Vibration Control for Lightweight Tube Components


I'm looking for suggestions to isolate a lightweight tube preamp from vibration and resonance. Not acoustic vibration, but physical vibration from the stereo rack. When I touch the shelf the preamp sits upon, the sound can be heard thru the speakers.

I am using a heavy furniture grade stereo rack for my components, all using Herbie's Tenderfeet for isolation, including my TT. The preamp only weighs 7 lbs. and has Herbie's tube dampers applied, but needs to be decoupled from the heavy wood shelf. I've tried the Tenderfeet and Vibrapods under the preamp, but neither provided isolation from vibration.

So, what are owners of lightweight tube preamps and amps using for vibration control? (there is a limited amount of space between the shelves).
lowrider57
I have one word for you, mass on spring.  Almost all effective vibration isolation solutions employ this simple technique.  
It sounds like a microphonic tube. No preamp should be so sensitive to vibration that merely touching its shelf generates sound through the speakers.
It's not the tubes. It's a new Atma-sphere pre, new tubes, and I have also rolled in some other tubes. IMO, the unit needs to absorb vibration or be decoupled from the shelf.

My previous Rogue preamp, also with exposed tubes, experienced the same problem. (it weighed 30 lbs.). I used Herbies as footers and also mass loaded the top to stop the vibration.
It's similar to a footfall issue.
@geoffkait , what do you mean by mass on spring?
@geoffkait , what do you mean by mass on spring?

Any any isolation device that employs airsprings, mechanical springs, tennis balls, bungee cords, etc. operates as a low pass mechanical filter for vibrations, where the component represents the mass.  The springs are selected in terms of how springy they need to be according to how much mass is to be isolated. So for very heavy components the springs would have to be very stiff, otherwise they would compress too much under load.

Lowrider, I’d suggest trying Mapleshade Isoblock 1’s, or the lower priced generic equivalent that I think may be findable at Home Depot or elsewhere. Assuming that their 1.75 inch height can be accommodated. I say this even though the description recommends that they be used only in conjunction with isolation platforms.

Also, are you certain that the mechanical pathway by which shelf vibrations are affecting the preamp is not via the interconnect cables that are connected to it, that are probably resting on the shelf behind the preamp?

Best regards,
-- Al

Al wrote,

"Lowrider, I’d suggest trying Mapleshade Isoblock 1’s, or the lower priced generic equivalent that I think may be findable at Home Depot or elsewhere. Assuming that their 1.75 inch height can be accommodated. I say this even though the description recommends that they be used only in conjunction with isolation platforms."

Ah, the age old conundrum, should I isolate or should I couple?

;-)
The cheapest way to get great isolation: two Baltic Birch plywood shelves with a barely inflated bicycle tire between them, with a trio of roller bearings between the pre-amp and the top BB shelf (this design courtesy of Barry Diament). If you have the dough, a Minus K platform ($2500 or so). Alternative: a trio of the Townshend Audio Seismic Pods (about $750, I believe)
"The cheapest way to get great isolation: two Baltic Birch plywood shelves with a barely inflated bicycle tire between them, with a trio of roller bearings between the pre-amp and the top BB shelf (this design courtesy of Barry Diament). If you have the dough, a Minus K platform ($2500 or so). Alternative: a trio of the Townshend Audio Seismic Pods (about $750, I believe)"

i can do it better and cheaper. The issue with the bicycle inner tube approach is that the surface area of the air bladder/spring is too large relative to the volume. To maximize isolation effectiveness the surface area of the air spring or bladder must be minimized. Besides, a barely inflated inner tube doesn’t provide sufficient pressure/spring rate to actually do anything. That’s kind of the whole point of mass on a spring isolation.

Thanks everybody for the input so far, but I have a theory...
both preamps have exhibited the same problem; both have an exposed tube design on top of the unit.
The preamp sits on a shelf enclosed in thick wood (pine) open in front and back. If the shelf is tapped on, it may create resonances surrounding the unit thru the sides and shelf above it. These resonances may be picked up by the exposed tubes which are in close proximity. (The shelf is 10" high with enough room for air to circulate).
That would explain why a 30 lb. Rogue preamp picked up noise from tapping on the shelf. Does this theory make sense to anybody?

@geoffkait
 Ok thanks, I understand the concept of "mass on spring" now. In addition to the Mapleshade Isoblock 1, following this concept, there are Bright Star IsoNodes for isolation...

http://www.audioadvisor.com/prodinfo.asp?number=BSISO&variation=L4
IYO, would these be a good size and provide the right amount of spring rate?

@almarg ,
Al, as a test I used a wad of bubble-wrap as a cushion under the IC's and was unsuccessful. 

Lowrider,

according to the blurb for the IsoNodes they are vibration control devices as opposed to real (mass on spring) isolation devices. They are not springs nor do they act like springs, in other words. They are apparently some sort of viscoelastic damper. No offense intended to IsoNodes.

"IsoNode Large Isolation Feet are 1.25" wide and .75" tall and are great for integrated amps, preamps, DVD players, CD players, and more. Use them by themselves or with other isolation accessories such as platforms. Adhesive backing is included for easy attachment and positioning on your components."


@geoffkait, I thought they might be "spongy" like the 1/2 tennis ball concept.

The ad goes on to state...
IsoNode feet are specially engineered from a unique polymer that rejects a wide range of vibration trying to enter from underneath the component. The highly compliant IsoNode acts as both a liquid and a solid for superior vibration control. Vibration and resonance that could interfere with the performance of sensitive electronic circuitry are converted instead to extremely minute amounts of heat and harmlessly released.

BTW, I googled "mass on spring" and I see that the spring has a non-negligible mass.
The preamp sits on a shelf enclosed in thick wood (pine) open in front and back. If the shelf is tapped on, it may create resonances surrounding the unit thru the sides and shelf above it. These resonances may be picked up by the exposed tubes which are in close proximity. (The shelf is 10" high with enough room for air to circulate).
That would explain why a 30 lb. Rogue preamp picked up noise from tapping on the shelf. Does this theory make sense to anybody?
I think what you are referring to is known as a "sympathetic vibration" effect.
I suppose the possibility can’t be completely ruled out, but it seems to me to be unlikely. In part because the tube types in the two preamps are different, and also in part because you’ve been using tube dampers. Also, I’ve had many different tube components on pine shelving over the years (what is referred to as 1 inch pine, which is actually about 3/4 inches thick), without a lot of space around the components, and without ever having that kind of problem. Although I don’t think the tubes in any of those components were quite as exposed as the ones in your two preamps. (I have used anti-vibration products under the feet of many of those components, btw. The particular products I’ve used are no longer made, however).

I have no particular knowledge of or thoughts about the IsoNode feet.

Best regards,
-- Al

Thanks for stating your experiences, Al. And as far as my thoughts on "sympathetic vibration" go, you're right about the different tube types and the use of tube dampers. The Rogue used 4 12AU7's which are low noise and rarely microphonic.

In both cases, with the Rogue and the Atma-Sphere, I've removed the stock feet. As mentioned earlier, the only solution to remove the noise with the Rogue was to isolate beneath the unit and mass load on top.

 I wonder if the new lightweight preamp should sit on some MDF with isolation footers between the pine and the MDF.
I run my ModWright LS 36.5 on 3 Daedalus DiD,s isolation devices on a bamboo cutting board from Ikea "Lamplig" on 4 RTOM Moongel dampening gels on my rack. The cutting board and gel pads are very affordable and made a difference but the DiD's on their own are incredible. I wasn't having any issues with noise but per Dan Wright's recommendation tried the DiDs and am floored how they have elevated the sound of my 36.5 to another level. The 36.5 is great on its own but with the DiDs, piano, cymbals, brushes on a snare are much cleaner and have longer decay: the 36.5 breathes more... more open.

Try the IKEA Lamplig with the Moongels first. They're cheap. The cutting board has a grove on one side so face that side down and place four Moongels to the inside edge of the grove. This tweak with shipping is less than $40. The DiD's are $160 ea. and worth it. I only have one set but will be getting another set for my CD player. I tried them under my CD player and they work there as well but the improvement was much greater on my tube preamp. I'm using Herbie Tube Dampers so I was a little surprised how drastic the DiDs improved things. 

If you live close to a Guitar Center or any drum shop you can get Moongels there. Us drummers use Moongel on cymbals and heads to control resonances. Try just the Moongels under the feet of your pre first to see if that alone works. A package of six gels is $7.
Lowrider57 wrote,

"@geoffkait, I thought they might be "spongy" like the 1/2 tennis ball concept."

-- tennis balls or 1/2 tennis balls don’t have the right spring action to act like a real spring either. You actually need to match the spring rate of the springs to the mass of the component. I’m not saying tennis balls or bicycle inner tubes or gooey type devices won’t do anything, I’m just saying they’re just not as effective as real isolation devices, like my springs. While gooey or rubbery type materials like these or say Sorbothane might seem like good materials, even perfect materials for audio applications, they seem like such a good idea, right? But they are a pig in a poke. You will do much better with mass on spring plus very hard materials to support the iso device and to support the component on the iso stand, generally speaking. It has been 20 years since the Vibraplane iso stand blew into town. That changed everything.

"The ad goes on to state...
IsoNode feet are specially engineered from a unique polymer that rejects a wide range of vibration trying to enter from underneath the component. The highly compliant IsoNode acts as both a liquid and a solid for superior vibration control. Vibration and resonance that could interfere with the performance of sensitive electronic circuitry are converted instead to extremely minute amounts of heat and harmlessly released."

-- They are apparently viscoelastic in nature and act together with the load as constrained layer dampers. I’m not saying they won’t work to some degree but to deal with very low frequency vibration you need real isolation, as opposed to "vibration control." You can have both, which is why they suggest they can be used UNDER a real iso stand. At least that’s what they say. How you should support a real (mass on spring) iso stand is another issue unto itself as well as how you should mount the component on the iso stand.

"BTW, I googled "mass on spring" and I see that the spring has a non-negligible mass."

-- A spring (steel spring, air bladder or bicycle inner tube or air spring) would usually be what, 1/100 the mass of the component being isolated? Where I come from that’s negligible. My springs are the lightest in the business, coming in at around 1/200 the mass of the load.
Geoff---When you say "I can do it cheaper and better" and "My springs are the lightest in the business", may I take that to mean you market such a product? Can you direct me to a site, or provide contact/product info?
Besides isolation from room vibration from below, you must effectively wick the energy out of the component cabinet as well. adg101 had the cheap isolation aspect nailed! IKEA bamboo chopping/cutting boards are a no-brainer!

Bamboo composite board is rather sophisticated in its combination of polymer/grass density layering and is light, stiff, 18% more rigid than hard rock maple, and will be less likely to store low frequency energy. Not to mention, green and cheap.

The moongels may well do the trick over an audiophile BrightStar Isonodes or other gel gumdrop type footer. These are great below the board, but you will want to couple (wood blocks(to chassis/not under feet), point, etc) the cabinet/chassis of the component to draw either internal energy or airborne acoustic energy from the sheet steel box.

Mass loading on top of a component is advised, if possible for its dampening and absorption properties. Something I have found most effective for this, I no longer know where to source. They were paperweights, leather bags filled with lead shot, used to hold down large architectural roll size drawings. Perhaps diving ballast bags would do the trick and be most cost effective.

Once you eliminate the smearing that these vibrations cause with, cheap DIY solutions, I believe there is no doubt you will be well rewarded, perhaps amazed by the results. Your system background will become way blacker as well. I’ve employed these methods for years on my digital course, tubed preamp, and tubed phonostage with excellent results. I realize your Atma pre offers very little room on top to try to mass load, is it the UV-1 UltraViolet?

Happy Listening!
With a preamp that light, just like a small phonostage, or DAC, what-have-you, you need to be aware of not "loading" the preamp chassis with a heavy mains cable dangling from it, causing an energy path from whatever the cable is also in contact with. Again this is where those shot filled bags could be placed above and below the mains before it enters the preamp to "unload" its effect.


"Geoff---When you say "I can do it cheaper and better" and "My springs are the lightest in the business", may I take that to mean you market such a product? Can you direct me to a site, or provide contact/product info?"

I've been in the business of isolation and vibration control for 20 years as well as many other things.  Currently I offer small steel springs of different spring rates for isolating anything from one pound to 250 pounds. These springs are very low profile so can even be used on submarines.  ;-)

Geoff Kait
machinadynamica.com





@geoffkait , interesting.
"OUR NEW PRODUCT!! - Super compressible MINI ISOLATORS - VERY LOW RATE SPRINGS FOR ISOLATING REALLY LIGHT THINGS."

Are these springs heavy enough to stand on their own? Will a board placed on top with a component be stable?
@geoffkait
Every post you write should be signed like this:
"Geoff Kait
machinadynamica.com"

Anything less is a lack of disclosure and doing a disservice to this community. You've been around long enough and involved in enough controversy to know better. 

It's a shame this has to be brought up again. 
Cheers,
Spencer
Spencer wrote,

@geoffkait
Every post you write should be signed like this:
"Geoff Kait
machinadynamica.com"

Anything less is a lack of disclosure and doing a disservice to this community. You've been around long enough and involved in enough controversy to know better.

It's a shame this has to be brought up again.
Cheers,
Spencer

It's actually never been brought up before.  I thought everyone knew me.  Thanks for being Johnny on the spot, Spence.
Lowrider asked,

"@geoffkait , interesting.
"OUR NEW PRODUCT!! - Super compressible MINI ISOLATORS - VERY LOW RATE SPRINGS FOR ISOLATING REALLY LIGHT THINGS."

Are these springs heavy enough to stand on their own? Will a board placed on top with a component be stable?"

I have several types of springs.  They should be used in sets of four or more.  They are very stable when used with the proper weight.  They are especially stable being low profile compared to larger springs I used to sell. As I said earlier the springs will isolate any component - with or without a board - weighing from 1 lb to 250 lb, depending on which spring is selected.  Obviously the heavier the component the stiffer the spring has to be since you obviously want to avoid compressing the springs to the point where the coils start to touch. If you use a board you need to add the weight of the board to the weight of the component to get total weight so I know which springs to send. For example, a preamp weighs 8 lb and the board weighs 4 lb, the total weight is 12 lb. Thus 3 or 4 of the medium stiffness springs will be appropriate for that load.
I'm now convinced that I should use a suspension system for isolation. I'm going to take adg101's advice and use a bamboo cutting board with either the Moongels or geoffkait's springs beneath it.
Thanks to all for your input.

@r_f_sayles, thanks for the detailed explanation and the preamp is a UV-1.

With a preamp that light, just like a small phonostage, or DAC, what-have-you, you need to be aware of not "loading" the preamp chassis with a heavy mains cable dangling from it, causing an energy path from whatever the cable is also in contact with.
I did think about that and swapped the heavy Audience cable with the stock PC for now. I'm also supporting the ICs so they don't hang on the shelf.
Good point about the power cord or ICs tending to pull the component down on one side, ruining the isolation effectiveness or, in the case of CD players, putting the CD transport out of absolute level, unless the power cord and ICs are suspended or otherwise dealt with. I also want to point out that my new Super Stiff Springs are the ticket for very heavy objects such as VPI turntables, Verdier turntables, really big amplifiers such as the Classe flagship. Four Super Stiff Springs will support and isolate objects up to around 150 lb. Use five Super Stiff Springs for a 200 lb object and so forth. Give me the right spring and I’ll isolate the world.

Lowrider57, I encourage using whatever mains cable makes your preamp sound best and then just try to relieve any hanging weight with some kind of support, even a pull-tie noose with the cable hanging, creating a service loop would do the trick and remove the transference of energy by relieving the tension.

Do let us know about your progress in vibration control as it comes together. We look forward to your impressions as you get closer to your music.

As a side note: I would love to add a Atma preamp to my kit, I have had MA-1 Silvers for quite some time and have heard the compo, and it's magic. Otherwise, could not be happier. 

Happy Listening!
Lowrider, I have been following this thread and am very interested in hearing the results of any implementations you employ.  My concerns regarding vibrations are primarily directed at draining them from equipment. Thanks!
One idea for the problem of heavy cables pulling up components is the lead/brass discs that a few companies sell. IMHE, they work well sonically especially when placed over power supplies. So often 2 discs does the trick, one centered to offset the cable pulling and the other over where the power cable connects. 

For vibration draining, another solution I didn't see mentioned in this thread is the ball bearing & cup type products such as Symposium Rollerblocks. They are very effective under my preamp and phono stage, probably under digital gear too. I thought these are pretty popular here, but since they are nothing new, perhaps there isn't anything new to say...Cheers,
Spencer
Spencer---Actually, in my post way up above I mentioned placing a trio of roller bearings (the generic term for what Symposium calls their Roller Block) between the pre-amp and Baltic Birch plywood shelf I suggested. I didn’t name a specific brand (such as Symposium) because there are a few people making them.
Since there are six count ’em directions of motion for which isolation would need to be applied and since springs isolate quite well in the vertical direction and isolate somewhat less well in two of the rotational directions and, practically speaking, not at all in the twist rotational direction or in the horizontal plane, a comprehensive solution would be mechanical springs plus roller bearings, which are rather good at isolating in the twist direction and the other two rotational directions as well as the horizontal plane, but hardly at all in the vertical direction. Voila!
Mass loading on top of a component is advised, if possible for its dampening and absorption properties. Something I have found most effective for this, I no longer know where to source. They were paperweights, leather bags filled with lead shot, used to hold down large architectural roll size drawings. Perhaps diving ballast bags would do the trick and be most cost effective.
@r_f_sayles, I plan on mass loading if I can find some weights that are only 2" wide. It made a significant improvement in sonics to my previous preamp. I’ve been looking thru my house and workshop for a DIY solution.
Maybe some calibration weights for a triple-beam scale. Too bad I got rid of my scale years ago, LOL.
Yes, I mass loaded my amp, pre, disc player. I used barbell weights with 1/8” cork bottoms. I didn’t have your spatial constraint however. I am sure you can find something at a hardware/farm store that would provide an inexpensive solution. Happy hunting!

Gee, funny no one mentioned Herbies tube dampers for all tubes, rectifiers, 6SN7s, 12AX7s, you name it. Would you believe two dampers per output tube and rectifier often sounds better than one? One on the glass, the other on the base. Yeah, I know, that's more than the cost of your tubes just for the dampers.  And of course the transformer needs to be wrapped with mu metal (and physically damped).  The tubes are sitting right in from of that big honking magnetic field.  Hel-looo! And now sis the time for the cork, isolating the circuit boards. 
@geoffkait, I’m using Herbies tube dampers. In the past, I found that 2 dampers would deaden the sound. But I never tried a damper on the base.

@mesch , great minds think alike. I used 2 1/2 lb. barbell weights with cork on some components as well.
Lowrider57 wrote,

@geoffkait, I’m using Herbies tube dampers. In the past, I found that 2 dampers would deaden the sound. But I never tried a damper on the base."

obviously one can over-damp the tube or anything for that matter. As I’m sure you know the sound is quite sensitive to exactly where on the glass the damper is placed. The ideal location appears to be wherever the getter is located. So on a bottom getter tube the damper would be placed around the glass down near the base of the tube, assuming it has a base. The Sylvania Badboys have bases and so does the Tung Sol rectifier, for example.
Lowrider, yes so many tweeks can be DIY at little cost. Make my own cable risers, not sure of the affect, but they look cool. Also, thanks, seldom am I accused of having a ‘great mind’. 


Geoffkait, My preamp has those metal cylinders over the tubes. Can tube dampers be used in this case? Also, I have some of the red and what I will call “o-ring’ dampers. What do you think of those? 
Mesch wrote,

Geoffkait, My preamp has those metal cylinders over the tubes. Can tube dampers be used in this case? Also, I have some of the red and what I will call “o-ring’ dampers. What do you think of those?

Don't know if the tube dampers can be used on metal type tubes, but maybe.  Check with Herbies Lab to see what he says.  Might be worth a shot. I don't actually like those elastomer o rings, actually I never found anything other than Herbies dampers to do anything except hurt the sound. 

Geoffkait, thanks for that. I think I will check out Herbies and also the mu metal wrap. What do you use to physically damp the transformers?
Tube shields can be removed and Herbies dampers used instead for better sonics, less microphonics. Tube shields are used for RF Interference. Are you using a Jolida? 

http://m.wisegeek.com/what-is-a-tube-shield.htm
Lowrider, Yes I am using the Jolida Fusion w/out any mods. Was thinking that as well as I haven’t heard a problem with RF in my system, and also thinking  I may wrap the transformers with the mu metal as Geoffkait recommends. Will depend on the cost of the Herbies as I have 4  tubes to treat.

mesch, if you're using short runs of cables, separate your components from power supplies and avoid coiling power cables, etc., you most likely wouldn't experience a EMF/RFI problem. Do you use any conditioning or a surge protector with filters?

For $15 per tube damper, you could get tighter bass and possibly a more focused image. It's a great tweak.
It's your IC's guarantee it. 
It's your IC's guarantee it.
They are unbalanced ICs, Purist Musaeous and Grover Huffman Empress and I'm not sure if they're shielded.
So, is there a solution to prevent extraneous sound from traveling thru a cable?
So, in other news, while I’m waiting for my bamboo board and Moongels to be delivered, I installed Bright Star IsoNode Feet under my preamp.

The sound of my system is more transparent, with much more low-end detail than when using the Vibrapods or Herbie’s Tenderfeet. This softer, more compliant material works better on a lightweight component.

But still picking up resonances from the shelf.
Lowrider, your advise is well taken. I take care care of cable placement and only use lengths that are needed and they are not crossed. Interconnects don’t touch the floor. Speaker cables on risers. 

Just to be clear, I don’t believe I have any issues with RFI. My concern is with vibrations induced into components via room sound pressure or developed within the component, as by transformers. I dedicated room has a concrete floor. My equipment shelf sits on spikes, is filled with sand, and has 2” maple shelves. My AMP is on its own stand.

As you and Geoffkait advised, I intend to purchase the Herbies dampers for my Pre.  

Thanks for allowing me to interact on your thread.


mesch, May I interject, are your metal boxed components sitting on their manufacturers (rubber) supplied feet, on the maple shelves? Or have you tried coupling them by putting wood blocks, points (points down), or what-have-you, from the chassis to the shelf? The later scheme would act as a drain of energy from the component rather than isolating the energy within the component which the former would likely do.
I'm pleased to report that my problem with resonance between my rack unit and the preamp has been resolved. Using the IKEA bamboo cutting board with the Moongels underneath was the solution. So, a big thank you to adg101 for sharing this cheap tweak with me.

I'm using a 17"x11" bamboo board with 4 Moongels at the corners, and 2 in the center. The pine shelf has been completely dampened and this bamboo shelf with the preamp is now isolated.
I have the Bright Star IsoNode's under the preamp chassis and the sonics are really outstanding.

I use Peter Erskine's "Dream Flight" as one of my reference CDs and this jazz quartet sounds so live, that I feel like I'm in the same room with them. The presentation is more forward and I've never heard such inner detail from my system.
However, symphonic music is sounding too lean for my taste; clearly the bamboo is causing a different timbre than the pine shelf. The detail in the orchestra is just right and the layering between instrument sections is very realistic. Strings are smooth, but lack the warmth I am used to hearing.
I guess this is what a transparent, neutral system sounds like.

Thanks to everybody who participated in this thread.
R_f_sayles, I am not currently using points under my equipment, however have often thought to try some. Would the brass types be best?  Might also look into the Bright Star IsoNodes. 

Lowrider, thanks for your thread, I enjoyed the participation! 

I think the bamboo is causing too much of a "live" sound. The mids are sounding lean from my Gallo's which have previously had a lush presentation.
 Would maple be a better platform, possibly warmer?