I have an late 80 or early 81 Small Stone. Whenever I first turn the pedal on the volume is a little low and after a second or two the volume goes to normal however it takes the sweep several more seconds before it starts (sometimes 5 seconds or more), after the pedals starts working it continues to work without problem until it is powered off for a while. I have already replaced the electrolytic caps with no change. I am thinking that possibly one or more of the mylar caps could be bad. Any help would be appreciated.