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
Hi everyone again!
As part of putting my new B&O devices again in top working order, today I started working on the mechanical part of the Beogram 8000. I successfully cleaned and lubricated again the tonearm carriage (now it moves very quietly and without "effort"), but I have two main questions... I'm sure you will be able to help me.
1) My Beogram has a strange piece of some kind of hard scotch tape in this position:
http://www.flickr.com/photos/18028488@N03/7895786954/
http://www.flickr.com/photos/18028488@N03/7895786686/
It makes it a bit hard for the tonearm carriage to move freely when it gets to that place... They are basically crashing and I see no sense in that. Is this an original part, or is it there for unknown reasons, maybe a previous fix for something else (strange...)?
2) The service manual (page 5-1) says that the upper part of the control arm should be 19.5 mm far from the turntable platter. I regulated everything starting from this assumption, but now the stylus brush is way too high - I had to remove it in order not do damage the stylus. Should I measure the 19.5 mm from the black plastic part or from the aluminium part of the platter?
3) The service manual (page 5-1 again) says that the turntable platter should be 2 mm higher than the cover plate. Again... The aluminium or the black plastic part? I would say the black plastic part, the aluminium staying on the same level as the aluminium cover plate... But... Could you confirm?
Thanks for your help!
Marco
Marco,
I can't really see the scotch tape in the photo but I don't recall any original places for something like this in that area.Are you sure it's tape and not the thin teflon sheet used for the dustcover sliding damper ?If so, it should sit on the inside, where the black plastic part from the hinged damper slides up againstthe frontmost part of the damper housing. Does that make sense ?Glue it back in place using contact glue.
The stylus brush;Take it off and store it in a "safe place".Don't use it.
In most Beograms, setting the platter height to 2mm above the surface, as mentioned in theservice manual, restricts the maximum damping of the subchassis.Adjust the tone- and sensorarms to be horizontal, parallel to the Beogram surfaces etc.Then adjust the platter height to 0-1mm above the aluminum surface surrounding the platter. In otherwords, the aluminum platter surface should be level or just above level with the surrounding aluminum surface.For the Beogram 6006/8000 with the high radial ribs, I like to make it level, for the Beogram 8002 etc. I'vefound the best position to be about ½-1mm higher.It's not important for the playback functionality but it makes removing 12 inch records from the platter easierand it prevents just-too-large-diameter records from rubbing on the alu surround (plus optics).
Martin
Hi Martin,
thank you so much for your help! The "scotch tape" was actually the teflon piece you are talking about. Someone glued in a wrong position, but since the lid is opening and closing flawlessly, I just cut away the exceeding part. Good that you told me, otherwise I may have removed it completely, I couldn't figure out that it was there for a specific reason.
And... Yes, tomorrow I'll adjust the tonearm height again according to your suggestions. Now, with the 19.5 mm, it is way too close to the record. Some records are unplayable, since they are bit thicker than usual and the stylus may crash on their side before reacing the starting position. It's not the only mistake in the english version of the service manual...
The strange thing is, I had to set up the tonearm again in every parameter. I checked the angle of the "record sensing" arm very carefully (using the light as a reference on millimeter paper centered on the record spindle and so on) and it was absolutely perfect, but the tonearm was totally out of place. And the servo mechanism was wayting some 20 platter revolutions before moving the tonearm carriage... Now everything is fine, but I should correct the starting point of the reproduction - after adjusting, it is now too far from the center of the record. But strange that so many things were wrongly set up... Since for sure no one modified the "start" position (which is perfect with the tonearm in a totally wrong angle), it feels like if the turntable was not really well calibrated at the factory... But now it is! :D
Thanks for your helpfulness, I'll keep you updated (while thinking if sending the MMC20CL to Axel in Germany - but only aluminium cantilever there, right?). Tomorrow, refoaming on the MS-150!
Good night,
M.
Hello!
Yes these decks are a bit daunting when it comes to adjusting them, and no, service manuals don't always replace common sense and experience (and Martin is always here for us) but they are sturdy and fixable! Just think of those old caps. The deck may 'sort of' work, but it is wise replacing them. You know where to find a kit!
Axel does provide quartz cantilevers, just ask him for a quote because his options are not all listed on his site!
Good luck!
This is how mine is set click to enlarge). You can see I do use the brush, which in fact can be adjusted: just pull the hairs either way!
But Martin's advice is sound, if badly adjusted it can destroy the cantilever!
The red light appears to be lit; it isn't!
Jacques
Page in old beogram 8000 manual showing 23mm arm height, not 19.5mm as for 8002
002.TIF
The top of the aluminum surface on the BG 8000 should be set flush with the surrounding aluminum deck. Then adjust the detector arm to measure 23 mm from the aluminum surface of the platter to the top of the detector arm.
On the BG 8002, set the top of the platter 1.5 mm to 2 mm above the surrounding deck and adjust the top of the detector arm to 19.5 mm.
Audio-Retro