MDF or Plywood for best sound in Hi-Fi rack ?


I need to make to more shelves for my rack. One for my CD and one for the preamp. I use Vibrapods under each unit. Is MDF or plywood better for sound quality or vibration control? Thanks
frano
hmmmm.....? I have all my gear on a low cost metal shelf rack and each shelf has a grate...like the racks in the oven. The cd player is on a few sheets of foam..the no skid stuff that comes in rolls and is used to line cabinents. How critical is it to get this gear on a more dense board? The turntable is on a hard board.
I would go for plywood !! Look here: [http://www.6moons.com/industryfeatures/livingvoice/definitive.html]
Maple butcher blocks are quite a bit better than both MDF and plywood. Have a look at this thread - http://forum.audiogon.com/cgi-bin/fr.pl?htech&1158841915&read&3&4&

I sourced my butcher blocks form Tony’s Woodshop in PA. He was quite a bit cheaper than all the other suppliers I tried.

Regards
Paul

BTW, I am not affiliated with Tony in any way.
In my view the jury is still out on Maple butcherblock vs plywood, for the simple reason that I have not yet seen the results of any in depth experimentation with high quality plywood. There are some very interesting plywoods out there. For example, Finnish company UPM-Kymmene makes an extremely high grade Finnish Birch (not generic Baltic) product. The mechanically most stable type is the one rated for exterior, which can be recognize by the presence of thin black lines of glue between the layers of veneer. The thickest sheets normally imported in the US are 1 and 1/8 inch thick, but 2 inch thick sheets can be potentially sourced from the manufacturer in Finland. Blocks of the material are so stable that they can be precision machined and carved for prototyping of mechanical parts by tool&Die designers. I have experimentally worked on some samples. Progressive power sanding down to approx 3200 grit yields a highly polished seemless surface both on face and edge.

If I recall correctly, a 4ft x 8ft sheet of the max thickness costs $120. Such a sheet is made from 20 layers of extremely hard Finnish Birch veneer. Conversely, the same thickness sheets classified as Baltic Birch is made from approx 12 layers.

Constructing shelves or platforms by gluing 2 or three layers of such UPM Finnish material is likely to yield an amazingly stable surface, likely devoid of resonance at audible frequencies. Whether such a shelf is inferior or superior to a similarly thick maple butcherblock unit has of course to be demonstrated. It is worth pointing out that one of the reasons that Maple is used in platforms and shelvings is the romantic notion of its inherent musicality, as it is almost universally the choice material from which the solid wood back of the best violins, violas and cellos are constructed. However, in a musical instrument, the back is part of a mechanical sound amplifier, in which the wood needs to vibrate to generate music. Not so in our isolation platforms, which we want largely to sound as dead as doornails.

UPM Finnish plywood can be sourced in the US from

Plywood & Doors
866. 738. 7265
Speak to Rod.

Please note that minimum order is $300, which means 3 sheets. From three sheets you can build a sizeable number of shelves and platforms.