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

@lewm you may be correct about the oscillating- not enough information right now. I’m re-wiring the tone this weekend with Audionote Silver and silver clips- I’ll have everything apart anyway so I might as well try again. 

fsonic, Mea culpa. A thousand apologies.  It was Holmz who wrote the sentence I quoted (and responded to), not you.

@lewm 

No problem. You are one of my favorite contributors on this Board so I'm glad to have that cleared up.

It is super interesting.
Do you access to a compass like hikers use?
I think even an iPhone with its magnetometer built in might work as a way to see if the mat is somehow magnetised.

Sure, it is possible, that it is somehow related to wiring… but I doubt it.

When I had a 50 Hz hum it was also from a magnetic field, and the coils in a MM or MC cart are effectively a magnetometer.

If it is only doing the pumping when the mat is on, then I would think that removing the mat would be a possible strategy to use to ameliorate the pumping.