Actually, there are some signs similar to latin [r]. these are [ռ], [ր], [ղ].. but all those are considered different letters. I was talking about [ր], which sounds the same in every way – softer. I can write you transcriptions for those letters, but I don't think that's going to make any sense. I pronounce them to Skype to my students for several hangouts..this is how they get the difference of so many similar sounds in Armenian. Good luck!