I agree with geoff, and I don't like how squishy it is, also Sorbothane leaves residue and a stain that is hard to remove from surfaces.
I have found Herbie's products far more effective and easy to work with.
Infection - Not sure anybody's actually ever employed a "Mag Lev" solution. Found an online forum discussion on the subject and curiously some contributors recommended sorbothane feet http://forum.polkaudio.com/discussion/139293/part-1-maglev-tt-stand-part-2-vibration-isolation-devic....
My listening room floor is suspended above a crawl space, so it's pretty bouncy. I haven't tried stomping around while a record is in play because I'm honestly afraid to learn what might happen. Hence my foray into sorbothane isolation, which I did not mention previously because I was preoccupied with the potential sonic implications.
Whoa! As far as I can tell the Mag Lev thread doesn’t actualy talk about magnetic levitation, just a lot of extraneous stuff. Oh, well. Obviously Mag Lev has been around like forever for turntables. Exhibit A - Verdier turntable. The Relaxa, which was mildly effective, was the name of the Mag Lev stand they couldn’t come up with in that thread.
I have used 1/2" sorbothane feet in addition to a layer of dynamat on the bottom of an external preamp power supply. The power supply was getting resonance interference from vibrations of my studio monitors and causing electrical resonance on certain notes which carried through to the audio. The sorbothane and dynamat successfully removed this resonance.
I have also used 1/8" sheet of sorbothane as a vibration damper on a home theater processor. You may have to use special adhesive because sorbothane won't really stick upside-down. Using a multi-meter I found that sorbothane does carry an electrical current, so be careful not to apply to any wire or pin contacts. The backing of dynamat and similar products also carry electrical current. Dynamat is excellent for applying upside-down and it is designed to operate in a high heat environment.
oh, another thing to note is that sorbothane is available in multiple durometers. A softness of 30A, for example, is so soft that it sticks to the surface and can mis-shape very easily. Using a higher 40A or 50A will help with deformaties, but it won't absorb as much vibration (still excellent though).
Here's some 50 duro 1" feet. I don't know what you're using.
I have some old school Audioquest Sorbothane Feet (the large ones), 8 of them that I've had for years. They are squishy and do leave stains that are very hard to get rid of, especially if you stack one component on top of another - a no-no but sometimes you gotta do what you gotta do......
Never knew they came in different levels of firmness. I just set them and forget them. I guess they make some difference but its more like piece of mind than anything else.
For a turntable, I'd use points, not sorbothane feet - the points are much better. Anyone remember the Mod Squad Tip Toes? Those were the best and only $7 a piece!
Wall mount is ideal. that said I had a discussion open a couple months ago and got many ideas. and not one was sorbothane. there is many better solutions out there. google isolation feet. but from what I tested a solid pinpoint on hard surface worked best under my Garrard. mind you that will not take out the larger vibrations like moving floors ie, foot falls and building movement, that’s why wall mount is the best. I found after testing the soft feet made the sound mushy sort of the hard pinpoints made the sound more focused and the detail better. hope that helps.
AVDesigns - According to the literature on your turntable, they say:
"Viso-elastic cones separate the platforms and act as superb dampening devices. The result: Quieter, more detailed playback that benefits from advanced vibration control, dynamic balances, and properly alignment of key components."
Granted, that's the description for the 5.1, but the MMF5 has the same thing.
Are you sure that you need additional isolation?
You might try felt bottom footers for your table's feet. Another option would be a separate plinth under your table that you could isolate independently and then level your table in the usual way. I have mine on 3/4" acrylic with isolation spikes - works well and even looks good.
I'm sure that you'll come up with something that ultimately works for you.
That link was just an example. See this:
They do have a variety of different sizes and durometer values for sorbothane feet. However, I don't know what is best for a turntable. These look interesting for 1.5"
And I can't tell you what the optimum durometer would be for your situation. Maybe the above 50 Duro 1.5" washers with cone spikes underneath?
avdesigns - You might consider starting a new thread in the analog forum for feedback from members with more experience with your particular turntable - but given that you can't hear any difference with the sorbothane pads, I will say this:
If you want to tweak and try different things, that's great as long as you enjoy it - that's part of the fun - but be careful and realize that upgrades and tweaking can become a slippery slope and I've seen many here spend more in "upgrades" than on the actual device they're trying to upgrade (with cables, isolation platforms, platters, weights, etc. etc.)
The fact that you can't hear ay difference with the new sorbothane is a good sign- shows that you aren't all that susceptible to "wishful thinking" -that's a good thing.
You have a great table for the money, you should enjoy it and if you see a problem and you can fix it? Go for it - otherwise, don't go chasing your tail unnecessarily - your Music Hall should deliver great results as-is and if you think that you have isolation or resonance problems, chances are, the solutions aren't going to ever be solved by some silver bullet "tweak".
Just my $.02
Sorbothane is a material like any other, and it must be used in the right place in the right way. That means engineering calculations. The sorbothane website is a good place to start.
IMO, feet are not the right place. Spikes give much better performance in both the TT which form my testbeds - sound is more focussed and precise, while sorbothane feet sound mushy.
Where sorbothane shines is in motor isolation. But again, it's not often used correctly. According to the website, you need inches of low durometer material to isolate the typical AC TT motor. That describes my DIY units - but not many others. Of course, there are other valid approaches, like SME.
The key here is how much noise is transmitted into the TT plinth from the floor. If you live in a railroad switch yard, you will need as much isolation as you can get. The SME solution is made for you. IMO. If you live on rock, miles from the nearest industry, highway or railway, you probably don't need any isolation at all. The latter is my situation, which is why spikes without any isolation device work for me.
As noted, YMMV.
Thanks lads, you have given me so much to consider. Far more than I anticipated actually, and I know there must be so much more to learn. I'm above all else a music and movie lover and although I'm notorioisly frugal (my mum says "cheap" lol) I maintain 5 entertainment systems and I'm willing to spend $ where and when I have to. I've just purchased a 40-yr old home, so trying to get everything setup to the point of perhaps preempting an unpleasant experience. So far, my experience has been all positive, apart for some concern over my bouncy floor. If one of these suggestions proves to be a winning solution I will revisit the topic to share that experience. Thanks, once agan. Cheers!
Timely tip: generally speaking you will get more traction by abandoning soft, pliant materials in favor of real isolation, I.e., mass-on-spring techniques, with minimal internal damping, using very stiff and hard materials such as diamond hardness ceramics to interface to both the top plate and directly to the floor, plus thick granite, maple or bluestone slabs for the top plate.
I bought a McIntosh MX130 preamp here on Audiogon several years ago. It had an audible hum that was not heard through the speakers. Someone on this forum suggested using sorbothane feet to reduce the hum. I did, and it worked! I also loosened the screws on the sides slightly and the hum completely disappeared.
Did you say '40-year-old home'? I don't recall the exact dates, but it was around that time that aluminum wiring was used instead of copper. This was a terrible idea because aluminum is a little hard to terminate, and poor workmanship resulted in fires.
You might want to consider checking the wiring. Your best audio investment may be in improved wiring - copper or copper, one size heavier than code (code usually specifies 14 AWG for a circuit, so use 12 AWG for audio circuits, and industrial quality sockets). I use a subpanel on the other side of the house, fed by a fat 2 AWG cable, which powers isolation transformers for the audio.
AV, you said you were frugal, so I mention that in some jurisdictions, it is perfectly legal for a homeowner to do his own wiring. Just make sure that you memorize the relevant sections of the applicable electric code, hire a good electrician to walk you through the first day, and make certain that every circuit is inspected before you energize.
Never work on a live circuit. Check with a multimeter, every time. Don't work alone.
Please follow the law exactly here - no shortcuts. It protects you and yours from a hundred horsepower hidden behind the walls. You will need rubber soled shoes, assorted screwdrivers, pliers, wire stripper, and a decent multimeter, like a less expensive Fluke.
Terry9 - I'm frugal but also risk averse, so I always hire professionals. The wiring was mostly addressed during the home inspection & was the responsibility of the seller (the original honeowner). But her contractor could not "see" everything, so my contractor uncovered additional issues, which he resolved (more or less). Still other issues remain to be addressed.
Hello Dent. I used a sticky, jelly stuff known as 'MOONGEL Damper Pads'. It comes in thin strips about 1" x 1.5", and is mainly used to tune drum kits by changing the resonance patterns.
Pieces on the Tomahawk wand above the cartridge, and at several points along the wand, work wonders. A few pieces on the saddle also help. The sound becomes more focussed and precise, but at the expense of some sweetness. This can be corrected electronically by changing the dielectric on RIAA capacitors, especially if you are using teflon, or by a marginal increase in the RIAA values.
I have a set of old heavy duty Sorbothane feet under my tube amp…these aren't as nearly squishy as Vibrapods which I use elsewhere. The residue is no biggie for me, and the heavier Vibrapods in use under my speakers work very well in decoupling them from my wood floor…highly recommended. I have some "real special" metal alloy cones under my preamp mostly because they keep air circulating under it, and because I discovered them in a box of old audio stuff and thought hey…those look pretty cool, and make me seem like I give a crap.
Just discovered something important, in case you are really looking at sorbothane. I looked up my order history and found out I got the 50 duro sorbothane feet. They are only 1" domes:
These really compressed and deformed under my power supply (which is not as heavy as a turntable!!). I figured you'd want to know. Probably best to try to get a 70 duro if you get sorbothane..
I'm sure there are better ways to go.
Geoffkait - I'm embarrassed to admit I'd never before known anything about J. C. Verdier Turntables. This collection of user experiences has been a tremendously illuminating read:
if your looking for inexpensive ways to isolate id suggest a talk with your local head stone maker ( possibly counter top maker as well) and get a granite / marble etc slab semi ruff cut its smooth but not shiny see the one under my table in my profile ( its bigger then you need at 3"x24"x18" and 165lbs but you get the idea). it cost me $60. then make a simple braced wall mount for it and you will be shocked at how much better it will sound. shouldn't cost much more then $150 total with a little leg work and simple fab work. if you want more details let me know. then get some cones/ pin points like others suggested and boom your in turntable glory.
or buy a turntable wall mounting kit and be done with it.
oh yes I used to have that 165lb slab on a wall mount...can't unfortunately in this place i'm in now though. I had that big slab in a corner though so got extra bracing there, all on some 1.5"x0.5" wood slats. It looked great by the way. i'll have to dig up a pic someday.