Audio problems with DVD recorder

More problems with my new DVD recorder. I recorded a show from TV. When I recorded the show, the sounds was turned down. Somehow I don’t think that matters, I think some other setting is messed up. When I try to play it, the sound is very very low. I am sure I have something either not set, or set incorrectly. Any idea why I cannot hear my show?

Ok, now I am really confused. I turned the DVD recorder off and on, put the same disc back in and it played with perfect sound. I did some experimenting. I set the input to Line 1 as the manual suggested and nothing at all recorded. I then set it to Channel 3. On channel three it records just fine either on the standard TV setting or Aux Line 1, and plays back only on line 1. Further, with the DVD turned on I receive TV stations on both chanel 3 and Aux Line 1. With the DVD turned off, I only receive TV on channel 3. What I would like to do is have it work like my old unit, where I could record and play on Channel three, and never had to go to Aux at all. Is that possible? Right now the recorder is connected to the TV two ways, via cable out and via three RCA plugs for sound and video. If I disconnect the RCA plugs and keep the cable video out from recorder to TV will I then be able to do this. I know I am rambling, but I find this all very confusing. Any help at all would be appreciated.