For the first 15 years I owned my WTT Reference turntable, I just played records and was happy. When I moved a couple years ago, I learned the suspension of my cartridge was shot, so I had a dealer install a new Lyra Delos cartridge. It was a year or so before I got my system set up in the new place, however, and when I checked the VTF it was at 2.2g. Thinking the dealer had his head somewhere dark and stinky, I reset it to the recommended 1.72g. I checked it the next day and it was at 1.4g. I fiddled around with different ways to make the digital scale exactly the right height, and I got good repeatability--within +0.1g. I finally decided I'd just check it every playing session and adjust as necessary.
When I first set up the 'table at the new place I had the cup screwed all the way down (minimum damping). Yesterday I raised the cup two full turns (about 1/8"), thinking that my problem was that the paddle would sometimes be submerged and other times rest on top of the solution causing the big swings in VTF. The paddle is now submerged, but I still saw VTF vary from 1.4g to 1.8g.
Does anyone else have this issue? The Lyra cartridges are very sensitive to VTF (and VTA), so unless I can get things it doesn't make sense to use such a good cartridge on this tonearm.