A two-piece screw clamp (as Markd51 described and as Teres clamps are) makes it easy to avoid label damage. Just stop the clamping piece from spinning while you tighten. One-piece screw clamps don't allow that, so *may* risk some label damage.
If a clamp uses rubber or a similar material at the interface between clamp and LP it may have a negative impact on sonics. Rubber absorbs vibrational energies, shifts them in amplitude and frequency, then releases them after a time delay. This softens transients, dulls dynamics and smothers low level details. In a word: mud.
If you can, try removing the rubber bit and using the clamp "bareback". Your system resolution will probably increase. Everything should tighten up a little. If maximum resolution is your goal, remove rubber from around your analog rig wherever you can.
If a clamp uses rubber or a similar material at the interface between clamp and LP it may have a negative impact on sonics. Rubber absorbs vibrational energies, shifts them in amplitude and frequency, then releases them after a time delay. This softens transients, dulls dynamics and smothers low level details. In a word: mud.
If you can, try removing the rubber bit and using the clamp "bareback". Your system resolution will probably increase. Everything should tighten up a little. If maximum resolution is your goal, remove rubber from around your analog rig wherever you can.