I've been using an EP-3 for a couple of years now and it's been sounding great. It was in pretty good condition when I got it. But recently, the repeats have started to become very warbly and out of tune sounding which I don't like at all as I mainly use it for slap back echo. I have a new tape on the way but was wondering if it may be the rubber roller needs replacing or something else? Does anyone have any experience with this sort of thing?