I am trying to record on a Tascam DP O2 with acoustic guitar in input a and microphone in input B. I am monitoring through headphones. Headphones work for demo songs and songs loaded to the system by other people. When I am choosing effects for my recording, only an electric guitar effect can be heard through the Headphones. No other effect can be heard, such as vocal which is what I want on the microphone or any other option. I understand the effects only apply to one input which is fine. I only need effects on the microphone. Please help