Where does your amp rest?

[MikE]

This question is not limited to just tube amp users. And naturally may be related to your equipment rack, should the two be associated, though some use discrete amp platforms with mono-blocks. Feel free to mention your rack if applicable.

My amp is pearched on top of a modular Lovan (lead-filled) triangle rack. Coupling a custom (triangle) 3cm polished granite slab to the rack are three Tip-Toes with rubber backing. On top of that is another custom platform (20x17x2") of Chevelle Granite; polished top, rock sides. Coupling the two pieces is a combo of three BDR "ThoseThings" carbon fibre bases with the #5 rubber Vibrapods. Amp footers are stock; machined aluminum with rubber end caps.

I experimented, as recommended by another Moth s45 owner, with removing the rubber footers (to improve treble vibrancy) but didn't care for the results. Much like my disinterest with recabling my system to fine-tune the new amp, I've just not gotten around to messin' with various amp footers or platforms. Now that the granite speaker platforms have been decommissioned I need to stick those 1/2" Ebony squares I was using under the stock amp feet... but I still haven't got around to installing the "cryogenic" silver duplex in the new listening room. Maybe tomarrow, but what's the rush, it sounds great with the stock outlet... I know, "cryogenic oulets, Vibrapod footers, carbon fibre"... "you building a stereo or a space ship?!"

MikE

 

[Rob]

tube amps and vibration

Mike,

Vacuum tubes are subject to microphonic effects when physically vibrated. The vibration can come from the surface the amplifier is sitting on, it can come from the mains related magnetic field of the power transformer or power wiring in the chassis pushing and pulling on the other ferrous components in the amp or the chassis itself if steel. It can enter the tube directly from the vibrating air in the room hitting the tube's envelope. Mechanical vibrations can be channeled into the chassis through the power and other cables.

Placing the amp on floating granite slabs is a good idea. Hiding it in a closed on 6 sides granite box would be better. You could make a large box out of 1-1/4" thick plexyglass or lexan and set the amp inside it on rubber feet. Place the big clear box on rubber shockmounts on top of the granite slab. Pass the cables through a solid mass like a brick with the small holes in it and press rope caulking into the holes to affix the cables mechanically to the brick. Place the brick on rubber shock mounts too.

A 5 sided granite shelf with an open front and acoustical foam absorber on the insides and inside the top would help keep air vibration out of the amp while maintaining hand access to the controls and allow recirculation of cooling air.

The first thing you should do is hand select tubes for the ones with the least microphonics for your amp. After that the above steps could make diminishing improvements.

BTW-1, the same techniques ought to work well for turntables.

BTW-2, 1-1/4" Lexguard, the multi layer bullet proof , water clear product costs about $150/sq. ft. or $4800.00 for a 4x8 sheet. I have a few large pieces here waiting for a really special project. It could be turned to make an attractive turntable platter! Looks nice and is almost as heavy as the artificial marble.

Rob

 

[THOR]

You guys are loony

 

[MikE]

Oh Yeah!

After one listen they'd ALL be signing up for the Funny Farm!

MikE

 

[Thatch_Ear]

I have baker's racks on wheels so I can roll em out and get at the wiring easily. For isolation I use these little soft balls made of something that I don't know what is, that come in a larger ball to squish in your hand that you can get at the Store of Knowledge at the mall for 5 bucks. You get maybe 15 balls. A piece of MDF on the shelf and 4 of these balls and you are in business. If you are really worried about it you could use 2 pieces of MDF and 4 more balls. You do have to put some weight on them between 2 flat surfaces for a few days to flatten them a bit to keep your gear from rolling around but that is all the prep you need. And they do work but I only isolate my CD player as I couldn't hear the difference with any thing else. Course my amp weighs in at around 50 lbs and doesnt seem to mind vibrations.

 

[MikE]

Footers, pods and platforms

David -

Have you noticed any negative effects from the decoupling devices and platforms you're using? I'm guessing the soft balls replaced the rigid stock footers. Was there a loss in dynamics, dulling of transient response, overly smoothing or smearing of hamonic information, lack of drive, an enhanced sense of deeper bass but less tightly wound and propulsive.

Basically what effects were noted with the isolation devices; pro and con, and what other materials have you experimented with?

I've used a number of footers of various design and composite along with component platforms and damping pods. Much like cables, or tubes, I've found these devices to help achieve a balance, tonally or dynamically, once I've selected the core components IMS. And like (some) tubes, these devices are typicaly much cheaper than (some) umbilicals, therefore more cost effective. My results have pointed to a few conclusions; 1>. That a variety of materials is better than the use of one type of footer, either in construction design or core composite. 2>. That while I prefer to use a diverse group of materials/devices I've found that maintaining a majority of natural composite devices have yeilded the best results. I'm partial to Ebony, an extremely dense (and expensive) hardwood, but most any good hardwood will work also. I like to use Granite as well but frankly haven't experimented with other types of stone to identify their various triats. 3>. The arrangement of those footers/pods can be as important as the choice of footer/pod used. I usually adhere to the orientation of points down or a combination; two footers points down, one point up. When possible I try to maintain an arrangement of three (3) footers per component. Some companies make footers of various densities and I'll sometimes use a combination of densities. I've even found that when stacking components, that the allignment of the footers for each is important. I try not to have one footer directly above, or below another. I try to off-set them. With my particular amp platforms (two granite slabs seperated by footers) this was particurally critical. 4>. I typically use this configuration with components; Isolation device> coupling/decoupling footers> component> damping device.

MikE

 

[Thatch_Ear]

Mike,
I can't say that using more or less or in different configuration has made much of a difference because there were a only a few things that caught my ear wrong and as soon as they disappear I stop.
You mentioned Ebony. I would imagine that if an interconnect was made simply enough out of the right kind of wires and RCA plugs that if you had the screw on portion of the plug made out of Ebony instead of metal that it would affect the sound at some level because the mechanical transients would be different. The big question is where is it that you meet the point of diminishing returns and if you really want to find out what that point is. Some guys live for finding that point and some will act as if it can never be met.
I love to listen unless I hear something wrong. Then I have to fix it. I have found out to my great frustration that 99.9% of all the things wrong that you hear are from the recordings. The better your gear the more the faults will stick out and sometimes it is hard to tell if the problem is yours or was in the recording studio.
Thatch

 

[MikE]

Ebony Screws?!!!

WARNING!!! Such talk will have the majority asking for your explusion back to the planet "Tweakoid"

MikE

 

[Rob]

Cheap and effective vibration control

If you guys want cheap vibration control surfaces to set turntables and tube amps on don't forget about 2 inch thick 24" X 30" precast concrete patio stones. They can be painted and are HEAVY. I think they only cost about $5 each. Set one on four big block Chevy valve springs, one in each corner, all on top of another identical patio stone and you will have a vibration proof platform like the one that supports the control complex at NORAD inside Cheyenne Mountain.

Rob

 

[Lefty]

Low cost solution to vibration isolation for tube amp?

Well I could recommend packing the amp in a waterproof bag and lowering it to four feet deep in a backyard swimming pool, but I won't..

 

[Thatch_Ear]

Mike,
I thought my answer to be simple compared to your question. Yes I have tried a few different types of isolation materials. Unless you have a platform that will not pick up any vibrations, and your amp,and your wires,and everything else you will not be able to stop all the vibration transients. That is why I used the casing on your RCA as an example. Everything in your system will have a point where it has a sympathetic vibration with your music at a certain level and Hz. Everything is part of your sound system if it is in the same room. Do I worry about this? Nope. Does it change the way I buy things? Not much. Does anyone but me care? Hell no! Does the fact that I know this change my listening habits? Hell no! (that's 2 Hell no's!)
New paragragraph. Mike ( and any and every body else) when you get to a point in audio that you can hear the difference if your amp is isolated or not then you have to consider everything that can vibrate and or create or change a signal. The cover to your RCA plug is I am sure a viable example.Think about whether or not an innert wood or a metal would provide the most mechanical transients. Am I going to change the covers to my RCA plugs? Nope. Do I really care if it is changing the sound in any way? Hell! No!
Being aware and actually giving a hoot are 2 different things. There are a lot of things that I have been made aware of over the years but unless they actually cause problems when I want to listen I don't much care. I know that a lot of little things can add up to something you can hear. As of now either they don't or I am blissfully ignorant of it. Am I open for improvement? Heck you betchya! If it costs a lot of $$? Hell No!!

Did I curse too much?

 

[Thatch_Ear]

Planet Tweekoid? ROFLMAO!! To get this from a guy that uses tombstones and industrial rubber in his Hi Fi gives me a big smile!

Mike,
I love ya!

 

[Thatch_Ear]

Rob,
I thought those were the barracks. Just think about the HQ if they had a staff meeting. Everthing would slide down there!

 

[MikE]

Hell you say?!

No, I'm not sensitive to colorful language. Just because I speak a certain way on-line doesn't mean I speak that way ALL the time!

The points you bring up about "sympathetic vibration with your music at a certain level and Hz. Everything is part of your sound system if in the same room". I've said that for sometime now. But like yourself, unless something is troublesome I do not change for change sake. If the system sounds good I usually leave well enough alone and simply listen and enjoy. Since the new amp I've become either very lazy or dis-interested in fine-tuning, least compared to my previous standards. All of my skeptics will just have to find something else to hoot about!

MikE

 

[Thatch_Ear]

An early AK thread on platforms, isolation and damping. I bet there are a lot more people in AK now that do this than when this was 1st posted.

Anyone have some good and easy methods or materials used for stability under their gear?

 

[Jack G]

Vibratio Absorbtion

I have an old and relatively low(~26") CWD cabinet. My amp is on/in it on top of a Symposium Platform that is on top of a Signal Gauad. I've tried all sorts of footers, cones decouplers etc., and they all have the good and bad points. They also have their own sonic signatures. I settled on the arrangement I have because it has the most benefits(to me), with the least colors added.
Jack

 

[NOSValves]

Rust never Rests

 

[jt1stcav]

Truely effective or just hoopla?

I dunno...I've read it all, from marble, granite, slate, and glass, to thick hunks of solid maple and other hardwoods, with spikes and cones of rubber, brass, and aluminum, gel balls and tennis balls, on platforms filled with air bladders, shot, and sand. Even gemstones placed on top of cabinets, caps, and trannies! Lil' ceramic piggies seem to make the most sense!

Nothin' elaborate for my system (due to a very limited budget)...tempered glass shelving with solid brass cones underneath my amp, pre, and CD player. My NOS tubes aren't microphonic in the least (as far as I can detect), and I've never heard any degraded sonics due to vibrations. Guess I don't have "golden ears" to detect any discrepencies, if any are present.