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I just purchased a used MMF 7.1. Having never owned a MMF before, I am curious:
There seems to be play in the gimbal bearings. If i hold the tonearm (carbon fiber pro-ject tonearm btw) behind the headshell, and apply gentle pressure parallel to the tonearm (back and forth, the tonearm will move ever so slightly (hard to gauge, but less than 1/16" i'm guessing total). Additionally, if I apply gentle pressure perpendicular to the tonearm, right at the bearings, I get the same sort of movement.
More concerning is that when I do either, there is a 'rattle' coming from what I assume are the bearings.
I do not know the age of the turntable or use on it, but I was wondering if that's a normal condition for the tonearm bearings. I have moved the tonearm through it's range of motion in both the vertical and horizontal plane and there is no binding and the range feels smooth in both directions.
I am moving to the 7.1 from a Rega Planar 3 which has the RB300 tonearm which is much different, but does not have this rattle.
Are the bearings worn out or is this how the Pro-Ject carbon fiber tonearm is designed?
Follow Ups:
Hi, knathanson24,
I own two mmf-7 turntables (one purchased new, one used) and what you describe sounds like the bearings are either out of adjustment (by quite a bit) or someone tried to hide a problem by loosening them up. It may seem like the motion is smooth due to the extra play in the arm but if the bearings have been damaged (or are corroded) the looseness can make the problem difficult to detect. The gimbal on your Pro-Ject 7 carbon arm should work smoothly with no discernable play in the bearings, certainly not to the degree you describe. Loose gimbal bearings can cause the tonearm to resonate badly so you need to get the bearings checked and adjusted.I have a mmf-2.1 turntable that required adjustment of the bearings (too tight) and the mmf-7 turntable that I purchased used had a problem with the gimbal bearings and I had to do some maintenance in order to get things into proper adjustment. (I'm comfortable working with fine-tolerance bearings and purchased the Sumiko TBAT bearing tool to do the adjustments.) But like PAR mentioned, I don't recommend that you try making any adjustments unless you're familiar with gimbaled tonearms and comfortable working with fine-tolerance bearings. If possible, have someone who knows what they're doing check and adjust the bearings.
That said, if you decide to keep the turntable but can't find anyone to do the work and want to try to do the adjustments yourself, we can provide some advice.
Regards,
Tom
Edits: 07/16/16
That certainly sounds as if the bearings are not properly adjusted as there should be no discernable play.Adjusting tonearm bearings is a skilled job and if you need to ask IF they need adjusting then I think it reasonable to conclude that you do not have the relevant experience and expertise in this area. Please do not attempt this yourself as it is easy to damage the bearings and you have no way of knowing if you have set the correct loading as factory specified. It would be like like trying to set precise VTF without a gauge and not knowing what the force should be anyway.
I would suggest that you contact Music Hall for their advice.
Edits: 07/16/16
To get the tiny bearing 'just right' is a genuine challenge.
Loose? well they are just loose.
Too tight? even a tiny tiny bit too tight and very bad.
Always better a tiny bit loose than a tiny bit tight.
The secret is almost tight, but not at all. But not loose.
The biggest problem is most bearing adjusters are a PITA.
So half the battle is getting it all just right AND the bearing adjustment nut.screw/device is also tight after finishing. Without the bearings getting messed up AGAIN.
If you can assemble and adjust a watch.. You can easily do the bearings.
I work on Dual turntables, and quite often come across an arm in need of bearing adjustment. Even though these bearings are open and non-lubricated, I cannot see how any of them could have loosened-up without being fooled with.
The only way to adjust these things with any accuracy, is to remove the arm from its mounting board first, then adjust by feel. Easy to do with great accuracy, but too tight, and both the bearings and your records will get ruined.
While someone may have messed them up, since my MMF7 shipped with overly tight bearings (wasn't horrible, but arm didn't float as it should while zero balanced), loose bearings could be the other side of a QC issue.
I'm not familiar with the 7.1, but I did have a 7 that had overly tight bearings. I was able to loosen them very slightly by fabricating a tool that fit into the two small holes in the bearing adjusters. You could probably do the same to take up the play. Project (Sumiko) may even sell a tool for this.
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