Beogram 5500 turntable speed at the end.

[Ismo]

Hi,

I have a problem with Beogram 5500 Turntable speed at the very end of play. It is hearable that the speed changes. Usually during the last song of the record. I believe it has something to do with the speed stylys travels(slower at the end of LP).  I have new drive belt so that is not the problem. I suspect the drive motor has worn. Has someone had same kind of problem ? And is there possibility to buy drive motor somewhere ? I tried google but seems that drive motor is quite rare, couple of servo motors I could find only.

Regards

Ismo

[Dillen]

A very low platter/subchassis setting can often cause wow.
Reason: A 12″ record is a larger diameter than the platter and the wow comes when the record touches the
surrounding surface – gradually increasing as the tonearm and carriage move inwards, shifting the subchassis’ center of gravity.
First tracks play fine, later tracks not.
The solution is to tighten up the suspension a little at the left/rear.

Don’t overdo.
Make sure the subchassis is still able to move freely.

Martin

[Ismo]

I have adjusted the platter higher earlier. Tha caused different error back then. I dont think that is the case this time.

[Dillen]

Can we see a photo of your Beogram with the platter height visible?

Martin

[Ismo]

Unfortunately I am away now but next weekend I try to take photo. I saw a similar photo here before and after adjustment. The latter looked as my player. I had this clunking sound at the end of play and then I adjusted that platter higher and centered. That helped back then. I still believe its the drive motor fault. 2 new belts tried out and no change. I also ordered new servo motor belt just because it was worn also, waiting for that.

 

-ismo-

[Die_Bogener]

New belts are sometimes not ok, some have to much tension and are too small. Sometimes the tension is so high that the drives moves to the left side.

Too much tension also stresses the motor and needs to much power, the motor can not regulate it any more and makes “wowow”…

The right tension is very low, just test the belt that it does not work like chewing gum… getting bigger and bigger.

A good belt is stiff and keeps it’s size and dimension, not like a rubber band or chewing gum…

[Ismo]

I also changed now the worn servo belt. I know it has nothing to do with this problem but all belts are changed now. I suspect that there are 2 possibilities, Drive motor is worn, or the voltage of drive motor is not stable. Dont know about is there any signal/control line in motor connector. The platter is adjusted high(see photo). Could measure the voltage with oscilloscope if I had one(multimeter resolution/speed is not high enough). Maybe dismantle and solder all on pcb like on that CD player when it helped…dont know.

[Mark-sf]

I would not suspect the motor in this case based on your symptoms and what you have done to date. You can confirm if you have a 45rpm LP which should make the wow significantly worse if it’s a motor issue. I instead would check the adjustment of the tonearm optical shutter and ensure it is within the i.5 to 2.5 initial rotations and how it behaves toward the end of the record. Since the curve is tighter, if it is not correcting fast enough it can sound like a speed variation.

[Die_Bogener]

You have already replaced the caps of the power supply?

And on the controller?

 

[Ismo]

Hi,

I have no clue about that optical shutter issue and how to check it. I can try 45rpm records, theres couple of those. Capacitors are not changed. Is there any cap kits available for LP player ?

-ismo-

[Mark-sf]

You can find the service manual based upon your 5500 Type at beomanuals.com or if you become a Silver member of this site. The procedure is documented there.

[Author]

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