[Plextalk] Recording from Hi-Fi

Hi Everyone I know this may sound strange, but does anyone have experience of recording on the Plextalk Pocket? I am trying to record the soundtrack of a TV programme and I think the best way is to plug the Plextalk Pocket into the hi-fi amplifier and record from there (the TV is linked to the hi-fi). So far playing with the settings I have had some rather unsatisfactory results. So I would be interested to know if anyone has tried this. Thanks Pele West