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I hope, soon, to build a new plinth for a Lenco idler drive turntable I've just purchased, and noticed that many people strive for a heavy, dense plinth to handle the power of these idler drive motors. Plinths weighing in the order of 75-100 lbs. are claimed to be superior to lesser weighted options.
I will be placing my turntable on the heavy, black walnut butcher block shelf of my equipment rack, so I was wondering if I could aim at a less heavy plinth and obtain similar results. That is, would coupling - using spikes - a 50 lb. (for example) plinth to a 25 lb. dense wood shelf be as effective in damping motor vibrations as creating a 75 lb. plinth?
This might sound silly, but what about an actual butcher block table!! I have seen them occasionally and the tops are a bit beat up. But if you sand them down evenly and make the appropriate cutouts.............hmmmm
Not silly at all. I've been using such blocks as a TT base for years. Currently I'm using a slate block for the TT and the butcher's blocks are under the rear speaker stands!! No cutting necessary for my Notts Hyperspace/Teres Verus system but it still needs support.
The short answer: It depends.
I have built turntables from both viewpoints, and how they sound depends on your objective. A Lenco, specifically, can sound great without a tremendous amount of mass. I built one that is comprised of two parts, the top being tuned for the resulting sound, and the bottom for isolation. The sections weigh thirty-five pounds each, and fit a typical turntable's footprint.
The result was a very clean, but ever so slightly warmish sound. It's musical enough to listen to daily, so I know the idea has merit. You would have to spend several thousand dollars to beat such a DIY project.
There are a lot of ways to skin the turntable cat, so proceed with an open mind.
I had the same objective as you a few years ago. Where I began was to research plinth design considerations noted by highend table makers. What I learned is that you cannot stop resonance transmission, only tune and filter it.
My Lenco table uses two MDF center sections then alternate birch ply and MDF layers, resulting in a total weight of about 50 lbs. I think there are still pics at LencoHeaven but I have not visited there for some time.
In my opinion the best material is slate. I even bought a block of cemetery headstone material to make a plinth. The problem I found is that cutting it really requires a CAM/CAD system. The expense was way beyond my budget. Even the custom slate plinths for Lenco are beyond my budget.
I must say that building my plinth was a labor of love. I surrounded the plinth block with half inch thick birdseye maple. Oh, and the result of my efforts has exceeded my wildest expectations. The plinth coupled with the Lenco table and Alphason tonearm (w/ ZYX cartridge) can really make music!
"Always Searching for Perfection"
I have to disagree with the above comment about cutting slate,if you look on LencoHeaven plenty of people have cut plinths using angle grinders or even ceramic saws.
Drilling holes is also pretty easy in slate. In general if you make a mistake you can always refill the hole with adhesive mixed with powedered slate and when its hardened just have another go.
There's also good arguments about using some of the new super adhesives and just glueing the tonearm or plinth directly to the slate plinth.
In my experince so far I have built a multi layered plywood plinth and it was probably harder work than making a slate plinth.
Your definition of "pretty easy" must be way different from mine.
In pursuit of drilling holes in my slate plinths, I tried many different types of bits, since one cannot go into a hardware store and ask for a bit made to drill slate. (Or, one can ask, if one does not mind a look of consternation from a salesman.) After spending a fair amount of money on bits that looked good for the job and proved worthless, I did finally identify one particular company whose bits seem to work "fine". (I can get the name for anyone here who is interested. I think it's ATR.) But even then it requires the patience of Job as you wait for the drill to make headway in the slate. Plus the dust created is pretty awful; do it outside or in your garage. Plus the hole is very apt to be wider in diameter than what you intended, due to crumbling of the slate at the edges of where the bit is working. Allow for that.
Yes, I too have seen on Lenco Heaven that several guys have managed also to cut slate with various tools. Here's what I did; I first ordered my slabs to be honed on both sides so as to create plane parallel and completely flat surfaces. Then I had the slate cut by a water-jet company. IMO, that's the only way to get perfect (or near-perfect) results. Of course, to do that you need either to have a pdf file to program the water-jet or to create one to suit your needs. I found a really good programmer who could work with me to create the necessary files. The water jet work cost no more than a few hundred dollars per plinth and was well worth it.
I don't know if this will work on slate - it does on marble. Just build a plasticine dam around the area where the hole will be drilled and fill it with water
Your idea kind of recapitulates the method of the water-jet.
My idea is that, after having "made" four slate plinths (for Lenco, SP10 Mk2, SP10 Mk3, and Denon DP80), never to do it again. I thoroughly scratched that itch.
I completely agree. A water-jet is the right tool for the job. If you can program your design to direct it that's even better.
Unfortunately, I just did not have the resources to go this route. But as Mosin indicates there are many ways to get the sound you want through design materials and parameters.
I am very happy with what I determined was best for my situation. And I enjoyed the path to get there.
"Always Searching for Perfection"
I don't disagree with what the other fellow said, but I would just add that the nature of the build materials matters greatly, as well. In other words, I can imagine a 50-lb plinth that would result in better sound than a 100-lb plinth, if the materials used to build the former were superior to those used to build the latter. In my limited experience, hard woods and slate trump MDF and the like. Granite and marble are not at the top of my list, either. But as you may know, some folks mix a layer or two of MDF in with layers baltic birch plywood, nothing exotic, and can get good results. Lenco Heaven is one place to start.
IMO - no such thing as too much mass anywhere (the plinth, the stand, the platter, the motor housing, the bearing cap, etc.). If you can make both a massive plinth and stand then that's the way I would go.
A gentleman is best defined as someone who knows how to play the accordion ... and doesn't.
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