Amp - isolation platform

[Guest Arni]

Hi,

i am currently looking for an isolation platform for my power amp.
what would you recommend and your experience...

not really after the uber expensive ones but reasonable ones that are effective...

 

some info:

- Amp weighs around 50 kgs

-DIMENSIONS (W X H X D)
17-1/2" (44.45cm) x 9-7/16" (23.97cm) (including feet) x 22" (55.88cm) (including front panel, handles and cables)

 

- will be sitting on wood floor boards

 

Has anyone used this?

http://www.auralex.com/product/great-gramma/

thank you

[Darren69]

Hey Arni,

 

I have the Gramma versions for my Parasound JC1's and they are great. Don't use them for the amps anymore since building my hi fi shelving but the new speakers coming will probably end up on them.

 

I don't know if they do anything for the sound but they keep your amp off the floor just fine! They look OK as well.

 

 

[Guest Arni]

Thank you so much Darren for sharing....you have a lovely system there.....

the Auralex Gramma are reasonably price that is why i am leaning towards using them...

 

are they okay to use on wood floor boards? I mean, it will not scratch the wood floor boards ?  

Is it the V2 you are using or the great gramma ?

 

cheers

Arni

Edited April 26, 2017 by Arni

[Darren69]

Arni, glad I saw the thread and could contribute in a meaningful capacity, I don't do that much here, haha!

 

Yes, all good, they sit on the long foam blocks. Nothing would get scratched.

 

Mine are the original Gramma, I think. There's not much too them, upholstered wood (am guessing it's wood), foam and a plastic handle.

 

I am around 96kg and if I stand on mine they might compress towards the floor maybe 10mm. They still remain stable.

 

I thought about selling them but wouldn't get anything for them, considering how cheap they are new.

 

https://www.storedj.com.au/brands/auralex

 

 

 

Edited April 26, 2017 by Darren69

[Guest Arni]

2 minutes ago, Darren69 said:

Arni, glad I saw the thread and could contribute in a meaningful capacity, I don't do that much here, haha!

 

Yes, all good, they sit on the long foam blocks.

 

Mine are the original Gramma, I think. There's not much too them, upholstered wood (am guessing it's wood), foam and a plastic handle.

 

 

Thank you Sir.

[Darren69]

Edited a link into my last post Arni, if you didn't see it.

[Heifetz]

Greetings,

Has anyone experienced this and can attest to the fact that they actually work?

Thx, Bob

[Cafad]

Yes, they work, but they work better under your source.

 

As it says in the thread above I bought one and ended up putting it under my source.  At some point I'll get another one for the amp, but I'm not in a rush.

[Heifetz]

Thx @Cafad

I'm probably interested in something under my subs and speakers.

Are you suggesting that they don't make enough of a difference under your speakers and so you moved them to your amp?

Thx so much, Bob

[Ancientflatulence]

Talk to Mike Lenehan ............... http://www.stereo.net.au/forums/forum/91-lenehan-audio/

[Cafad]

11 minutes ago, Heifetz said:

Thx @Cafad

I'm probably interested in something under my subs and speakers.

Are you suggesting that they don't make enough of a difference under your speakers and so you moved them to your amp?

Thx so much, Bob

I can't see them working under speakers Bob, speakers produce movement in their normal operation and so would wobble around continually and probably smear your sound stage and imaging all over the place.  Sources and amps react to the vibrations in the air (and ground) caused by the speakers and that is what we are trying to treat with an isolation platform.

Or at least, that is my understanding of things.

[rocl444]

a very cheap and effective thing to try is a 20" bike tube, inflated only enough to lift above the valve, between 2 boards.  i have one under my amp and it has made a significant improvement. a couple of puffs of air every 6mths or so. i have another under my WTA tt.

 

turn the tube with the valve pointing outwards before inflating will help make inflating easier.

[frankn]

I'd tend to agree with @Cafad - something like Mike's platforms work best on Sources and Amps.  External vibration.

Internal vibration is another issue but not addressed by this (but is addressed by Stillpoints).

Barry Diament (BD Audio) is a well known  Audio Engineer and consultant.  He is greatly in favour of vibration isolation - as much to speakers as to source and amplifiers - I've copied his DIY recommendations below.  They are the classic innertube + roller bearings.

@rocl444- I also started from innertubes and I ended up using wheelbarrow innertubes as they have the biggest surface area and you are able to experiment with a greater range of air pressure (you want a low-ish pressure that decouples the unit from the floor (or shelf/cabinet) but doesn't collapse.  I put my innertubes on the floor with an Ikea bamboo chopping board (where would we be without Ikea!) on top and the unit sitting on the board.

I've since moved to using Mike's suspension platforms for power-amps and sources. 

There are a number of companies offering isolation platforms - Townsend, Silent Running and others.     

 

Good luck - start with the cheap options 1st and see if you hear an improvement.  Moving up the food-chain gets quickly expensive so you want to convince yourself it is worth it.

Regards  Frank

 

Barry Diament

Some people already understand this to a degree as it relates to loudspeakers.  They understand that a loudspeaker won't begin to show what it can do unless it is placed well away from large surfaces like walls.  This means bookshelf speakers must not be placed on a bookshelf but on stands that will keep them off the floor and can be placed away from walls.  It also means old style corner placement is wrong as it will put the speaker near the junction of two walls, possibly near the floor or ceiling as well.  Move them out of the corners and hear them sound "more expensive".  The difference won't be subtle.

Correct speaker placement is a start but only that.  The room itself contributes significantly to the ultimate sound you hear but that's a subject for another article.  Here, we're talking about your components and how to help them achieve their best performance.

I used to believe the designers and manufacturers of a given component gave me everything I needed to achieve maximum performance in that box the component comes in.  I thought all I had to do was put the components on my shelf, connect the appropriate cables and turn them on.  Thanks to some experimentation on my part, I no longer subscribe to this.

 

What's shakin'?

What I've found is that all of our components are being substantially inhibited from delivering their best because they are subject to external vibrations.  By far, the most sonically and visually degrading are those vibrations in the ground that enter the component via its feet.  These seismic vibrations (the ones very low in frequency and amplitude, so tiny we don't even normally feel them) are creating spurious signals within the sensitive circuitry of your components.  These spurious signals mix with the real music and video signals to distort them, hardening the treble, thinning the bass, muddying the soundstage and annihilating dynamics.  Seismic vibrations add grain to video pictures, ruin color purity and contrast and soften focus.

I'm still having a bit of trouble accepting that the ocean tide or the wind or a truck changing gears 1/4 mile away has such a profound effect on the performance of my audio and video gear.  What I have no trouble with is the results of isolating my gear from these effects.  The performance gains in every parameter I can think of are clear, consistent and repeatable.  Frequency extension into the treble and downward in the bass is improved.  Stereo imaging gets better focused.  The soundstage takes on greater proportions.  Dynamic swings both large and small are more like real life.  Overall, there is a much greater sense of the system getting out of the way, leaving the listener with a considerably increased sense of contact with the recorded event.  The color, contrast, focus and purity of video signals is improved.  None of these changes can be described as subtle, as they are very easy to perceive by all listeners and viewers.  Best of all, the differences between sources (different recordings and different movies) are more easily discerned.  This is important because recordings and movies vary in quality and the ability to perceive qualitative differences speaks of the resolving capabilities of the playback system.

Seismic isolation.  Those two words are the key to knowing what your components can and cannot do.  The benefits extend to loudspeakers as well.  In fact I have yet to find a component that doesn't significantly benefit from seismic isolation.  Some, like source components (for example CD and DVD players) and loudspeakers show the largest improvements but even power strips benefit from seismic isolation.  After all, they too contain electrical signals which are subject to degradation by seismic interference.

How do you achieve seismic isolation?  You have to "float" your components.  Floating is accomplished with the use of simple mechanical low-pass filters.  Mechanical low-pass filter is a fancy way of saying a spring with a resonance frequency in the seismic range.  Every spring has a resonance frequency, which is the number of times it bounces when compressed and released.  If we could float our components and speakers on some type of springs with a resonance frequency of only a few cycles per second or less, we'd be able to prevent the damaging vibrations from entering those components and the gear would be free to perform its best.

Vertical springs aren't enough though.  Vibrations can exist in the horizontal and rotational planes as well.  We need to float the gear both vertically and horizontally.  This is not at all a difficult thing to do and the performance benefits will make you wonder why this isn't much more widely discussed.  More importantly, the benefits will allow you to know the capabilities of your present components.  I guarantee you will be very pleasantly surprised.  In addition, seismic isolation will allow you to judge if a potential component replacement can achieve a meaningful performance improvement.

As awareness of the negative impact vibrations have on component performance increases, so does the opportunity for commerce.  The market is flooded with accessories touted as isolation devices.  There are all sorts of footers (i.e. adjunct feet) from Sorbothane hemispheres and vinyl pods to cones made of various materials.  There are tiny trampolines, so-called magnetic levitation platforms and a host of equipment platform and rack designs all of which claim to isolate your gear from vibrations.  While some of the roller bearing type footers work, most of the other devices merely change the sound by creating a new set of colorations which some listeners confuse with a performance improvement.  These folks ultimately find themselves riding the old merry-go-round again.  Similarly, there are a few platforms and equipment racks which utilize air bearings.  Most of the others on the market merely ensure that your components are not on the floor.  Any of these can be checked very simply.  If they don't bounce at a very low rate, they aren't going to act as mechanical low-pass filters and consequently, they're not going to isolate the components they support from the frequencies that will cause the damage.

There are two simple mechanical low-pass filters you can make in order to achieve seismic isolation in multiple axes, that is, seismic isolation in the vertical, horizontal and rotational planes.  A simple air bearing made from a minimally inflated bicycle tire inner tube will provide seismic isolation in the vertical axis.  Roller bearings will provide it in the horizontal and rotational axes.

After much experimentation, I created my own roller bearing design, Hip Joints© which, partly because of their lower resonant frequency, outperform the commercially available variety.  Similarly, while there are some equipment racks and platforms which utilize air bearings, I created my own design, the Enjoyyourshelf© rack, which features a fully independent suspension for each shelf.  (The world's first piece of furniture with a fully independent suspension!)

 

Roll your own

In order to provide a means of sampling what seismic isolation can do for your system, what follows are instructions for making your own equipment supports.  Items 3, 6, 7 and 8 pertain to roller bearings.  These can be used without air bearings to provide horizontal and rotational isolation only.  Air bearings can be used to provide vertical isolation only, as in those commercial racks and platforms which use air bearings.  Best results however, will be attained by using a combination of these to achieve multiple-axis seismic isolation.

1. Get yourself a bicycle tire inner tube for about $1.99.  I use 18" inner tubes.  The larger the circle described by the inner tube, the easier it is to balance the gear atop it.

2. Obtain a piece of plywood to use as a platform on top of the inner tube.  I use 1" maple ply measuring 20" by 20".

3. Go to a crafts store and purchase 3 wooden, usually pine, Easter egg holders and some marbles for a total of less than $2.

4. Place the inner tube on your shelf.  Inflate it only enough to hold the component up off the shelf.  Too much air and you won't get the benefits.

5. Place the plywood on top of the inner tube.

6. Place the three Easter egg holders on the plywood platform in the largest equilateral triangle that will fit under the gear you are going to support.  I suggest trying your CD player first, though the benefits will add up as you float your other components as well.

7. Place a marble, or even better, a ½" steel ball bearing, in each of the Easter egg holders.

8. Carefully place your component atop the marbles, so they alone support it, holding it up so its own feet do not make contact with the plywood platform.

You have now constructed, for a cost of approximately $5, a simplified Enjoyyourshelf©.  Of course it can be improved upon for added expense but the point here is to demonstrate and share the concept.  If you like what you hear, you can always take the design further.

 

Enjoy

Now you know why my best upgrade advice is "Don't buy any new components".  The application of seismic isolation can turn your existing system into a set of "new" components.

Happy Listening!

 

P.S. While digital devices show some of the greatest performance benefits when seismic isolation techniques are employed, the effects are cumulative and system performance improves as each additional component is "floated".  Your loudspeakers too will show performance improvements, perhaps even more so than your digital devices.

Finally, a caveat:  In my experience so far, there has been only one system that did not show the performance benefits I'm describing.  It turns out that system had two characteristics which must be dealt with first, evidently even higher priorities than vibration isolation:

First, it was connected to a garden variety, el cheapo terminal strip rather than a good AC conditioner.  Second, all equipment cables (line level, speaker and AC) were gathered in a jumble behind the racks.  All three types need to be properly "dressed", to borrow a term from our friends "across the pond" in Great Britain.  That is, they should be separated from each other.

So what I learned from that experience is that "dirty" AC and improper cable routing can obscure even the great benefits provided by vibration isolation.  Only when there is clean AC and proper cable routing has been attended to will the benefits of vibration isolation be evident.

[Heifetz]

Hi,

I'm looking at this:

http://www.auralex.com/product/subdude-ii/

Its main theory is to 'decouple' the spaeker/sub woofer form the floor.

Do you think its just a bad way to depart with one's money?

It states:

The Auralex® SubDude-II™ is a lower profile version of our classic SubDude™ and is perfect for small subwoofers in home theaters and hi-fi systems. This patented isolation platform features a stylish velour covering over an inert structural layer that floats on a cushion of acclaimed Auralex Platfoam™. This carefully engineered solution allows the true sound of your sub to come through by negating resonance artifacts.

Based on the same Auralex technology that famous recording artists use on-stage and in the studio, this carefully chosen combination of specialized materials instantly diminishes structural vibrations, resulting in cleaner and tighter bass, reduced coloration and a more accurate low-frequency response.

The SubDude-II™ is an incredibly effective isolation platform that instantly improves your subwoofer’s performance.

 

he new Auralex® SubDude-IITM and the larger SubDude-HTTM are lower profile versions of our classic SubDude. The SubDude-HT’s expanded size accommodates popular, larger-footprint home theater subwoofers. The design, based on an Auralex patent, features a functionally inert 3/4”, velour-covered, MDF platform supported by a 1” base layer of sturdy Auralex PlatfoamTM that is an effective isolation boundary

to decouple the subwoofer from the floor underneath.

This combination of materials dramatically diminishes structural vibrations and resonances, resulting in reduced coloration, tighter bass and a

perceived extension of the subwoofer’s low-frequency response. 

 

[Steve78]

can we please have some pictures of these DIY bike tube designs?

[frankn]

Actually I've done it both ways floor-Ikea-innertube-unit and also floor-innertube-Ikea-unit.  Pic's from doing it the former.  I don't think it made any difference in performance either way. 

You can isolate any component in a similar way.

[Heifetz]

@frankn

Thank you for your detailed explanation of your isolation devices and advice.

I will make one for my sub woofers and see how it goes. My subs are on carpet which is on a concrete slab.

Bob

[Heifetz]

3 hours ago, frankn said:

8. Carefully place your component atop the marbles, so they alone support it, holding it up so its own feet do not make contact with the plywood platform.

 

I guess one could use cones instead of the 'marbles in the egg cup'. Is that correct?

Bob

 

[HdB]

Not really! The 'marbles' allow the platform to move a bit (a slow frequency rocking motion) in the horizontal plane, and the innertube (air suspension) underneath this, with the intermediate mass, isolates in the vertical plane - cones transfer the vibration instead of isolating/avoiding it - a different mechanism

 

I've looked but never found Barry Diamont's   Enjoyyourshelf©. or the 'Kneejoints' and presume they didn't reach production

 

Diy versions of the Townsends are also pretty simple to make (innertube, plate/tray, sand, top plate)  this seems to have been superceded on their website by the low mass dampened steel tray plus spring systems (a bit different to Mike's high mass tray plus springs) - the prices on the Townsend pages and SRA are pretty 'extreme', IMO 

[frankn]

Go to tnt-audio.com/diy & tweaking - look at the racks/stands section. 

All this is pretty much covered as well

[metal beat]

Interesting thread and thanks to @Darren69 in bringing up the Auralex option.  I too have wood floors and my amp was on a Symposium Ultra combo with Stillpoint Ultra's.  I removed the Symposium to use on another project and set up the Stillpoints directly with to the floorboards.

 

Saw this thread - for $89 I picked up the Auralex Gramma Amp Isolation Platform on Friday.  My expectations were something between zero and 10% of lasting one side of a record before going back to the Stillpoints.

 

What do you know, the first thing I have noticed is the bass is tighter!!

Not sure how or why - probably very little bounce back from the floorboards now so in essence it is better isolated as any excess energy is drained into the foam.  Jury is out whether I have lost a little sparkle up top, but this is staying for a few more weeks and then I will put the Stillpoints back and compare.

 

  If you have too much bass or perhaps want to remove a little brightness, the Auralex could well be ideal.

 

  For $89, its an absolute bargin for what it does.

 

Edited April 30, 2017 by metal beat

[Guest Arni]

Ordered this Auralex Gramma, i'll see what it does...for $89 i guess it's worth trying

 

I'll report back once received and tested...

Edited May 2, 2017 by Arni

[metal beat]

After living with the Auralex platform for the last 6 months, I decided to go back to a Symposium Ultra Platform. After 2 tracks I comparison the Symposium was less detailed and overall seemed a homogenised musical presentation.

My wife was helping me here and we put the amps back onto the Gamma and even my wife said the music was so much better sounding now.  Bass tighter, mids more open and vocals clearer.

These $89 Auralex Gramma Amp or Loudspeaker Isolation Platform are going nowhere.

they might be cheap, but give the Auralex Gramma Amp or Loudspeaker Isolation Platform a try and you may save 1000's    YMMV

[ABG]

@metal beat Thanks for sharing your experiences. Have you tried them under one of your TT's or any other components?

Edited December 16, 2017 by ABG

[metal beat]

14 minutes ago, ABG said:

@metal beat Thanks for sharing your experiences. Have you hem under one of your TT's or any other components?

 

Hi Andrew

 

not tried under anything else.  This too small for my turntables.  I think from memory they do make a turntable platform but that was too small for my fat arsse tables.    you can have a look at Store DJ for the different choices they have,

 

  I am going to buy two more to try under my tube amps.  hopefully they will work, but one thing I have learnt in hifi is that nothing is universal and anything you do interacts slightly different from component to component,

 

cheers