Thanks for the clarification, Rod. The extent of the speed change throughout a pack is variable, but it is apparently noticeable to some--to the point where beginnings and ends of a tape could not be spliced together in some projects. I never saw this even on consumer ReVox A77 machines. I now have all constant-tension machines and in my tape restoration work I haven't actually come across a problem of any significance in this regard. Cheers, Richard