Dillen !!  Peter !!

One for you two experts in the BG4000 field...

Lee

The lack of response makes me wonder if I asked a stupid question. [:'(]

If so, sorry about that, but I aslked because I didn't know the answer.

I am guessing it is not a belt issue, or the Beogram 4000 would not be able to maintain the correct playing speed.

 Jeff

Hi

I'm no expert, but have seen a few 4000's in operation now and when they work correctly the platter spins at the right speed right away.  It doesn't sound like an expensive thing to get fixed though (famous last words!)

Cheers 

Piaf:

I am guessing it is not a belt issue, or the Beogram 4000 would not be able to maintain the correct playing speed.

Don't assume that. It's not about rotational friction (which a 400x Beogram platter doesn't have much), it's about momentum (which it has lots!). A somewhat slipping belt can most certainly maintain correct speed, but it can take quite a while to reach it.

I guess it's easiest to notice when the platter is stopping, not starting. When you have the covers off, keep an eye on the motor spindle when the turntable switches off. If the platter (and belt) keep moving when the motor stops, you have a loose belt.

-mika

Today while playing the Beogram 4000 I took particular notice of how quickly the platter stopped at the end of play and noted that the platter stops just as quickly as the 4002 or 4004.

Perhaps I didn’t explain the “situation” properly, so allow me to try again. When “On” is pressed, the platter starts, but with a distinct shudder, a hesitation, a stumble (you get the idea) while the platter rotates slowly.

However the second the arm drops on to the record, the speed increases and is spot on accurate. (With the handy strobe light, there is no guessing about this.)

I don’t wish to over-state this scenario, but it does “appear” that the speed change is somehow related to the drop of the tonearm and this situation is absolutely consistent.

Now as far as the play quality, the sound is delightful. A good friend sent me a MMC 4000 for use in this turntable, but I am so pleased with the sound quality that I have stayed with my MMC 20CL…. Instead using the gift cartridge in my Beogram 8000.

Anyway, my interest in all this is I don’t want to be damaging this ultra rare (in North America) Beogram 4000. If something is wrong, I would like to take care of it before it becomes a bigger problem.

Thanks for your input.

I don't have the service manual at hand but I will take a look as soon as I do.

It is a fault and a strange one at that, definitely one of the cases I wish'ed, I had on the bench here.

Martin

Piaf:

Perhaps I didn’t explain the “situation” properly, so allow me to try again. When “On” is pressed, the platter starts, but with a distinct shudder, a hesitation, a stumble (you get the idea) while the platter rotates slowly.

 

However the second the arm drops on to the record, the speed increases and is spot on accurate. (With the handy strobe light, there is no guessing about this.)

OK, then it's probably a real problem and I can't even start guessing where. However, have you tried that the speed stabilization is actually dependent on the tone arm and not just happening at the same time when the arm reaches the start point? I.e try interrupting the automatic start sequence with the manual controls before the arm lowers?

Anyway, I don't think you have to worry about damaging the unit, but I don't believe it will get any better with time, either. I'll leave further diagnosing for those of us who have actually worked on these machines... 

-mika
 

Strange fault, Martin? I specialize in finding this sort of thing. (And I wish I didn’t!) I look forward to your learned comments/advice on this peculiar matter.

Mika, that was a great idea of yours, so I tried pressing “On” and then hitting the “Up” button before the arm could drop. It didn’t have any effect, so it is merely a matter of timing, not the dropping of the arm that causes the change in speed.

As I am not normally in the habit of turning this 4000 on and off repeatedly in quick succession, I noticed that after several on/offs that the platter started more quickly and with less hesitation. I maybe wrong about this, but I believe this observation to be correct.

Jeff

It could easily be the belt slipping. Has the belt been renewed recently and if so, are you sure it's of the correct size ?

Try adding a little finger-brake when it plays to see if the belt slips on the motor pulley or the pulley slips on the motor shaft, I've seen this happen only three or four days ago on a 4002.

Martin

Martin,

For reasons too numerous to recount here I have little confidence in the belt having been recently replaced, and even if it were, if indeed it is the correct belt.

If you have the correct belt, I would very much like to purchase it from you…. that way I’ll KNOW the belt is the right one.

I don’t know what the protocol is for exchanging contact information and making payment, but if you’d let me know, I’d appreciate it.

Jeff

Jeff,

I have the correct belt. You have a PM !

Martin

Martin,

Your new belts solved my problem. Thank you so very much!

Jeff