Mass and vibration cancelling on top of CD player?

The VPI brick is an electromagnetic device. Roxy54, I have a sneaking suspicion Rja was pulling your leg.

Making the chassis rigid doesn't prevent the disc from vibrating, which in and if itself is not too good for the sound. One way to ameliorate disc vibration and flutter is to obtain absolute level of the disc while spinning. Not as easy as it sounds.

Roxy54, you cannot ensure that the disc is spinning level by checking the level if the chassis. Just saying.

Generally speaking then, the level should be placed directly on the spindle or another place on the transport compartment that is the same level as the spinning CD. Using the top of the CD player chassis or even the CD tray is unreliable. Unfortunately, unless the player is a top loader the cover of the player must be removed to gain access to the transport compartment. The reason level is critical is that a spinning CD will flutter more if not level, especially when out if round as many are.

Maybe so, Roxy54. I'm speaking generally. The laser is suspended on springs, so level could be an issue for the Pioneer. Only one way to find out.

I dunno, Roxy54. How could just about anything be unreliable with servo control and Reed a Solomon error correction? Lol

What I meant was, in a sarcastic way of speaking, that most people would probably be inclined to say that level of the transport/disc is not critical since any unnecessary motion of the disc due to its non level condition during play or any other reason is accounted for by the servo mechanism that controls the laser when it gets off the nanoscale spiral data track. And, of course, Reed Solomon Error Correction Codes are supposedly going to correct any errors that occur anyway.

It should be pointed out that structureborne vibrations, the ones coming up from the floor, produced by Earth crust motion, traffic, etc., are quite debilitating on the sound and need to be dealt with in some fashion or another. The spring mounted laser assembly is not impervious to very low frequency structureborne vibration in the range 0 to 8 Hz.