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
Hello all,
I have been a long time reader, but this is my first post. I recently found an inexpensive Beogram 4004 on Craigslist. It was in perfect shape, and everything appeared to work as it should. The only issue that I found was that the platter is not centered as it should be. When the record spins, it rubs against the edge of the top of the record player, which then causes it to spin a little slowly, which affects the sound.
Is there a way to adjust this?
Thanks!
Yes, there is.
Make sure that the transport locks are fully disengaged.
Remove the top aluminium panels and locate the three spring steel plates that act as the suspension springs. The sub chassis hangs on wires at one end of the plates which are fixed at the other end by a screw thread in oversize holes. Loosen the nuts and move the plates in the direction that you want to turntable to move and retighten the nuts.
Beware that the previous owner has not fitted an underersize drive belt which is pulling the turntable towards the motor so much that the centering adjustment cannot cope.
Replace the top panels and check the turntable is centred there or thereabouts.
Regards Graham
Wrong platter belt ?If too tight, it pulls the platter towards the motor (left front corner).
Martin
EDIT: just noticed Graham beat me to this.
Dillen: Wrong platter belt ?If too tight, it pulls the platter towards the motor (left front corner). Martin EDIT: just noticed Graham beat me to this.
I was up a lot earlier than you this morning Martin!
By the way, the belts arrived on Tuesday, thanks. I have already fitted a set to a Beocord 7000 which is now on it's way to a customer in Northern Ireland. It sounded just perfect after the re-belt.
If the 4004 is same build as the TX2, also the carriage drive belt can pull the floating chassis if too short.
Collecting Vintage B&O is not a hobby, its a lifestyle.
So, I finally had a few minutes to open up the turntable - nice design, being able to access everything from the top. I took off the plinth, and checked the belt. The belt was not tight at all, everything went on and off easily. Next, I had the turntable spin without a record on the platter. When the platter was spinning, I could hear something rubbing. Two wires from the tone arm carriage were rubbing the bottom of the platter. I carefully bent those wires down. There is very little room between the tonearm carriage and underside of the platter.
It looks like I might need to adjust the suspension - how do I do that? The suspension on the 4004 is not as compliant as on my old Beogram 2400.
Also, I watched the belt that moves the tonearm carriage across the record while it was playing. The wheel attached to the belt does not turn continuously as the record played - it seems to stop, then turn, then stop, then turn some more. Is this a problem? The needle tracked across the record correctly.
Thanks for everyone's help!
The carriage motor moving in like steps, is correct, when the pickup is driven toward the middle by the record, the tonearm moves a small steel plate, the steel plate is dimming a lamp pointed to a sensor, when the tonearm moves, the steel plate let light on to the sensor, when sufficient light is there, the carriage motor is activated until the lamp again is dimmed.
As I dont have a 4004 I cant help you with the suspension. Normally there are a up-down adjustment screw or a gap where to insert a screw driver to bend the blade spring, to adjust center, normally a screw to loosen and move the whole blade sideways. Take look at it, its a simple mechanism.
But before adjusting center, take off the belts, Both of them. place the aluminum platter and check center, it should be off center to the right, place the carriage drive belt, place platter and check, the platter should now be a little less to the right side, place the platter drive belt, the platter should now be in center position. If one of the belts pull the platter off center to the left, the belt is too short, if you have problems with speed variations the platter belt is too loose, the carriage drive belt is normally feeling like a bit loose.
There are manuals onsite for silver and gold members