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Please help me trouble shoot this.
1. If you have a mmf-5, take the belt off the motor, put on head phones, turn your volume all the way up on your amp, move your tone arm toward the center of the palatter. Do you hear a hum? Turn the volume down, set the neddle on the non moving record closest to the spindal, turn the volume all the way up again. Is the hum louder? Sounds like you're now picking up a vibration?2. Put the belt back on. With the dust cover closed and the tone arm in the cradle, gently put your ear on the dust cover and turn the motor on. Do you hear a hum comming up through the plinth to the dust cover?
If you answer yes to all of these tests, then all are turntable are normal. If you answered no to all or some of these tests, then my turntable is malfunctioning.
Follow Ups:
Seems that im my thinkng the cover will just vibrate adding to the confusion.I did a test with a db meter and played a CD fairly loud with the DB meter sitting on the platter.
It was a higher DB with the cover on, than with it off.
the cover acts like a drum and amplifys the noise and does not reduce outside noises.
I would imagine it would certainly amplify inside turntable noises.
Thus I always remove the cover. also while leveling the turntable the weight of the over will throw the leveling off. So when leveling you have to decide with or without cover.
I also had quite a bit of motor noise and have done alot of experimenting with this deck.First remove the feet, they are a lot of the problem. Get a set of Audioquest Big Feet. Then remove three of the rubber grommets between the plinths leaving three in a triangle. Put three Big Feet under the grommets and the other one to the left of the tonearm on the top plinth. You should also check the motor screws. If they are too loose or too tight it will vibrate more. Also drop the pully down closer to the motor. Motor noise is VERY low now.
As far as the hum when the tonearm gets to the center of the platter , its there but you can't hear it when music is playing.
Just double checking. In total I'll need 8 big feet? 4 to replace the table feet, 3 for placing under the grommets, and one for the tone arm?
Thanks!
Just 4 Big Feet. 3 under the table and 1 next to the tone-arm. I forgot to mention I also removed the anti-skate wire and holder. If the Big Foot next to the tone-arm interferes with the anti-skate just put all 4 under the table.If you are still using the felt mat do a search for the "spot mat" on the vinyl asylum. I used 10 3/4" cork dots in a similar arrangement. Use a small dab of silicone to stick the dots to the platter. Don't use the clamp if you decide to do this. I tried the DIY non-felt mat and the spot mat is much better.
Thanks. I'm puzzled as to what the foot by the tone are is going to do. You placed it on the top plinth? Did you remove your anti skate to accomodate the foot? I don't need the anti skate?I searched spot-mat here and on yahoo. Whew! There are a ton of varations. Sure beats spending $140 on a ring mat!
Some people think anti-skate does more harm than good. I removed it because I felt it caused vibrations in the tone-arm. The Big Feet are made out of sorbathane that is very good at soaking up vibrations. I put it next to the tone-arm to deaden the area around it. They are a little smaller than half a tennis ball and have some mass to them.
Thanks! One last thing. Well maybe two things.
When you originally said to remove three grommets and leave three in a triangle, and then put the big feet under the grommets, I thought you meant directly under the grommets between the plinths. I didn't see how that would fit. I understand now!Do you happen to have a picture of your table you can email me? I'm curious to see it set up.
What do you think about replacing all the grommets with little feet? Too soft?
I think the little feet are to big and would put too much gap between the plinths. But I just found something that might work well. They seem to be the perfect dimension. I am going to try them myself. Here is the link.http://www.needledoctor.com/s.nl/sc.2/category.88/it.A/id.2258/.f
I would be happy to send you pictures of my table, please let me have your e-mail and I will send them sometime next week because I am not home right now.
Hi Guru,Just checking in. Have you been able to try the isonode feet between the plinths yet?
Shoot me an email when you have a chance. dantonow@yahoo.com
Sounds good! I'll check out the site.Here is my yahoo email address:
dantonow@yahoo.com
Thank you so much!I'll try all you suggested! If I was hard pressed on what hum was more bothersome, I'd say it was the motor vibration up through to the top plinth. That seems to be what I hear between tracks and quiet passages! Thanks again!!
I don't believe this is limited to this deck. My deck shows the same hum as the arm gets closer to the spindle and therefore to the motor.
Is this not just the same as when you place electronic components close to each other. You get hum.
Just my two pennies.
Dave
I do not hear any motor noise except in extreme, contrived test conditions such as you describe (headphones, full volume, drive belt removed, geesh!). I did put my ear to the dust cover, and, gasp, I heard a very faint rumble. Horrors!!! There's not 100% complete isolation!!! So what?!?! Spend 10X more and you can still probably come up with a test that will find some noise. Objects moving in air generate sound. It's how the world works. I respectfully suggest that you listen to music (vs. the tone arm), as this is what the MMF-5 was built for, and, in my experience, does a fine job.
Thanks for doing the test!I understand complete silence will never be achieved! Where you heard a faint rumble while your ear was on the dust cover, I hear a LOUD hum, not faint. At normal listening levels wearing headphones, i still hear the motor between tracks. When the record is approaching it's final few tracks the vibration up through the platter and the electrical hum as the cart gets close to the spindal are audible.
Sorry to hear about this... either you have a problem with your TT, or your ears are much better than mine :)
Thanks! I'm going to make a few tweaks. I have to look at it as a challenge and not a problem.
Can't do your test precisely as you wish because I don't have an amplifier with a headphone jack.However, on your # 2, ear to dustcover --- I can hear the motor running but it doesn't sound like "hum" as in 60 cycle hum, just the motor running and some slight vibration transfered up through the dustcover. You could describe it as a humming type sound but it is very faint and again it doesn't sound like 60 cycle hum sounds like.
Cranking the volume on my amplifier with table running, belt off or on, tonearm in cradle, again there is no "hum" as in what 60 cycle hum sounds like. There is a relatively small amount of "hiss" and I can slightly hear the motor running, same sound as what is transferred through the dustcover. A hum type sound but it is very low level and its definitely the sound of the motor. Now maybe magnetic motor noise technically is a 60 cycle hum so maybe I'm describing it wrong. Anyway, moving the tonearm doesn't increase it whatsoever, even as close to the spindle as possible.
In my analog system, there is the MMF-5 with a Shure M97xE cart, a tube phono stage (Cornet) and a hybrid integrated amplifier (Jolida 1501RC) the noise level, even with the volume cranked (100 watt per channel amp) is low level enough that you wouldn't hear it on soft passages of music. You'd have to be pretty close to the speakers to even hear it between tracks and you would hear the "hiss", not the motor noise as that is barely audible up close to the speakers.
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