Are Isolation Platforms Effective

[av_phile]

What are your recommended Isolation Platforms, if they are effective. Should I get one each under power amps, preamp/processor and cd player. If not, which component will benefit the most? Thanks.

 

[JoeE SP9]

I use isolation platforms under my TT and tubed power amps. IMO they improve the sound of those devices. I seem to have less background noise coming through the vinyl playing process. There are definately fewer microphonics coming from my output tubes. I don't know if they are really needed under most solid state devices. I am open to suggestions or ideas. Maybe one of the anti-tweakers (sic) could wade in.

 

[Mr. Music]

Vibration damping can be very effective but you don't necessarily have to pay a fortune to obtain it. Wall fixtures for shelfs can do a lot.

My amp is placed on two heavy steel shelf fixtures turned upside down with wood under the 4 feets. Works great. The other gear is also mounted on this "Alternative way".

 

[Az B]

There is no way that normal levels of vibration can affect the sound output of a solid state amp, preamp, receiver, or CD/DVD player. Unless the vibration is so bad that it is causing physical damage to connections or to cause the laser to mistrack, there is no problem.

Turntables are a different story. Some are more sensitive than others, but many will pick up subsonics and feedback if not isolated. In some cases, the isolation may need to be pretty extreme.

Tube amps I have no data on how vibration affects the sound. It makes sense that they would be more easily damaged from vibration as the tube themselves are susceptible to vibration damage.

 

[sjdgpt]

From the Voice of Experience.

Isolation platforms can be critical for components with high speed moving parts (think those little CD & DVD motors) that can have problems when exposed to vibration. Hence the manufacturers installing vibration dampening devices inside the players.

How much vibration is a problem?

Freight Trains moving at 60 mph every 30 minutes about 1/16 mile from your house.

It takes that much vibration to actually cause a problem greater than the manufacturers internal vibration dampening device. Even so, the failure rate of those little motors in such an enviroment is only about 3 to 5 times the failure rate of those little motors in all enviroments. In other words, 3 to 5 times an infinitely small number is still an infinitely small number.

What does it take to really minimize the vibration problem? Think concrete or marble built into a table. Lots of weight. Maybe 500lbs of weight. The mount between the table legs and table top is a dampening device. In the old days, we used a bladder filled with a silicon gel. Great stuff.

Is such a vibration table practical for home users? No.

An extended warranty on the CD/DVD player would be cheaper than the cost of the solution, if you actually had such a problem. Personally, just buy a good unit with a minimum of 1 year warranty, skip the extended warranty, and trash the player every three or four years.


Now days, I see all kinds of super duper vibration free tables and 3 mm neoprene pads that are "designed" to reduce vibration, even from trains and automobiles.

Wow.

Remember, at 1/2 mile you can still "feel" the train, but that amount of vibration is not greater than a heavy person walking across a wooden floor.


PS: If you actually had a vibration problem, the playback of the CD/DVD's would be having problems long before actual unit failure.

 

[mtrycrafts]

What are your recommended Isolation Platforms, if they are effective. Should I get one each under power amps, preamp/processor and cd player. If not, which component will benefit the most? Thanks.

Of your listed components, none will benefit from isolation, unless your CD player is already mistrracking, highly unlikely. Do you have any unusual vibration problems in the house/room?

Not even if a CD player is on a speaker blasting at 120 dB spl:

"CD Magic", Pholmann, Ken C., Stereo Review, July 91, pg 39-42.

Turn tables would benefit the most.

 

[Rip Van Woofer]

Solid state electronics do not exhibit microphony (literally, to act as a microphone and transmit airborne or physical vibrations) to any significant degree. You'd have to physically thump on the circuitry to make any sound happen. No, don't try it!

Tubes, turntables and phono cartridges can be more microphonic, but it'd have to be a fairly extreme situation. I can recall some TT/phono cartridges in The Old Days getting feedback from nearby speakers. But I think these new megabuck TTs that look like they were made to measure atomic weights or act as ship gyros or something are a bit silly.

I do have some sorbothane isolation thingies under my old TT (they were gifts from a tweaky friend). They might help keep it from skipping when I go galumphing across the room but that's about it.

It's a lot more important to keep your amps cool by allowing air space around them.

 

[Mudcat]

I am in the process of building the ultimate isolation platform for my turntable. I think I get more fun out of making things like this than actually listening to my system.

Starting with one of those 12 inch thick maple butcher blocks 18 x 18 inches wrapped with 1/2 inch thick foam (cheap cushion stuff), sitting in another maple box made from 1 inch thick birds eye maple and measuring 19 x 19 inches inside dimensions and 18 inches deep. The butcher block is sitting on four 8 inch diameter inner tubes from a wheel barrow. All the inner tube valves have the pin removed and are connected to a common manifold to another schrader valve and pressure gauge in the front of the box. Pump to to 10 or 12 psi with a bicycle pump. It will weigh about 70 lbs. Don't really know how helpful it will be, but, it is a fun project (after I finish the cables for Gene).

 

[mtrycrafts]

I am in the process of building the ultimate isolation platform for my turntable. I think I get more fun out of making things like this than actually listening to my system.

Starting with one of those 12 inch thick maple butcher blocks 18 x 18 inches wrapped with 1/2 inch thick foam (cheap cushion stuff), sitting in another maple box made from 1 inch thick birds eye maple and measuring 19 x 19 inches inside dimensions and 18 inches deep. The butcher block is sitting on four 8 inch diameter inner tubes from a wheel barrow. All the inner tube valves have the pin removed and are connected to a common manifold to another schrader valve and pressure gauge in the front of the box. Pump to to 10 or 12 psi with a bicycle pump. It will weigh about 70 lbs. Don't really know how helpful it will be, but, it is a fun project (after I finish the cables for Gene).

And you are going to place this where to listen? In the garage and pipe it to the system?

 

[Mudcat]

And you are going to place this where to listen? In the garage and pipe it to the system?

Do you have any idea how expensive birds eye maple is ( and how good it looks)? It is going to sit just to the right or left of my rack.


http://forums.audioholics.com/forums/showthread.php?t=2380

 

[Rip Van Woofer]

Something else occurred to me about isolating turntables. If I recall the few times back in the day when feedback was a problem with a TT/cartridge combo, sometimes one solution (besides moving the TT farther from the speakers) was to simply lower the dust cover! On the other hand, I think I remember sometimes that a flimsy plastic dust cover made it worse... So covering the TT with some sort of reasonably non-resonant box - maybe even the stock dust cover - might be a more fruitful exercise than isolating it from the shelf. Line it with acoustic foam if you're obsessive/compulsive - like one of those soundproof boxes used with noisy dot-matrix printers! Hey, it'll keep the dust off, too!

Heck, if you have a nice, reasonably thick non-resonant shelf anyway it's unlikely to contribute anything from airborne sound to the TT, right?

Don't know the cost of birds' eye maple. I'm just getting more into woodworking myself--trying to move beyond plywood, MDF, and bondo--and am looking for local hardwood suppliers. Meanwhile, check eBay. If I've learned anything lately it's that you can find dang near anything there eventually!

 

[mtrycrafts]

Do you have any idea how expensive birds eye maple is ( and how good it looks)? It is going to sit just to the right or left of my rack.


http://forums.audioholics.com/forums/showthread.php?t=2380

The wood may look great along witht he workmanship but that whole contraption

 

[JoeE SP9]

I have found that with belt drive TT's removing the dust cover when playing records sounded better than leaving it on. I suppose air born vibration could cause the cover to vibrate and transfer that to the plinth. I have observed "heard" this on several spring suspended TT's based on the original AR design. Linn, VPI and SOTA are the ones that I have personal knowledge of. I have been quite happy with the sound on or off. However having the cover half way up is definately bad.
I believe the commercial name for this type of isolation platform was/is "Seismic Sink". Anyway, I'm going to build one also. It can't hurt, may help and I can make it look good. My rack is quite industrial looking and I'm beginning to want better looks. Who knows, an attractive isolation platform could induce me to buy the black granite shelves I've been wanting. Thank you av phile for giving me a new project to work on

 

[Mudcat]

I have found that with belt drive TT's removing the dust cover when playing records sounded better than leaving it on. I suppose air born vibration could cause the cover to vibrate and transfer that to the plinth.

My first turntable (a pioneer something or other - nothing real special) had a dust cover that vibrated real bad whenever a train passed by my apt. Trains passed every 5 to 10 minutes of course everything in the apt vibrated real bad - did you ever see a refridgerator walk across the floor - sort of like a washing machine with a very unbalanced load. Anyway, I placed a sandbag on top of the dust cover (about 8 oz). Worked great for the dust cover, but the fridge still went on walkabout.