I use talc on my VPI round belts after a cleaning in soapy water, rinse, dry. It does sound better.
On my flat OL belts, I just clean them as above. Performs better without talc.
Turntable Belt Care—talc or corn starch?
While servicing my belt driven turntable recently I discovered my 15 year old container of unscented talcum powder had disappeared. While shopping for more, I found that drug store talcum powder isn’t really talcum powder anymore. Because of cancer concerns, the talc has been replaced with corn starch. For our needs, both can be considered a lubricant.
VPI said using corn starch on the belt is okay, just make sure to wipe any grease off of the belt, pulley and platter rim before you powder and install the belt.
In the past some manufacturers put talc in the bag with the belt. Anthrax fears ended that.
I was able to find real talcum powder online and some dive/surf shops have it (to ease donning wetsuits).
If you’ve forgotten how to powder the belt, put some powder in a baggie with the belt and shake, take the belt out, shake off the excess powder and reinstall.
Why do this? The powder allows the belt to slip slightly on start-up acting like a clutch, reducing/eliminating belt noise and extending belt life.
Maybe it’s just me, but I prefer using talc (a mineral) over cornstarch (a food). Perhaps it’s that talc isn’t water soluble so it’s unaffected by humidity or moisture like corn starch? Is that really a concern? Or that manufacturers have recommended using talc in the past and not the more common corn starch?
Either way, now you’re aware. If even you care.
And if you have a direct, magnetic or idler arm turntable, no belt, no worries—you can stay out of your wife’s kitchen domain looking for corn starch. I recommend that like I recommend talc.