Turntable height

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jgrilo Posted: Wed, Jan 31 2018 3:20 AM

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Hi,

I need some help understanding this spec.

I just got a 6500 that needs a little adjustment of the platter height. Looking straight into the turntable the left side of the platter is slightly taller than the right side. In fact the right side is basically flush with the top surface of the table.

When I put down one of these heavier 180 gram LP's, the record rubs against against the turntable top surface.

The service manual states that the distance from the top plate to the top side of the turntable should be 2.5-3.0 mm. Just to be clear, is this how much the platter sit taller than the turntable surface?

Thanks,

Jorge

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Dillen replied on Wed, Jan 31 2018 6:23 AM

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Yes.
And, having said that, as the record is played and the carriage moves along its rails, the center of gravity shifts slightly in the same direction,
resulting in the left side of the platter going gradually lower and the right side gradually higher.
The ideal adjustment is made with the carriage standing apprx. halfway through playing a 12" record.
This again results in the right side appearing slightly lower than the left side, when the tonearms are parked.

If I'm not mistaken, I serviced this deck prior to you buying it, but it's always a good idea to do these adjustments every time the
deck is moved.

180g records are not standard, but if you want to play one, you can up the platter height to suit by adjusting the leaf springs, and you
can let it stay there also when playing standard records.

Martin

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jgrilo replied on Wed, Jan 31 2018 4:23 PM

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Hi Martin,

Thank you for your reply. (You did service this table before I bought it.)

Yes, I learned the hard way about performing such adjustments prior to doing anything.

Being new to B&O, I was eager to play a record, installed the cartridge (seemed to sit a bit low but what did I know?...) and pushed the play button.

The tone arm moved towards the record but dropped like a rock before reaching the record. The cantilever broke. )-:

I found that the package was probably tossed around during transportation. The shaft was dislodged completely which explains why the tone arm was leaning forward.

Fortunately, I bought the turntable from amazing people (Kirsten and Hans-Henrik) who offered an exchange. 

As I wait for the replacement, I am reading the service manual and making these adjustments, so I don't mess up again the new cartridge.

I'm having a lot of fun doing this too.

I do have one more question. The tone arm still seems a bit low. The 53mm spec I assume is measured from the top of the indicator arm to the floating chassis (manual states "swing"). I measured about 48mm. I can adjust this number closer to 53mm but I am unable to adjust the tone arm itself.

On close inspection with a magnifying lens, I saw that the tiny screw head ("B") seems damaged and I cannot turn it. Is it a problem to keep everything at 48 mm?

Thanks,

-Jorge