Does anyone know a program or plug-in to make a nice, clean modern recording sound like a late 40s-50s record (also played back on old equipment)? I'm trying to make one for a music-theatre piece I'm working on.

So far I've managed to get a little pitch-wobble (or 'wow' - but I can't specify the frequency exactly) and some old-fashioned reverb (not sure how authentic) and filtering. So what I really need now is the surface noise and crackle of an old, worn record (ideally at 45rpm I think). Of course I have plenty of records that sound like that, but they all have other music on them 

Anyone got any ideas?

 Your 45s must have a run-out groove, Stuart: I'd record a selection of them and then create waves of 1.333 seconds or multiples thereof: normalise them and splice them digitally together in random groups until you have enough to run past the length you need. That will give you the right surface noise with the correct cyclical pattern.

Open a new file with 4 tracks (or 2 if you're working in mono): the new music is assigned to tracks 1 and 2 (or 1) the surface noise to tracks 3 and 4 (or 2). Allow a lead-in before the music, to set the 'atmosphere', then play around until you get the right balance, before mixing down. You'd probably be advised to filter the music track, too, so that it has the right sonic signature: a mid-range boost, with high and low filters 'in' would get close: restricting its dynamic range, would probably help, too.

Stuart, the plugin you want is probably this one, Izotope Vinyl - you can tweak things like amount of wear on the record, dust, scratches and so on. It's free and comes in all reasonable formats.

Thanks Richard - that's a lovely little program! Should do the trick.