By Juan C. Ayllon
I read that Mark Levinson first introduced a preamp without tone controls in the 1970s, but suspect it was a paramour, tired of being ignored while he adjusted knobs, who was the prime mover. No doubt, this backfired. Like the twitching of a squirrel’s tail, since then audiophiles worldwide have obsessed over ways to tweak and improve their sound systems’ performance.
My latest tweak came about after I re-read the owner’s manual of my Lampizator Lite 7 Digital to Analog Converter (DAC). A passage eschewed the use of cones to isolate this sensitive device from vibration (which, it is argued, causes distortion and smearing of the audio signal) and suggested, instead, that anti-vibration feet with ceramic ball bearings were best.
A Costly Solution -- or Not?
Following an internet search, I realized that commercially available rollerball feet were costly. For example, the Pro Audio Bono PAB 5 feet ranged from 152 to 302 Euros ($186 to $369) -- each. Others were similarly cost prohibitive. So, turned to solutions I could build myself. That’s when I found this Stephen Scharf January 26, 2009 posting post entitled, “Make Your Own Roller Bearing Isolation System for $16.50” in the Tweaks ‘n’ Tips section of the Forums at Stereophile (click here to view). Now Scharf had presented this as a tool to isolate a turntable, but it made perfect sense for my DAC. I Nearly Sharted Scharf recommended buying several packets of Shepherd’s plastic 1 ¾” I.D. non-slip furniture cups, sandwiching a ½”, stainless steel ball bearing or wooden ball between two of them (the concave cups turned inward), with the idea that the ball cause a slight separation between the cups and roll to dissipate lateral vibration energy. Three of these assemblies are placed under a turntable (or, in my case, a DAC). Additionally, he recommended seating them atop a wooden platform with either squash balls protruding from upturned 2 or 3” Quick Caps (available at Home Depot, for example) or, alternatively, an inflated 18” bicycle inner tube or to dampen vertical, subsonic vibrations.
I remembered that my DAC manual recommended the use of ceramic ball bearings, so I selected the Boca 1/2" Inch Si3N4 Silicone Nitride ball bearing. Its online description read, “1/2IN-C S13N4 GR 10 BALLS (EA.) for $9.07 plus shipping. I thought, “Great! I’ll get one packet of 10 ball bearings for ten bucks and a few dollars shipping!”
I picked up Ace Hardware’s version of the Shepherd’s 1 ¾” non-slip furniture cups (called Rubber Grippers, they come in a pack of four for just under $10) and waited for the ball bearings to arrive in the mail. A few weeks later, I opened up a light feeling package from Boca Bearing and found only one half-inch diameter ball bearing inside. “What happened to the other nine?” I shrieked. Contacting them, I was told that the number 10 in their descriptor referred to the grade of the ball, not the number of balls. “That’s why we wrote, ‘each’,” I was told. I felt ill. Turns out that was just fine, as I discovered that when I placed it inside the two cups, it was too small, allowing the sides of the cups to touch, thus failing to provide a free rolling buffer between them. Perhaps Scharf meant to write one inch diameter, but his editor screwed it up, I thought. This suspicion was confirmed when I saw a follow-up posting (click here for link) of the same project in April 12, 2009 (click here to view) , where he cited the use of 25 mm (which is roughly 1”) diameter marbles. “Holy crap”, I thought, “It’s a good thing I didn’t spend a premium for additional ½’ Boca Bearings!”
My Turn
In the end, I decided to purchase one inch diameter chrome-covered steel ball bearings, as ceramic ones that size were cost prohibitive. Also, although I could find cheaper packs of 10 steel balls on Amazon, I decided to buy two four packs from Motion Industries, a local supplier in Waukegan, IL for $14.36 with tax. Sandwiching the ball bearings between rubber grippers on both sides, I tried placing them underneath my DAC but found this very awkward, as the top cup kept slipping off the ball before I extracted my hand after positioning them. This was very frustrating, and when I considered how often I pull my DAC out to tweak it, the thoughts of having to replicate this challenging feat was unbearable! That’s when I remembered reading somewhere as long as the electronics feet clear, simply setting a ball bearing atop a rubber gripper, concave side up, sans the top one would work fine. This proved the perfect solution. In fact, I found placing the DAC atop them easier than situating it on cones. Now in place, I found that, as Scharf wrote, when you push the player sideways, it rocks back and forth, but quickly stops. I like them! Now, the rollerball pucks target horizontal vibrations, while the inner tube or squash ball/Quick Caps solution that Scharf wrote about are designed to address those along the vertical plane. I may address the latter portion of the project someday, however, at the moment, it would be impractical, as the additional height required with an added plinth atop squash balls seated in Quick Caps or bicycle inner tube, for that matter, would make the space my DAC shares with my amplifier uncomfortably and impractically snug. Besides, the flooring in my listening room sits atop a cement slab and, if I’m not mistaken, vertical vibration should be minimal here. Moreover, the Lampizator, himself, Lukasz Fikus, only suggested the ball bearing feet to address vibrations with his DAC. I placed my Lampizator DSD Komputer music server atop another set of three chrome ball bearing/rubber gripper feet and, for now, it’s mission accomplished! And How Does It Sound? Normally, I would try an extended listening session with and without the bearing pucks and compare results. However, this time, I’ll pass. I am currently burning in both my new Odyssey amplifier (which continues to sound better since I purchased it in December) and a very stiff, uber quality power cord -- which makes moving the DAC about its space awkward -- that just arrived yesterday for review. With so much going on in my system, it would be impractical to try and attribute causality. What I can say with confidence, however, is that my system has never sounded better. Whatever vibration issues arise, I am confident that the chrome ball bearings and rubber grippers solution are addressing them quite sufficiently. For now, anyways.
Equipment Used
2 Comments
tom
10/16/2019 02:00:19 am
l woud like advice
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10/16/2019 07:08:03 pm
Hi Tom,
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