Listening #120 Page 2
Tearing down Jr. for a rebuild was exceedingly simple. The platter and its integral bearing shaft were easy to lift away from the bearing well, the latter held tightly in place with three slot-head machine screws. The twin idler wheels were held in place with E-clips of the usual sort, with fiber washers underneath. Two large nutsone of them integral to the Bakelite control knob itselfheld the motor assembly in place, while four slim bolts held the motor to its own isolation plate. Three bolts and their corresponding nuts were all that kept the idler mechanism fastened to the main plate, which itself is held to the plinth by means of six wood screws.
Easy enough. But my spirits sagged when I saw the condition of those rubber isolation grommets: All seven were cracked and apparently useless. On closer examination, I saw that every one of the grommets was embossed on one side with "LORD ERIE PA." A quick Internet search revealed that the maker of these "Lord mounts," as they're calledLord Manufacturing of Erie, Pennsylvania ("A leader in solutions to noisevibration, and shock!")is still in business. A longer and far more tedious search of the many, many products on the Lord website indicated that Rek-O-Kut's standard grommet was Lord's current part number J-2924-4. Lord doesn't deal with the public, but their Buffalo, New York distributor, RPM Mechanical (www.rpmmech.com), was happy to take my money. The good news: The Lord isolation grommets were only 95¢ each. The bad news: I had to place a minimum order of 50, shipping additional. Knowing that at least three other Rek-O-Kuts are in the hands of friends, I pulled the trigger. Total expense so far: $160.
Far easierand only slightly more costlywas the answer to the problem of worn, dirty idler wheels that seemed to have lost their pliancy. I acted on the advice of a friend and sent my idle pair to Terry Witt, of Terry's Rubber Rollers (www.terrysrubberrollers.com). Witt rejuvenates idler wheels and pinch rollers by replacing old rubber with new and then "truing" the outer surface to near-perfect concentricity; he charges only $35 per wheel for most sizes, plus $5 shipping. Although a performance review will have to wait until next issue, I received my redone Rek-O-Kut idlers just before the copy deadline for this issue, and they appear as new. New total: $240.
Uranus in the house
The hollow plinth that came with my Rek-O-Kut Rondine Jr., and measured 6" high by 13.75" deep by 18.5" wide, was large enough to accommodate only a standard 9" tonearm. It seemed to me that, in order to install the sort of transcription-length tonearm that God surely wants me to use with this turntable, I would have to add between 3" and 3.5" to the plinth's longest dimension. As I began to map out my new plinth, curiosity got the better of me, and I consulted one of the many online calculators for determining the dimensions of rectangles that conform to the legendary Golden Ratio. And I found that, by bumping up the width just the teensiest bit, from the planned 22" to 22¼", the shape of my plinth would be perfectat least when viewed from above. (I could have completed the picture by also making it 81/2" high, but that would have been excessive, even for me.) If you find this distressingand I can't say that I blame youtake comfort in the knowledge that, unlike some audio writers, I did not consult an astrologer before making this or any other important decision.
A single 4' by 8' by ¾" sheet of good-quality birch plywood costs about $50 in my area; with careful cutting, and depending on edge imperfections et al, such a thing can yield as many as 12 individual layers of appropriate dimensions. As it happened, I decided to limit myself to eight layersbut I cut carefully nonetheless, recalling the drudgery of using a sander to true up a multilayer plinth. Out-of-pocket expenses so far: $290. I know people who wouldn't even consider an AC cord that costs so little!
Mounting templates for the Rek-O-Kut Rondine Jr. are available online (most notably from www.vinylengine.com), but you can just as easily do without: The basic opening is a simple rectangle measuring 83/8" by 51/8". Use a grinder or a half-round file to enlarge the opening on the two short ends, so the plinth can accommodate the tip of the motor plate (near end) and the mounting flange of the platter bearing (far end). Then, on both sides of the opening, about 3¼" from the near end, use a jigsaw to make shallow curves to accommodate the isolation grommets on the underside of the main plate. (This can also be done using a 2" hole saw, prior to cutting out the main rectangle.)
I decided ahead of time to partner my Rek-O-Kut Rondine Jr. with the high-value Thomas Schick 12" tonearm ($1675). To ensure the utmost in alignment precision, I'll wait until the Rondine Jr. is installed on its finished plinth, its platter in place, before mapping out and drilling the Schick's top-layer mounting hole. But to guarantee a neat and sufficiently large tonearm cavity in subsequent layers, I mounted the Jr. on layer No.2, drew from the center of the spindle an arc with a radius of 12" (the Schick's mounting dimension), marked the best point along that arc, and drilled a 1 3/8" hole, which I neatly copied onto layers 3 and 4. I also cut identical rectangular channels in layers 2 through 4, for the tonearm cable and its phono plugs to exit, and a similar but larger channel next to the motor cutout of layer 5, allowing the AC cord and plug to exit.
Next month: gluing and sanding the plinth; installing the new isolation grommets; lubricating, reassembling, and installing Jr. (sounds like North Korea!); polishing the platter; and drilling and installing the tonearm. Stay tuned.