dodecahedron wrote:i wonder what the difference between the 2 'technologies' are.
VAS:
Name: Isolated Absorber System
Slogan: VAS
Similar design: Pioneer
Advantage: Small vibration on Traverse / Pickup & Cover
Dis-advantage: Space limitation, hard to design the isolated absorber
ABS:
Name: Auto Balancer Spindle
Slogan: ABS
Similar design: LG, Samsung
Advantage: Lowest vibration in high rotation speed
Dis-advantage: Sacrifice balance disc, hard to design, different design result different
(Found
here along with diagrams for several other suspension designs)
It is hard to see in the small diagram above, but ABS also has a series of ball bearings that are designed to distribute themselves to balance the disc:

Steel balls as balancer within spindle motor will be settled into right positions during spin up period ( that’s the reason why a lttle noise during drive spin up to read a disc ) to compensate imbalance of the disc when rotating at very high speed.
I have an old 166S with ABS. The ball bearings make an odd "whiiiish" sound when the drive spins up on load and down on unload.
cfitz