The Riggle VTAF works but you have to take care when you adjust it during playback. The VPI Prime is a better implementation and seems to be impervious to any bad side effects when you adjust VTA. Nonetheless you always take care.
Most of the time I adjust the VTA just prior to spinning the LP. The advantage is I am familiar with my library and know which LPs sound best at which settings. I am somewhat anal about my LPs and I keep a maintenance log with each LP and some of them have notations for VTA settings.
For the ones that do not have VTA info, I adjust the VTA based on the weight of the vinyl.
Ed
We don't shush around here!
Life is analog...digital is just samples thereof
