JS-8, E-BAND: Time Shifting and Audio Quality
Time-shifting requires very intensive realtime calculations, and the JS-8's brain has to crunch thousands of numbers per second on-the-fly when the tempo is changed. Depending on the complexity of a phrase's audio, the sound quality of the time-shifted result will vary, with the best results being achieved with less complex material.
Another factor is how far the audio is time-shifted from its original tempo, with better quality the less it's shifted. Keep these considerations in mind to achieve the best results when time shifting.