ISOLATION PLATFORM

CD STABILISER

DAMPING

Highly effective
Practically free
Lots of opportunities for experimentation

As you know, any platform used for supporting Hi-Fi and AV equipment needs to be stable, inert (resonant free) and level. We've all seen the many solutions put forward in an effort to meet these criteria- heavy materials, light materials, thick materials, thin materials and even clamping equipment in mid-air within a frame. All these methods work to a lesser or greater extent and can be used to fine tune or tonally re-balance a system. An interesting project which meets all the above criteria, is tunable and costs pennies to put in place is outlined below.

The platform is based upon the energy absorbtion characteristics exhibited by a gas under pressure- pneumatics.

You will need to obtain a quantity of, large bubble, bubble wrap (9.53mm H X 25.4mm W), sandwiching a double thickness between two pieces of either thick glass (10mm minimum) or Medite (MDF) with cones placed on the top and the bottom. Experience shows that the air eventually leaks from the bubble wrap and so you will periodically have to replace it- the heavier the equipment, the more often you will need to do so. The fine tuning comes in to play because if you use glass for the platform it will result in a more forward presentation than if Medite were chosen. It is worth trying both, or even a combination, to get the correct balance.

Alternatively, use tennis balls cut in half- they aren t quite as effective but are useful for heavier equipment.

The result of this minor piece of inexpensive DIY will be, more detailed and dynamic presentation which will not harden or become confused on transients. The CAD Air Sandwich.

Highly effective
Very low cost
Fit and forget

Not surprisingly, as a compact disc spins it is subject to vibration and vertical movement. This movement prevents the accurate retreval of information and hence affects the overall performance of the system. There are a number of (mostly expensive) pads that can be fixed to discs to dampen this movement. As the problem is a simple one, we wondered if there was a more affordable (cheap) solution. We needed to find a readily available and inexpensive material with good damping characteristics and low mass.

We came up with cork.

It is advisable to use the thinnest cork sheet you can find, for two reasons,
1). You do not want to add undue mass to the disc as this could de-focus the laser
2). Too thick a layer may prevent the disc from spinning in certain transports

Armed with your thin cork sheet (less than 1mm is ideal) simply cut it to the size of a CD and attach. You should also make sure that a 2.5mm (1 inch) hole is left for the central clamping mechanism.

There are two things you should bare in mind:
1). If you use self adhesive cork it may be difficult to remove it once it is fitted
2). You must ensure that the cork is accurately and evenly placed on the disc, otherwise you just may make things worse!

Highly effective
Inexpensive
Fit and forget

Mechanical resonance is a big problem in Hi-Fi systems- adding mass never makes things worse. Damp everything, but what with?

For small scale damping there surely can't be anything more effective than BluTak.

Use it on anything that needs "mass". I particulary like adding it to the drive assembly of inexpensive CD players. Be careful and only add a small piece at a time but it really works. It will damp out resonance on anything from a CD player to a loudspeaker. One word of warning- we can't be held responsible for any damage to your equipment.