I use the VPI ring clamp with my Classic 3. It does seem to help flatten out slightly warped records but honestly I don't hear much of a difference with it. It's also a PITA to get installed correctly on some records as it can slip off an edge. I'm not sure if it's due to variations in record diameter, record thickness, or possibly slightly off-center drilling but whatever the cause the outer ring can wobble slightly if it's not sitting perfectly. That can't be good...so is the cure worse than the original symptom?