I agree that the first thing you should try to ascertain is the pumping caused by airborne or mechanical anomalies. So ...
- move the speakers
- put up some kind of baffle between the TT and the speakers
- move the TT off the rack onto the floor or in another room
- check and double check your cartridge alignment
- try a different counterweight and play with location (heavier weight closer to the pivot point, or lighter counterweight placed farther from the pivot point)
- try a record clamp or periphery ring (if you can) to see if you can get a better interface between the vinyl and your platter surface
If that doesn't work then check your cartridge compliance and theoretical resonant frequency. Add something to the headshell to increase the mass of your tonearm (rebalance and reset it all, of course) and see if that alleviates anything.
In my case it was definitely caused by the arm-cartridge compliance. Switching cartridges removed the problem entirely.
Good luck,
Bob
- move the speakers
- put up some kind of baffle between the TT and the speakers
- move the TT off the rack onto the floor or in another room
- check and double check your cartridge alignment
- try a different counterweight and play with location (heavier weight closer to the pivot point, or lighter counterweight placed farther from the pivot point)
- try a record clamp or periphery ring (if you can) to see if you can get a better interface between the vinyl and your platter surface
If that doesn't work then check your cartridge compliance and theoretical resonant frequency. Add something to the headshell to increase the mass of your tonearm (rebalance and reset it all, of course) and see if that alleviates anything.
In my case it was definitely caused by the arm-cartridge compliance. Switching cartridges removed the problem entirely.
Good luck,
Bob