I had a similar issue with my Kuzma Stabi R turntable that was on a HRS platform sitting on an audio rack. I was getting acoustic feedback resonance between the audio rack and the turntable causing the woofers to pump heavily as soon as the needle hit the record. I had to further isolate my turntable by replacing the regular feet on my HRS platform with low frequency absorbing feet. I suspect that your turntable needs similar isolation.
Sub Sonics and woofer pumping
I have a VPI prime on bear claws sitting on a maple base. Floor is concrete. I use a Nagaoka MP500 cart with going to an ARC PH3se phono pre, then to a Herron 1A preamp. Amp is an ARC Classic 60. Speakers are Thiel CS 2.4’s.
I get pretty aggressive woofer pumping with vinyl.
I’ve lubed my bearings on the table.
my alignment is spot on.
Tracking force at the upper limits of cart.
I’ve added the 2nd pivot point to the 3D arm.
I’ve even switched out the counter wt to a much heavier unit and added a comparable head shell weight to change the total mass of arm. To no avail.
None of these things have had any effect in reducing the pumping.
I REALLY don’t want to use a rumble filter.
I’m left with the conclusion that the cart may not be a match for the arm, even after adding all the extra mass.
Any thoughts or solutions.
I get pretty aggressive woofer pumping with vinyl.
I’ve lubed my bearings on the table.
my alignment is spot on.
Tracking force at the upper limits of cart.
I’ve added the 2nd pivot point to the 3D arm.
I’ve even switched out the counter wt to a much heavier unit and added a comparable head shell weight to change the total mass of arm. To no avail.
None of these things have had any effect in reducing the pumping.
I REALLY don’t want to use a rumble filter.
I’m left with the conclusion that the cart may not be a match for the arm, even after adding all the extra mass.
Any thoughts or solutions.
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- 22 posts total
Its probably the rack. Different approaches can be taken. Here's mine:https://systems.audiogon.com/systems/8367 A good relatively simple way to see if this is indeed the problem is to set your turntable up on the floor. The best rack is no rack and the floor is pretty hard to beat. If the floor is indeed better then we know its the rack. The next step is either a better rack, or use something like a shelf with mass like sand, or springs, or something to help reduce rack vibrations from reaching the turntable. |
- 22 posts total