What recording system are you using? I record programmes for Radio Britfolk directly into a PC via an analogue mixer (Soundcraft 400B - a bit elderly, but works well!), and have no problems with background noise.

Noise problems can arise from the ambience in the room. I used cheap internal doors covered in carpet to deaden the ambience of my studio. Poor quality microphone pre-amps can hiss, too.

You should be able to get a 'clean' recording without resorting to signal processors, then do a little normalising/compression with software afterwards.