|
Posted by Romy the Cat on
07-02-2007
|
|
Interesting… I was under suspicion that only Vibraplan allows LF decoupling but here is another California company the offers an alternative solution.
http://www.minusk.com/
The Vibraplans did work fine and the principle was very simple, I read what the Minusk people say:
“Nano-K® vibration isolators employ a revolutionary concept in low-frequency vibration isolation. Vertical-motion isolation is provided by a stiff spring that supports a weight load, combined with a negative-stiffness mechanism (NSM). The net vertical stiffness is made very low without affecting the static load-supporting capability of the spring. Beam-columns connected in series with the vertical-motion isolator provide horizontal-motion isolation. The horizontal stiffness of the beam-columns is reduced by the "beam-column" effect. (A beam-column behaves as a spring combined with an NSM.) The result is a compact passive isolator capable of very low vertical and horizontal natural frequencies and very high internal structural frequencies.”
Well, Vibraplans needed mass and a large footprint to be effective. If the Minusk concept works then it might be as small as 5x5?
Interesting… what somehow will come up with a tube socket with imbedded Minusk conception …
The caT
|
|
|
|
Posted by Romy the Cat on
09-21-2007
|
Well, I do not know folks how about good Vibraplan as a shock absorbers but I do not know what they are saying however I would like those guys who do those white mats to begin to do something for audio...
|
|
|
|
Posted by steverino on
05-12-2014
|
|
fiogf49gjkf0d I ran across this Negative stiffness isolation platform (the anti Viagra??) independently but I should have known the Cat had pounced years earlier. It is hard to tell how much the concept has advanced since 2007 as I only found one firm doing it (Minus K). It sounds rather straightforward in that if you have multiple threat vectors you create a composite which deals with them all concurrently. My understanding is that this platform has components which deal not only with horizontal and vertical displacement but also compensates for tilt. Has anyone tried this or have indirect reports of effectiveness or lack thereof? Looking around I did find a recent article in December 2013 HiFiZine by a Patrick Dillon. Actually it was a pleasantly modest and calm review of the product. He used it under his SME 20/2 turntable. His summary I quote:
"At $2600, you need to be seriously committed to your rig to consider a
Minus K platform but for me, it’s offered the best upgrade in LP
reproduction I’ve experienced since I bought the SME20/2. It is at least
comparable to benefits you might get from spending the same amount on a
new cartridge. It is also better than either the PS Audio PowerBase or
the Gingko Cloud I’ve also tried under my SME. That it requires zero
maintenance and is not attached to air pumps or power cords makes it
even more attractive to me... "
Here are some specs on the Minus K models:
BM-10 Bench Top Vibration Isolation Platform ~2500
| Weight: Approximately 35
lb (16 kg) | | Dimensions: 12.2” W x 12.2”
D x 4.6” H(310mm W x 310mm D x 117mm H) |
This can support up to 100 pounds.
--------------------
BM-1 Bench Top Vibration Isolation Platform ~$4500
Weight: Approximately 80
lb (36 kg)Dimensions: 24" W x 22.5"
D x 9" H(610mm W x 572mm D x 216mm H)
This can support up to 500 pounds.
They have intermediate models between these. Their appearance is slightly nerdy in basic black but not bad looking either.
|
|
|
|
Posted by steverino on
05-12-2014
|
|
fiogf49gjkf0d Missed the edit time limit above. I found another Minus K article by Philip Holmes at Dagogo May 2013. Also positive but notes that load weight is optimized at the upper limit for the platform and performs best with centering of weight.
|
|
|
|
Posted by mem916 on
06-19-2014
|
|
fiogf49gjkf0d I saw one up at the Newport show a few weeks ago. It was underneath some ancient turntable (something out of the 1960's looked like). As I recall the sound in that room was not the worst I heard that day but that's not saying much! I will sat that given the proximity to the speakers and the flimsy structure they had under the minus k it would seem to do its job very well.
|
|
|
|
Posted by Purite Audio on
06-20-2014
|
|
fiogf49gjkf0d I have been trying one of Spiers Robertsons, rolling air diaphragm platforms under my GPA, subjectively it does improve. ass, also tried the Accurion activeisolation,and had a chance to measure the with and without performance.Interesting results,http://www.speirsrobertson.co.uk/
Keith.
|
|
|
|
Posted by Paul S on
06-20-2014
|
|
fiogf49gjkf0d Keith, which models, exactly, did you try, and what are weight restrictions/parameters? Also, will you please add sound/measurement comparison specifics, to flesh out "improve" and "interesting"?
Best regards,
Paul S
|
|
|
|
Posted by Purite Audio on
06-20-2014
|
|
fiogf49gjkf0d Paul the UK Accurion distributor was kind enough to bring a P4 same internally as their 'Silencer' he also bought some accelerometers , we were able to measure the turntable directly on its usual isolation shelf, (GPA Monaco) and then on the active isolation platform.To cut to the chase the bass did sound tighter with the active isolation, but my wooden floor is not ideal.A solid concrete floor ,a solid welded metal table and the turntable placed directly on to the isolator would be the idealThe Spiers Robertson rolling air diaphragm platform is much more reasonably priced and appears to be more suitable for domestic HiFi.it doesn't really start to attenuate until around 4Hz but again subjectively bass is tighter in fact the whole spectrum is sharper.Certainly worth investigating if you use a non suspended turntable.Keith.
|
|
|
|
Posted by Stitch on
06-20-2014
|
|
fiogf49gjkf0d I worked a little bit with those and I compared it to Vibraplane.
The Minus-K are ok, they do a good job BUT they move very easily, they are very wobbly and based on that, you can only use them with center weight Turntables. And based on their size, when you have a wide Turntable, you need a very big Minus-K. Anyway, based on this wobbling, I would use the Minus-K for Preamp, Phonoamp or something like this, but NEVER for a Turntable. It even stated wobbling when I moved the Tonearm out of its rest into the first track. But, I also heard from ONE owner who said, he has no problems with his, he adjusted it very carefully and it is stable. Who knows....The Vibraplane is totally different, it is very stable and works excellent. Everything on it is rock solid and even a Minus-K owner who did visit me, told me, he bought the wrong items. Next time he would choose VP. Even unimportant for a technical unit, but the Minus-K is pretty ugly (height) compared to the elegance of a VP....and the VP his wide enough for all kind of Turntables. I use passive ones for years and I have absolutely no problems with them. They hold air very good, so I never thought about active ones (the distributor lowered the price for those some time ago...it is an interesting option).
But time moved on and now there are more items out there, well done, but very pricy from Halcyonics or Herzan. They are from Hz a touch deeper than Minus-K / VP but I doubt that you can hear that. When you look at the technical datas at Minus-K / VP then you will know how these systems work (they NEED load), it is pure physics and they are done seriously. Not the typical High End crap but it's an individual decision what to choose...
|
|