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So Weird- No Stylus Contact Woofer Pumping with Hana ML and Elac PPA-2

I observed the weirdest thing I have ever seen in audio. With the cartridge positioned above the record, tone arm locked up and platter spinning, the woofers were pumping on my system. I googled every permutation of query I could think of but came back with no hits. That’s when I decided to video the problem- link below:

Mystery Woofer Pumping

I could type out all the details but the video pretty much covers everything. I thought ya’ll might be interested in this.

 

mitchellcp
mphipps's avatar
mphipps
6 posts
 

I didn’t try all my albums- it did it with probably half a dozen.

petg60
1,486 posts
 

Do you have another cartridge to try? That would eliminate some guessing.

dinov's avatar
dinov
862 posts
 

+1 @cleeds feedback. Your turntable is too close to something like a speaker etc.

chocaholic
219 posts
 

I also have a Hana ML cartridge and I do have woofer pumping but only when the needle is in the groove. Do you have that issue as well?  I eventually installed a KAB subsonic filter and all is good. Just wondering if you found some other way to address that. 

mijostyn's avatar
mijostyn
8,570 posts
 

As you look at the video you pick up that the oscillations are rhythmic and that rhythm occurs at 33.3 times per minute. I think @ Lewm hit on it. There is either Iron in the platter or a sensor magnet that is inducing a voltage in the cartridge. That oscillation will cause distortion in the woofer. The solution is a less sensitive cartridge or a different turntable.  

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