OK nerds: How to add dynamic damping to a cartridge/arm that does not have it?

The ability to retrofit dynamic damping to a turntable would make more cartridges work in more tone arms. But is there a way to do it?

A million years ago the Shure / Stanton / Pickering brushes were considered a valid solution. Also, remember the paddles on the tone arm that sat in a trough of silicone goo?

Two specific questions for the brain trust:
1- Is there some other approach I am unaware of?
2- Any thoughts on retrofitting any kind of damper are most appreciated. I would love to hear of something off the shelf.

Thanks everyone.
 

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I made a viscous damping setup for my Technics EPA-100 as the KAB does not fit the EPA-100.

Made from scrap Acetal and uses an M3 bolt as the paddle. I performed measurements to verify its effectiveness and the improvement is measurable. One thing I did discover is too much damping is worse than none. I found only a very small amount damping was necessary.

IMG_20210105_105647337.jpg
 
Years ago I made a 16'' Uni-pivot (why, just for fun). Bass was there & deep, but very plummy!! So I made a damper similar to above & it tightened up the base response tremendously. Note you need to use high grade 5 to 8K silicon oil.

Cheers
 
So something for which there are measurable and repeatable differences is snake oil?
There might be 'measurable' differences, but honestly, who really hears any difference that's not in their 'perceived' brains?
I've heard those doctored-up turntables and find that it's all a bunch of BS.
And please, don't hand me that crap about "but but, it's how it is implimented!"
 
The SME 312S comes with a damping trough attached. The trough has a cover and a paddle that screws up or down to adjust the amount of damping applied. The trough system only damps lateral arm motion; it does not affect behaviour over warps; SME says it is to cope with bouncy floors.

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Measurements show, even with full damping and a slightly over filled trough, the degree of damping applied is quite light, but it is there (a reduction of 3 dB in the arm/cartridge resonance peak).

1665014167772.png
 
What happens is - as the arm/cart moves with either warps or eccentricity the arm overshoots and causes the cartridge to output a signal.

A cartridge is a differential transducer - meaning its output is proportional to the differential movement between the cartridge body and stylus, it doesn't matter which one moves the cart will output a signal.

Adding viscous damping limits the overshoot but still allows the stylus to trace the groove. Too much damping can limit movement once this happens those 8.5Hz (in my case) hips get very large and become peaks.

These plots are my EPA-100 with a Technics EPC-205 cartridge. You can see how the 8.5Hz is almost totally eliminated with a very small amount of damping. I've used a 315Hz signwave because it excites the arm/cart much more than than a 1kHz.

300Hz_CW_nodamp1.jpg


300Hz_CW_damp1.jpg

I
 
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