Thanks for all the responses. It's definitely not acoustic feedback - I should have mentioned that all of my listening is through headphones. I increased tracking force 1/10 gram at a time last night, and listened to music. At 1.5 grams, the breakup is gone. At that tracking force it also tracks the test tracks nearly perfectly, especially as I spent some more time adjusting anti-skate. So, is there any problem running at 1.5 grams? (although I'm not sure I want to know, as it definitely sounds best at that weight!)
Viridian- I'm using the turntable basics mirrored alignment gauge, and aligning the cartridge body square to the grid lines. To the best of my current ability, the stylus also looks square, but it's pretty hard to see. Is this what you meant?
Viridian- I'm using the turntable basics mirrored alignment gauge, and aligning the cartridge body square to the grid lines. To the best of my current ability, the stylus also looks square, but it's pretty hard to see. Is this what you meant?

