I have a Bogen B-52 as well. It's painted Army Green and I saw somewhere on Ebay where one like mine was being sold as an Army Signal Corps turntable. However, the B-52 is not a heavy platter table. I thought that only the heavy platter Lenco's (and Bogens) were the ones that were capable of being turned into audiophile quality tables. Although I also understand that the motors on these tables are all similar. So can I add a heavy platter to my B-52 to reach the L75 level of quality? This puzzles me greatly as my thought was that the heavy platter was determinative of whether such a table could be made to reach the level of quality that experts like JEAN NANTAIS are capable of turning into an audiophile quality table.
You are correct about the heavy-platter Lencos being the ones that can be upgraded into REALLY nice TTs. However, ones like the B52 are not so shabby, and since the motors are the same, you CAN add more mass to the platter, and it will still drive with stability.
Some people in the Lenco "community" have been "doubling up" or "stacking" the heavy platters, creating platters with twice the mass, and therefore much greater inertial momentum. You could do something similar to the B52, perhaps adding another platter atop it, or just a circular slab of a given material. The only concern would be over-stressing the bearing, which is a bit smaller than the bearing for the heavy-platter Lencos. Still, the bearings are over-engineered somewhat to begin with, so adding SOME mass to the platter should be okay.
You COULD even change the whole thing: platter AND bearing, but that would involve more work, as the alignment between the bearing center and the idler wheel should be maintained precisely.
I have an L78, L75 and a Bogen B52 (same as Lenco B52 if I'm not mistaken). I'm using the stock L78 as my main table, despite the usual issues with v-blocks and saggy tonearm stub, as well as it being still spring mounted. All have been in my hands for less than a year.
However, I have the 'desmo" v-blocks in the mail, so when they arrive I anticipate a flurry of activity to replace the blocks, sort the stub, sort the anti-skate weight, clean the bearing and a general fettling, as well as removing the springs and hard mounting the plate to the plinth. This is for the L78.
From there, time permitting (not likely in the next year) I'll plot out and build a new plinth, and install the MAS-282 tonearm I have.
The B52 is in one of those "record player" boxes, with an amp and speaker. The tonearm is broken (stub broke off due to stupidity). I simply haven't any idea of what I'm going to do with it, though the speaker should be a decent project. Too bad the amp is SS.
If you are planning to construct a 'layered" plinth with the whole original Lenco drive mechanisms underneath, there is a template on the Lenco Heaven site which you can download, print out (enlarged) and use to cut the layers from. It will save you a lot of work. It was made for the L75, but with just slight modification will work for other, similar models.
Please let us know how the "desmo" blocks work out for you. There are so many alternatives for V-blocks, it's hard to be sure which route to take, when replacing them.
It might be a fun project to see what you could do to "tweak up" the record-player box unit, adding as much mass and dampening/stiffening as you could, bolting the top-plate down with solid contact, etc... without restricting air-flow too much and overheating the amp (perhaps adding a silent fan?). Since you'd be deliberately transferring vibration into the box/plinth, you might have to isolate the amplifier some, instead of the TT. Add some mu-metal or other shielding, to reduce motor-generated interference in the amp, and to isolate noise from the transformer/amp from the cartridge, etc... Upgrade to high-grade discrete components in the amp. Just challenge yourself to "make a silk purse out of a sow's ear." It would fun to see peoples' jaws drop when they hear "one of those old things" sounding really almost "audiophile" good!
Which part is this mfrench?
Sounds to me like you already
have a heavy plinth. Is the top plate still floating or did you fix it to the plinth?
Ps I see in my cystal ball this is gonna be a looooong thread.
Ooooooh, I hope your crystal ball is correct! If it is, that will be a refreshing change from half of the threads I start, which fall down like lead counterweights!
:scratch2:... And maybe if it stirs a few people to get those Lenco projects moving forward, it won't be a complete waste of server space, either.
