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mmf-7 rubbing/friction problem ?

I recently purchase the Music Hall mmf-7 turntable. Unpackaged the unit and did the setup per the instruction manual and all seemed well. Played a few albums and it sounds really good compared to what I had before.

What I noticed is that when the platter is spinning, there is a rubbing or friction sound that happens in time with the rotation. The sound occurs if I remove the platter and just spin the sub platter manually. I'm thinking this rubbing or friction can only result in degraded performance.

I have pulled the subplatter out and it appears fine to the naked eye. There is a shaft from the center of the subplatter that goes into the center of the turntable. It seems to me that this shaft must be rubbing on the insert it slips into. I suppose that some rubbing would have to occur with the rotating shaft. What I'm concerned about is the rubbing/friction sound. Is that normal?

Does anyone have any ideas what the problem might be? Maybe just need some lubrication? Bent, off-center, or off-axis subplatter shaft?

Any help appreciated.

Thanks, Steve
sjhomen
6 responses Add your response
jependleton
155 posts
 
I also have an MMF-7, but have not encountered that problem. There should absolutely be no audible rubbing sound. It could be that the spindle assembly is bent or off center. You may be able to tell more about that by looking underneath the base to see if the bearing assembly looks like it is out of square with the plinth.

One problem that I had when receiving mine was that the sorbothane hemispheres between the plinths were out of position. If the gap between the two plinths was off enough, then this could cause something to rub. This should be easily seen by visual inspection. Also, one of the hemispheres could have slipped toward the center and could be in contact with something. By removing the platter and gently springing the plinths apart, you should be able to get a read on this by using a flashlight. If any are out of position they are pretty easy to put back in the right place.

This is a real nice turntable and a good value. Please let me know if this advice doesn't lead to a fix.
dan_ed
2,451 posts
 
Steve,

Is there any lubricant in the bearing cup? Music Hall recommends 30wt. Mobile One. In addition to that you could try a small dab of molybdinum grease on the upper part of the spindle towards the top of the bearing. I do recall some noise with the MMF 7. Very slight, but noticeable.
telemarc
13 posts
 
I have had no problems with mine and can't hear any rubbing. I have seen a previos post to the fact that a few mmf turntables had bent shafts right out of the box. You should be able to see it if this is the case. One thing I will say is get rid of the felt mat and get a ringmat. I could not believe the difference. Opened everything right up.
sjhomen OP
1 posts
 
Here is a response from Music Hall:
Hi,

It`s not serious.

Try leaving it running for a day or 2. If that doesn`t work, I can send you a bearing thrust plate (The large nut on the bottom of the bearing) and that will solve the problem.

Roy Hall

Any thoughts?
jdcrox
119 posts
 
The Mfgr has spoken! Try Roy's solution first, and if it still rubs then try the new thrust plate. A free solution. I would think if the shaft was bent you should be able to see it in the platter.
I also have the MMF-7 and it is a quite nice sounding table, especially for the money. I also agree with getting rid of the felt mat. I put a Herbie's on mine and it did make a large difference. Plus it is nice not having the mat come off with the record. (I live in a very dry climate where static is a problem).
John
dan_ed
2,451 posts
 
Roy is a good guy. I'd go with his recommendation.
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