Dust covers

+1, cover off.

not improvement, it is about avoiding the potential detriment of reflected microphonics if the dust cover is closed while playing.

if you don't hear any detriment ....

I always remove mine because the vibrations in the cover impacts overall sound quality

The plinth should be free from all vibrations, so having a lid that can vibrate in sympathy to the music is causing those vibrations to be transferred

• into the plinth, down the arm and into the cartridge
• or into the plinth, through the main bearing and into the cartridge
• either way - it’s not desired

It’s easy to determine...

• get a stethascope
• place it on the lid while playing music
• if you hear virations - those are then getting into your signal via rhe plinth/arm/cartridge

You can also checkout if the plinth is vibrating using the Stethascope also

Regards - Steve

@shiner3237 , If the dust cover is attached directly to the platform the plater and tonearm are attached too then it can be a problem open or closed. However on suspended turntables where the platter and tonearm arm are attached to a sub chassis that is suspended within the plinth and the dust cover is hinged to the plinth isolated from the plater and tonearm, dustcovers are a huge advantage. They protect the record and tonearm from dust and attenuate the sound getting to the cartridge by 10 dB and since they are isolated from the plater they can not pass on any resonance. They are hearing protection for your cartridge! Turntables that are designed like this include some Thorens designs the Linn LP 12 and the Sota turntables. People who do not use a dustcover during play are grinding incidental dust into their records. You you have a turntable that is not suspended and isolated and can not use a dust cover during play the solution is to get an isolation platform and have a dust cover made to fit around it. 

IMHO if you can not use a dust cover it is because your turntable is poorly designed. (that should raise some eyebrows:-)

@mijostyn , 

Yet aren't you the person who doesn't see the need to clean new lps?