Piano with vibrato - ouch!
That should not happen with a Shelter 901 on either of these arms.
1) Does this occur on only a few records? If so, are they drilled off-center? That will produce pitch-warbling every time. The only fix is to replace them or widen the spindle holes so you can center them before clamping.
2) If the records are drilled on-center it's probably the cartridge. Try another cartridge (any cartridge) and see if the problem repeats.
QC = Quality Control: methods used to ensure that every manufactured item or business process meets specifications, within defined tolerance limits. (I don't know the equivalent term in French, but it explains why one Exocet will hit the right house while ten Scuds can't even hit the right city!)
That should not happen with a Shelter 901 on either of these arms.
1) Does this occur on only a few records? If so, are they drilled off-center? That will produce pitch-warbling every time. The only fix is to replace them or widen the spindle holes so you can center them before clamping.
2) If the records are drilled on-center it's probably the cartridge. Try another cartridge (any cartridge) and see if the problem repeats.
QC = Quality Control: methods used to ensure that every manufactured item or business process meets specifications, within defined tolerance limits. (I don't know the equivalent term in French, but it explains why one Exocet will hit the right house while ten Scuds can't even hit the right city!)