Mono records are mono. Playing them back in stereo introduces artifacts which are noise and distortion and is just a further burden on any noise or click removing algorithm. If you sum the channels you will have two identical channels. Any clean-up algorithm will not "know" that they are not different from each other.
The summing is best done as soon in the chain as possible to get the best possible gain and phase match.
I have many 78 RPM records which I listen to in real time with no clean-up algorithm other than the proper EQ and some of them can sound very good.
tinpanalley wrote:The thing is that by making it mono right away you remove the possibility of cleaning it more thoroughly first. It's my understanding that all recordings from vinyl or shellac, be they mono or stereo are best captured in stereo for more accurate cleanup.
Is this wrong?