Building high-end 'tables cheap at Home Despot II

Hi Kravi4ka...

Welcome to the Brotherhood ! You know, the real answer to your question "How BIG is big enough ?" is answered with another question: "How much weight can YOU stand to live with ?".

I recently finished a Monster-Class plinth of BB/MDF, and with platter installed it weighs in at 87 lbs. In the beginning, I had mad dreams of 100+ lbs, but Jean cautioned me against building something that could cause personal injury in years to come (after all, this is a TT-for-Life !). The final result is now just managable, with the platter removed.

The panels began as 23" x 20", with a total weight of approximately 90 lbs. Many saw & router cuts later, the 11 layers (wood alone) weighed 74 lbs. With something that thick, you'll find it convenient to make removable armboards... which also opens the door to experimenting with various materials for mounting your RB250. I have maple boards right now, but "soon" will be making alternate boards from walnut & something that seems to be ebony.

You didn't mention which Lenco model you have. Depending on the geometry of top plate and platter, you may decide to cut the corner of the top plate, or rotate the unit 90 degrees, as seen in many of the recent Monsters Lencos here, and on other Lenco boards.

In any event, you'll need to think (and measure, measure, measure) to get your RB250 in the right position for "correct" VTA (and remember to account for the size of the Denon 103). One advantage of individual armboards is you get to make them in the appropriate thickness for proper VTA.

Good luck with your planning, and keep us informed on your progress.
Cheers...
Grant

Hi Gjwaudio,

Thanks for the response, that's what I was looking for.I have actually two Lencos-L75 and an L78, the latter is in better shape but both are supposed to be totally rebuilt and I have already ordered the oilite bushings, the Joel kit from e-bay and a bunch of ceramic balls to try on the bearing. I will just rotate the base and I plan to glass reinforce it and seal the hole of the oroginal arm. There comes the difficult part-the arm bord. I see all kinds of shapes of boards on e-bay-rectangular, kidney shapes and round ones, I have several exotic woods to try such as sandalwood, padouk, panga panga, and of course oak and cherry. I will have to calculate how tall it should be and how to attach it to the plinth... But the VTA is the real problem, I still haven't found "Arm setting for Dummies" and if you can help me with a link or something it would be great. Thanks for the answer again, I intend to make the work as precise as possible with a lot of pictures that might help people like me. Best regards from Bulgaria!

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!!