A rather more fundamental change than I have anticipated...

[maxg]

As many of you know I have a Project RPM 4 TT that has been upgraded into insanity.

The penultimate upgrade was to the feet. I finally got around to switching out the little standard rubber feet for some cones and have noticed some improvement in the sound.

Thinking about it, however, I realize that this is actually a very dramatic change to have made. The old feet were spongy and acted as suspension for the TT. The new feet are totally solid.

In other words I have just lept from a suspended table to a high mass table - but without the necessary mass to pull it off completely.

Over the last week or so I have being doing a series of little tests amde easier by the fact that Tony has bought himself a used Systemdeck 2 TT with a pair of platters.

As that TT came sans arm he lent me the 2 platters to play with on my Project.

One of the platters is come kind of acrylic - in black, the other glass. Whilst the acryllic is thicker is it lighter. Neither are the height of the existing platter - so changing should have involved several arm height adjustments.

The first thing I noticed about the 2 visiting platters is that, together, they are exactly the same height as the original. Therefore this was my first port of call. Place the Acryllic on the bottom and the glass on the top - test - then reverse the order and re-test.

Logically the glass on the bottom should have been better - if there was any difference at all. It wasnt. Despite having the higher density, and mass, it worked better on top - no idea why.

There was simply no comparison to the original platter - it was much clearer, cleaner and more defined in all areas.

The problem is that I cannot keep both platters - Tony wants the acryllic. With this in mind a rigged up a support for the glass platter atop an "O" ring of rubber (actually a dog chew) and have been playing the table this way for the last 4 days.

The sound is good - much better than with the original, but not as clean as it was with the 2 platters combined.

I was pleasantly surprised to find that the glass doesnt "ring" as I had half suspected it to. It is surprizingly inert sonically.

So where to from here?

Well - I realise that I need mass - and lots of it (I also need to be careful with the motor - it wasnt designed for the mass I now have in mind - but as long as I manually start the thing turning it doesnt seem to be a problem).

3 choices and one option:

I could get a piece of glass made to the thickness of the original platter (about an inch) if I can find someone able to do it accurately enough.

I could forget glass and go with marble.

I could hunt the net for aftermarket high density platters.

Further, whilst upgrading the platter - I may as well look at replacing the body of the unit (MDF). Again Marble springs to mind - the shape does not look all that complex - as long as the stone mason can accurately position the wholes it should be fine.

That is as long as the bearings in the sub-platter assembly hold up..

Alternatively I could just buy a Clearaudio, Acoustic Solid or a VPI and have done with it - but where is the fun in that???

[marksdad]

max i enjoy reading about your trials with your pro-ject tt, i keep watching because i also own one and soon i just might start following your lead and attempting tweaks

[maxg]

MD,

Dont do it - honestly.

Just sell the thing and buy a decent TT in the first place. This has cost me God knows how much - definitely more than the Clearaudio Champion / VPI Scout options.

I am now beyond the point where sonics are the only driving factor. Every day my system gets to be a little more home made. That gives me almost as much pleasure as listening - but it is not the cheap option!!!

Of course if you want to go this route - feel free - but dont say you weren't warned!!!!