Avtech 4 channel DVR with 1 channel audio input

[NB2A 0]

I bought this about a year ago from a vendor Supercircuits that has no idea how to get the audio function to work. I am getting audio out from the rear jack so I know the camera I am using has audio going into the DVR.

 

I cannot seem to get any audio from a recording or via the network.

 

Is there a way to test the audio with any software?

 

Thanks for any advice

 

Tom