you have. Not unheard of, but let's have a look. Associated capacitors etc... will tell us what is right. Maybe perfectly OK and third hook is B-, and there might be bias supply, well, hard to do this blind.