Do equipment stands have an impact on electronics?

Tom at Star Sound wrote,

"Geoff, Your saying your springs do not rotate or twist on their vertical axis, more so when they are longer?"

No, I’m not saying that. I’m saying that depending on the number of springs and the spring rate and load they can twist around the vertical. But since multiple springs are generally used the resistance to twist is increased according to the number of springs, so for 3 or 4 springs the resistance to twist is great. My original Nimbus sub Hertz iso decide was relatively free to move in the twist direction as well as the two other rotational directions since it employed a single spring. Recall I just got through saying isolation is proportional to the ease of motion in a direction of interest. And when the component does move it is constrained to move at only one frequency - the resonant frequency of the isolating device. The low pass filter disallows motion in other frequencies, except for the ones below the Fr.

Tom also wrote,

"Your saying your springs don’t have a variable rate of rise and decay time in relation to the amount of force applied? If they do then they are in motion.

I’m not saying the springs don’t move. Of course they move. Hel-loo!

To which Tom added,

"Your saying your springs are immune to the rotational forces of some wave types? The soft spongy materials are only iceing on the layered cake ..the spring being as stable as a layer cake. Anything resting on either of these two transient surfaces will be in motion."

I’m not saying the springs are immune to rotational forces. As I said above it defends on how much lateral support the spring(s) provide. Usually multiple springs mean lots of lateral support thus less isolation in the twist OR other toe rotational directions. That what the degrees of freedom indicates. Most iso systems one sees around are not the full 6 degrees of freedom type, while are more technically challenging. The isolation that springs provide to rotational forces obey the same physical laws as they do for isolating in the vertical direction - they act as low pass mechanical filters. That’s precisely why I mentioned yesterday that mixing different types of iso devices can be rewarding in terms of performance. For example, springs (vertical) plus roller bearing assemblies (twist and rock and roll and some horizontal). So if it’s isolation in the twist or other rotational directions that floats your boat as it were then maybe just use roller bearing assemblies. My original Nimbus could move easily in the twist direction because it employed only a single air spring so it did not have much lateral support, which is both a problem for supporting higher loads and a bonus since the twist isolation is improved over conventional multiple air spring designs. The geometry of my air spring was also superior to the air bladders generally employed by iso devices.

To summarize my answer, the isolation is provided by the ability to move. If the component is resting on a stable solid base (no isolation) it will still move along with the floor and the shaking all over motion the house is forced into by seismic forces, including Earth crust motion (microseisms).

Cheers,

Geoff Kait
Machina Dynamica
"give me a string enough spring and I’ll isolate the world"

dlcockrum

... deep bass frequencies do generate more perceivable vibration into the stand, but I think some of the harmonics of string instruments and drums transmit also.

High volumes are required to feel this. I have my Thiel CS5i's and dual REL Stadium III subs spiked to the concrete slab as well, so lots of low bass (and other) frequencies are being transmitted into the concrete.

I should point out that here in Texas, we have "trampoline" foundations whereby steel rebar cables are laid and put under tension   within the foundation prior to pouring the concrete in order to allow the foundation to move with the soil.

Thanks for the info, Dave. I've never heard of a "trampoline foundation," but I guess it has something to do with the soil you have in Texas. While I'm surprised that you can detect the vibration in your turntable stand as you described, I have to admit that I've never actually tested my stand to see if it's similarly vulnerable to such vibration. I'll put that on my hi-fi to-do list.

Does vibration of any form effect electrical performance in electronics and why?

The why is microphonics. The devices affected are tubes, transistors, film capacitors and cables.

The most microphonic tubes I've seen are frame grid triodes of the 6DJ8/6922 family including the so-called 'super tubes' like the 6H30 and such.
The most microphonic film caps I've seen were military hermetically sealed Teflon caps. They rang like a bell. All film caps have some microphonics though.

I've seen microphonic transistors too. Some so bad that they simply had to be replaced. Usually they have very low microphonics but if you think they have none you're living in a fantasy world.

I've seen interconnect cables make noise simply by moving them. Some cables are far more susceptible than others. Cables are often used inside equipment as are caps, tubes and transistors. So it makes sense to keep the equipment as still as possible for best results.

This is not anything new. The table for our LP mastering lathe is set on adjustable points. The table was made in the late 1940s. On top of the table sits a damping platform on which the lathe resides. It is coupled to the platform by adjustable points.

Inside my Ampex recorders its really obvious that the designers were going to some lengths to reduce microphonic effects, and not just for the sake of the tubes.

So this really should not be a surprise to anyone that this stuff is audible and measurable. The damping controls have in some cases been understood for over 60 years!!

Thanks Atmasphere for providing that very useful information.

It certainly "rings" true for me.

Gotta expect that the experts who make these things and do it well are aware of the issues and address them to some extent accordingly which is surely part of why the good sounding gear sounds good.

As a simple home user, I leave those things to the experts and judge with my ears. At home, I do what I can to minimize vibrations that I can control, like the effects those coming out of my speakers may have. Or those transmitted through the floor or can occur whenever gear does not set on a solid and firm foundation.

My goal is to enjoy great sounding music. Some things are best left to the experts to solve, those who actually provide the gear we use and listen to with pleasure.

mapman

Some things are best left to the experts to solve

Yes, but even top end equipment is built to a price point and after market solutions to these problems can be beneficial -- case in point changing the rubber ring tube dampers on ARC kit to Herbie's dampers (see this thread) -- this is a $500 change on a typical ARC top end tube amp (at retail) and likely many times more than the cost of the rubber rings

Secondly the manufacturer (with some rare exceptions) does not know the circumstances of where/how the equipment may be racked hence the validity of numerous footers and supports such as being discussed in this thread

So many reasons to believe that even a well designed and vibration thought out device can be further optimized