Originally Posted by vanKloot
My actual application here is recording 78rpm records at 33.33 rpm and then speeding them up to correct pitch/speed. Audacity does this perfectly fine, this was mostly an exercise in "I wonder if I can do this directly in Reason?" Basically looking to increase my Reason skills & knowledge by trying something I wouldn't normally do in it, to stretch my thinking.
It's worth pointing out that what Audacity is probably doing is simply speeding up or slowing down playback (and then resampling the result) in order to get the pitch and time adjusted. But that doesn't work like that in the Audio Tracks in Reason. Pitch shifting (or time stretching) by itself is a somewhat more complex operation, as it has to be able to adjust one parameter without affecting the other.
I'd love it if Reason could introduce a simple playback-rate setting to its audio clips, but I'm the only one I know of who ever asked for it in the Feature Suggestions forum. (Will Reason 7 have it? I dunno. Not holding my breath.)
The point is, you're introducing quite a bit more processing of the original audio, leading to more potential deviation from the original signal (and if you're recording 78 rpm records at 33, you're already hip-deep in signal deviation).
For fidelity's sake then, your best option would be to use a sampler, which would just slow down or speed up the audio playback. The problem is, you'd have to somehow calculate the exact ratio from the 33 and 78 speeds and turn those into semitones (and probably do some fine-tuning in cents) to find the exact settings to achieve your speed change. But once you had that, it would simply be a matter of plugging in the same settings for each audio file you wanted to convert.