Building high-end 'tables cheap at Home Despot II

Hi Kravi4ka,

Does your modified Rega 250 have any added VTA adjustments or is it stock & static?
If your Rega is in the original fixed version with only washers for height adjustments, then you’ll probably want your armboard about 1/8” below flush of the top plinth layer. I say “probably”, because I have a mounted Rega 300 and I’m assuming that the pillar/tube height mounting geometry is the same on the 250.
With mine mounted flush to the plinth without washer, the tube is horizontal with a generic height AT mm cartridge. But I don’t think this is optimal, because someone once wrote here many moons ago, (think it was Willbewill) that a Rega engineer said that these arms are optimal with their butts dragging a bit. But many things can throw minute variances into the VTA formula – cart height, platter mat thickness, the number of bearing thrust shims, MuMetal treatment, etc. Then there’s the question whether you’ll use something to isolate the armboard from the plinth or not. Some use plastic washers, others use rubber grommets and still others directly mount.

But my advise would be to plan for VTA and armboards, but don’t sweat it too much. By making multiple armboards of various thickness and flavors of wood (this stuff is freebie scrap at most lumber yards) you’ll give yourself room to experiment. The only hardwood I’ve heard spoken about negatively for this application is oak. Linn armboards are plywood – probably nicely laminated – but plywood nevertheless.

Maybe Stefanl who has helped me out with Rega issues will weigh in here.

All best,
Mario

Has anyone made a plinth with alternating layers of MDF and
Solid maple? Results? What difference is there with this and birch ply?
Thanks Tessera

Congratulations on scoring some Lencos, a Rega tonearm AND a Denon DL-103 Kravi4ka, a KILLER set-up for little money, killer enough to slay high-end belt-drives up into the Stratosphere! The general rule of thumb for achieving correct VTA is that the headshell/cartridge should be parallel to the surface of the record. Something which hasn't been mentioned in a long time is the effect of the Lenco's superior speed stability on both VTA and the tracking abilities of various cartridges. I've found that lots of the reported brightnesses and hardenings caused by too-high VTA are due to the nasty belt-drive speed instability, mitigated and sometimes even eliminated by the Lenco and other large idler-wheel drives (one reason for their "rich", juicy sound): just check out the VTA on the early Lencos posted under my system. Though dramatic VTA discrepancy by audiophile standards, cartridges so set up in the Rega were not bright, and in fact I lived with vintage MMs, current MMs and high-end MCs for going on 12 years with no audible sonic penalties with the Rega set up in the original Lenco hole. Not only that, but cartridges previously known for poor tracking (usually MCs) tracked superbly when set up on the Lenco! A case in point, the Kiseki Blue Silverspot, notorious mistracker, which tracked like a Shure V15 in my rig for over a decade.

That said, if designing from scratch, then one should build the plinth so correct VTA and geometry can be dialed-in. Like Mario said, the Rega best achieves a "universal" correct VTA for most cartridges when it is flush-mounted to whatever surface the Lenco rests on. Again as Mario points out, if you lower the tonearm-board relative to the surface the Lenco rests on, you can raise the Rega with spacers or after-market VTA risers. For most tonearms - the majority of which are VTA adjustable - I lower the tonearm-board relative to the surface as much as 3/8". While you can compensate by raising VTA, if it is already too high, you're screwed. Good luck with your project!!

As to Mass, while Mass is Class, I find that the "magic" weight - at which point the Lenco not only improves but transforms upwards to a whole new Level of Being (perhaps the Best in the World, GASP!) - is reached at 70-80 pounds, after which it is just more improvements. I design in order to be practical: the magic weight is 80 pounds or so, more than this will be a problem both in the present and in the future, and is already a challenge.

Hi Tessera, the main aim of the plinth is to be sonically neutral, and, by means of mass, nail the Lenco to the ground so that the wheel only drives the platter, and the mass "sinks" all the noise/vibration. Baltic Birch (of the Russian/thin layer variety) is heavier than maple, so more mass concentrated in a smaller volume. Furthermore, it is made up of thin laminations, glued cross-grain to each other, and so further eliminates/controls vibration/noise. MDF is even heavier, and can be easily worked. Back at the beginning of the original thread when all I wanted was to get the Lenco/Idler ball rolling, I didn't take the materials SO seriously (though I did in my very first plinths, which were made of a variety of sound-deadening and sonically "superior" materials such as plaster and Corian etc.), and just encouraged all to follow their favourite recipes/theories.

In fact, I didn't believe materials impacted the Lenco greatly, that all it needed was weight/mass (and this is still largely true), and I believed a total mass of 40 was likely as good as it got, more not being necessary. This view changed when Dopogue asked me to build him a plinth which could accommodate two tonearms, and when I tested it out (at a total weight of just over 70 pounds) my jaw hit the floor. It was then I began to advise the Giant Lencos. Similarly the baltic-birch/MDF recipe: while I generally recommended this combination, it was because it was available, relatively cheap, and very heavy, and as written, the birch was laminated. I built several Lencos before I tried this recipe, even though I recommended it, but when I did, I certainly heard - as with the Giant Lenco - an improvement, in frequency extension, in weight, in PRaT, gestalt, flow and in dynamics. Not to mention neutrality. And from that day forth this is the recipe I adopted (mass/weight, neutrality, frequency extension, dynamics, PRaT).

Now maple sounds great, and I find walnut sounds even better, but these are both coloured. So, I follow the following philosophy: build the plinth so it is tonally and dynamically neutral (i.e. extract the best of both). Once you know the 'table/plinth is neutral, the Source, THEN you can experiment to your heart's content with tonearm boards, and know you're hearing the material combination of tonearm board/tonearm/cartridge, and not the plinth. This will also allow you to find the best material for a tonearm board (more experimentation ahead). Currently I favour maple and walnut for their excellent sonic characteristics, but I should probably at some point chase the ideal of sonic neutrality.

Now I can't say whether the MDF might not cancel out the maple's sound (slightly sweet, like the syrup), and it would be a great experiment, but it'll take quite a bit larger plinth to achieve the same weight, which is fine if all you're doing is carrying it from the garage to the living room :-).

At this end I am just about ready to have the Review Lenco lacquered so it can be shipped to Cyprus. I'm cheating: in order to give it an edge, I've made it closer to 100 pounds total weight, being slightly larger in all dimensions at 24 1/2" x 20 1/2" x 7". But, my own Mr. Red is also overweight and oversized, and I cannot hear any appreciable difference between it and the "regular/classic" size. Consider it insurance. It'll be a two-tonearm Lenco, finished in glossy "seafoam green" lacquer, which is to say '57 Chevy Green, with '57 Chevy cream Lenco. All it needs is a muffler :-)!!

Have fun all, and good luck in all your Idler Projects!!

Hey Jean,

Just exactly what do you mean by:

"But, my own Mr. Red is also overweight and oversized, and I cannot hear any appreciable difference between it and the "regular/classic" size"?

I though the giant giant plinth Lenco's were supposed to be yet way better than the "regular/classic" size.

Hi Richard, this is in the context of the post I was responding to from Kravi4ka - "had decided to make it the classic 23X19X6" - which is the Classic Giant as has been a running theme for well over a year now, why is why Kravi4ka refers to it as "classic." It's further explained by my own: "As to Mass, while Mass is Class, I find that the "magic" weight - at which point the Lenco not only improves but transforms upwards to a whole new Level of Being (perhaps the Best in the World, GASP!) - is reached at 70-80 pounds, after which it is just more improvements. I design in order to be practical: the magic weight is 80 pounds or so, more than this will be a problem both in the present and in the future, and is already a challenge."

The Giant Lenco "classic" weight/size as Kravi4ka says, assuming Baltic birch/MDF, is indeed 23" x 19" x 6", which indeed, made my "my jaw hit the floor" exactly as claimed. More than this seems to have MUCH less effect than the transition from 40 pounds to 70-80 pounds. Less than this, considering the HUGE gains made when crossing this size/mass barrier, should only be considered if space constraints are truly insurmountable. Which is why I am shipping a Giant Lenco to Cyprus, though it profoundly affects the cost of the whole enterprise. Perhaps a doubling of the mass over this "magic point" is required to have a profound effect, but I don't think so, and anyway, it is highly impractical. Maybe I'll try it after Greece, but I don't know how I will get it onto the stand!