ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
This is what BeoWorld is all about - putting together people with expertise in different areas, in order to come up with solutions, which otherwise would not happen alone!
So right from the start, Evan Bunner gets the credit as the engineering man, who turned (literally) my idea and plans into reality.
BACKGROUND
For many years, I have modified turntables, Technics, Dual, Thorens, etc - there is a wealth of info on the web. But generally, performance mods to BeoGrams have not been made - I am reluctant to change its elegant style.
I have been scratching my head for a few years about how to improve BeoGram performance, with the typically "light" sound. I had many ideas from the mods I did to Dual and Thorens, but generally, I couldn't see myself cutting up a BeoGram!!!
Last year, a pair of broken BG1203's showed up in my workshop - totally destroyed, for parts only.
Just for fun, I built one functional BG1203 out of the total parts of 2 machines, along with fabricating some parts from scratch.
Axel made me a custom cartridge with a nude Shibata stylus, and to say the least, I was very impressed with the sound which this machine delivered.
Apart from my time invested, only Axel and Terry (Terry's Rubber Rollers - rebuilt idler tire) had cost me money in the revival of this machine, so I did not feel that if I was to end up with nothing, that there would be a great financial loss.
Based on previous mods I had done, I had an idea - change the platter to a flat platter, without the pegs. But it had to be a BG platter which would look original.
Derek Au (Auric) in the USA found me a parts BG1902 for a couple of $, and sent me the platter and a few other bits.
Even though the BG1902 platter didn't fit, and was heavier, it did play, and gave me the flat platter surface I wanted.
And even when I put on the LP clamp-weight, and the BG1902 platter sank low, and rubbed against the BG2013 chassis, I knew there was a solution here somewhere.
Menahem
ACTION - THE COURAGE TO CUT A BEOGRAM
I thought of 2 BW'ers who have mechanical expertise on lathes - Soren and Evan. Soren's in Mexico (no offense to the postal service), and it was just easier to deal with a US-based man. Many exchanges of emails with Evan resulted in the ideas of a workable center-platter bearing, and Evan got to work.
In the meantime, I had to reduce the total weight of the BG1203's suspended mechanism, so that the suspension springs would not bottom out, with the changes and additions.
I cut the underplatter's structure, as shown. That alone reduced the total weight by 190g. Working in stages - cutting each hole a bit, and then moving to the next hole, repeatedly - prevented heat-buildup deformation of the structure.
Original After Mod
Platter 745g Platter 795g
Underplatter 510g Underplatter 320g
Adapter – Evan 30g
TOTAL 1255g TOTAL 1145g
After the mod, total weight is 110g lighter, which can easily accommodate the new LP-clamp weight of 275g.
Here's the bottom of Evan's bearing, showing the cutouts for the 3 bolts which secure the underplatter to the chassis.
Here's the interior - note the rubber strips on the modified underplatter - just 1mm lift was enough to ensure that the BG1902 platter underside cleared the upper surface of the BG1203 chassis.
Evan's bearing sits perfectly in the center.
RESULTS
And best of all, I like the improvement in the sound - I detected a very pleasant enhanced presence with the triangles and drums on my Paul Mauriat LP.
Menahem Yachad: This is what BeoWorld is all about - putting together people with expertise in different areas, in order to come up with solutions, which otherwise would not happen alone! So right from the start, Evan Bunner gets the credit as the engineering man, who turned (literally) my idea and plans into reality.
I could not agree more. Very happy to have been able to participate in another BeoWorld project collaboration!
Good pun, Menahem! - 'Turning'
Don't give me all the credit however - you were the designer here, the big picture can require serious thought and planning.
Beo4 'til I die!
Nice job - though of course what people like about the 1200 series decks are the daft pegs! The 1203 is very similar to the 2000, which is a slightly lesser version of the 3000 which has the similar platter to the one you have fitted. I am sure better record support is the answer to better sound - a proper rubber mat would in all likelihood be better than the 1900 type platter but would not look as good as the one you have produced.
Peter
Menahem Yachad: Here's the bottom of Evan's bearing, showing the cutouts for the 3 bolts which secure the underplatter to the chassis.
I wish I could have made it prettier (machine finish is much better in my opinion), but all those fixtures I had to use to get that radial pattern and zeroing to that surface created some scuffs. To get rid of them I used a Scotch Brite pad.
However, it does look very good from the top!
Menahem Yachad: Here's the interior - note the rubber strips on the modified underplatter - just 1mm lift was enough to ensure that the BG1902 platter underside cleared the upper surface of the BG1203 chassis. Evan's bearing sits perfectly in the center. RESULTS And best of all, I like the improvement in the sound - I detected a very pleasant enhanced presence with the triangles and drums on my Paul Mauriat LP.
Great job Menahem, excited to see the finished product - very satisfying.
Good job both of you, but I cant say that I like the idea of changing the look of a nice looking 1202 to the 3000 look.
A good part of the sound improvement I'm sure comes from the shibata from Axel, my hearing is not the best anymore, so I stay with the original SP14.
This not to diminish the fun and experience of doing a good job, I would have loved to participate.
Collecting Vintage B&O is not a hobby, its a lifestyle.
mexking:I would have loved to participate.
Evan:I have adjusted the part for production with English drill sizes and dimensions. You can get the drawing here:
I'll stay with the metric system Evan, get used to it, one day even USA will be "civilized"
Working with the Mexicans I have to work both systems everyday, half the population work metric the other half inches.
mexking:I'll stay with the metric system Evan, get used to it, one day even USA will be "civilized" Working with the Mexicans I have to work both systems everyday, half the population work metric the other half inches. Collecting Vintage B&O is not a hobby, its a lifestyle
For finishing surfaces I use 3M maroon hand pads, and specially for copper and alu I use 3M PSA backed micron sheets 60 and 80 micron wetted with water or fine oil, they never run full, and you can use them over and over. I offen use the PSA to glue to machined aluminum pieces, cut the size you want, and use them as a file.
mexking:3M maroon
Oh nooo... Its happening...
I'm getting the urge to make my own billet pieces for my 1202... Help... the virus!
Evan: Oh nooo... Its happening... I'm getting the urge to make my own billet pieces for my 1202... Help... the virus!
On it goes, no way to avoid the virus.
"I cant say that I like the idea of changing the look of a nice looking 1202 to the 3000 look"
But I have the parts from 2 BG1203's, so if I want to sell it (unlikely), I can make it look like the original again very quickly!
Now I have put on a carbon mat, which improves the soundstage even more.
Let's just say I'm very pleased with the results understatement!
Jacques (Chartz) - where's that champagne you put away for John's BG8002?
This is great fun - Once in a while I visit the local stereo stores and listen to their Regas and Projects, and whatever else they have there, and then I come home and listen to my BG4000 and this BG1203, and I do not envy those poor souls who think they can achieve the best sound only by spending thousands on new equipment!