[Hartley118]

Back in the day when 78s were the norm, we were advised to 'listen through' the surface noise to hear the full frequency range of the music. The brain is pretty good at intelligent filtering and learns to ignore unwanted steady background noise. I've always found this approach preferable to serious treble roll-off, though it's sensible to use a steep-cut low-pass filter to limit the reproduced frequency range to that recorded on the disc, i.e. 6kHz for early electric, and around 8kHz for post-1930 discs. Ideally, with Decca post-war FFRR one could open the 'window' to 15kHz, but I find that often their pressing material is so poor that surface noise is then too prominent. It wasn't till the 1950s that 78 surface noise reduced to the level achieved in the 1920s by Columbia with their 'New Process' laminated pressings.

As already mentioned, transcriptions of 78s on to LP discs and CDs can so often be disappointing because of excessive treble roll-off: I personally prefer to listen to the full range 'through the noise'.

Cedar and similar intelligent filters can give remarkable results by doing their own 'listening through the noise'. Whilst Cedar keep much of their technology close to their chest, AFAIK their processor identifies the 'signature' of the noise and subtracts that from the noisy signal, leaving relatively clean music.

Martin