Turntable Shelf

[dcarlson]

I made a trip the Home Depot and picked up a couple of wall brackets and a piece of 1/2 inch plywood laminate. My plan is to cut a piece of plywood 22" wide and 17" deep. That will give me 2 inches all around to play with once I have the TT on it. I will proably cut a whole in middle for easy access of the shelf which may be about 14' wide, my TT is 17" wide. The wall brackets are supposed to hold upto 100 pounds if mounted to the wall studs.

Am I missing anything?

[RuSsMaN]

Isolation! What are you going to use to damp bad vibes?

[organ]

That sounds great Derick. I'd make my own rack if I could but don't have any wood working skills.

Russman suggested that you need some damponig but if the wall you're planning to use doesn't vibrate much I don't think you'll have any problem.

If it vibrates, the only thing I could think of is using two pieces of plywood and have two soft mouse pads glued between the two plywood. You can also use one mousepad cut into four pieces and place them on the corners. Let us know how it turns out.


good luck

Maurice

[dorokusai]

Try using Dynamat for the back of the brackets and the bottom of the shelf. You can use it anywhere that it won't be seen, it has graphx on it or a silver film. I used this for my speakers and it worked very well for resonance on my mounting wall.

www.dynamat.com

[dcarlson]

I'm starting to realize that vinyl is pretty sensitive. With my new wood floors, I have to tip toe the TT so it won't skip. I think I can hear some bass amplification from the vibration from my entertainment unit. When I touch the TT I can feel the chassis vibrating.

Maurice, you've gotta get a cart for that TT. I like what I hear already and I know it can get a lot better.

That's a cool idea. Everything is all wood so, I could use the Dynamat and throw some molding around to hide it.

Thanks guys, you're always help.

Keep in mind, I'm just getting into vinyl. I'll be giving you guys my impressions after every tweak and upgrade. Should be fun.

[burdette]

Just an idea....

When I went to college in '83, obviously vinyl was still going strong.

In the dorm, I screwed four hooks into the ceiling. I hung a quality twine from each hook down to about chin level, put moderately stiff springs on the end of each rope, then attached a wooded shelf to the rope/springs.

We didn't have any problems with isolation. And it looked pretty cool.

[dorokusai]

Burdette - That sounds really cool. I would like to get a TT in the future, just so I can check out some vinyl.

[dcarlson]

I would be a little concerned about it swaying.

[madmax]

Just a thought here. Dump that noisey laminate wood and get a couple pieces of MDF board. You could glue a few pieces together to make it even thicker (maybe 3" thick) and the added mass may help you out because the resonance of the piece will be very low in frequency. Also, I notice that the walls do not move with the floor. You should be able to get a sumo wrestler to jump up and down beside it without a hitch!

madmax

[dcarlson]

Thanks for the thought, I'll be cutting a nice big hole in the bottom so I think the resonating will be minimal.

[madmax]

Enough mass to dampen the horizontal wall movement and lower the res freq would be nice. From what I hear a lot of audiophiles like a particular cheap table from Ikea because it has a high mass top and spindly legs. Not really an option for wall mounting though. I looked it up at one point and it was about $60. Unfortunatly I can't remember the name of it. I guess if it doesn't cause a feedback or rumble problem it doesn't really matter anyway.
madmax

[dorokusai]

I think its called the flurble....or the kinklefarg....no wait its the burbletuuf....I can't remember either :)

[dcarlson]

Funny, I've heard of that table being good too. Don't know the name either. :)

[madmax]

I finally got a table saw last month and I've been thinking a lot about building something to sit my tt on. Sounded simple until I started trying to figure out what I wanted it to do. Might be a good first project for me as I'm sure I will have to redo it a few times before it looks good (not many woodworking skills) and sounds good. I was looking at the VW-1 wall mount shelf but it is expensive and too small anyway. It might be worth looking at from a design standpoint though. Now I'm trying to think where I saw it. I think it was on amusicdirect.com
madmax

[Tour2ma]

dc,

Best isolation is the next room. It's a good idea for any source, but especially so for vinyl. And since vinyl requires extra legwork anyway, a few extra feet of travel won't matter.

I'd avoid the wall mount... too much area exposed and the walls are not that stiff either.

The ceiling suspension is workable, but leveling the platter is difficult. I once saw a demo with a TT suspended from the ceiling (Garrard I think)... upside down. Record clamp and "reverse" balancing of the tone arm are all that are needed. No benefit except a high "cool factor"...

[dcarlson]

Another room? Whoa. ;)

I think my entertainmen unit is really hurting the quality for me. The best I can do is mount it close to the edge of the wall that's not a corner.

Right now, if I play some vinyl and turn up my new baby past 1/2 I get some bad bass feedback.

[madmax]

Originally posted by dcarlson
Another room? Whoa. ;)



Right now, if I play some vinyl and turn up my new baby past 1/2 I get some bad bass feedback.

A good quality table took care of this for me. At this point I can sit my table in front of the speker and it performs without these problems at very high bass levels. So what took care of this problem? I'm not absolutely sure but I think a few things helped. A clamp on the spindle now holds my lp solidly so it cannot vibrate, the platter is a high mass version which in conjuntion with the clamp causes my lp to appear to the tone arm to be the same mass as the whole assembly and a high mass object to sit the table on allows a disapation of these vibrations into the object rather than vibrating the platter. Starting to make sense at this point?
madmax

EDIT: Try moving the table from between the speakers if that is where you have it. Even if all else is not perfect this sometimes helps. I used to think this was an obvious condition for turntables to experience (the feedback) but it isn't.

[dcarlson]

Makes sense to me.

Another reason I was going to shelf mount is for easy access to the underneath of the TT so I can easily adjust the suspension height. I have suspicion my subchassis isn't adjusted properly. It's a pain in the ass to get under it, adjust, check. Now, with my new integrated, the phono stage is a lot better and it's revealing a lot more. I haven't had a chance to fiddle with the TT yet since the new purchase friday. I'll do that tonight, maybe and let you know. Thanks for the input.

[dcarlson]

I adjusted the suspension on the TT and it helped. Now, I'll only get the bass feedback when I turn my amp up to 3/4 full volume. Which is way loud.

[madmax]

That should be close to good enough. Reading your other post about the integrated, I was wondering if it has a decent rumble filter? A lot of them mask too much sound but some seem to work ok. Mine removes too much.
madmax

[dcarlson]

I wouldn't know the difference yet.

[tryrrthg]

here is a DIY sand filled isolation platform that I plan to build some day for my CD player. Can't be too hard or expensive to make. It's gotta be worth a try...

TNT Isolation Platform (http://www.tnt-audio.com/clinica/sandblaster_e.html)

[madmax]

I can see it now, a kitty litter pan filled with sand. And why would your kitty not want to make it his favorite place?

It wont be long before you hear the differences and become very critical. That is what's so cool about mechanical analog. Everything changes the sound!

But seriously the sand idea has been on my list for quite some time as well. I had never seen this article but had seen the "big rock little something" in some magazine. Same idea. I wonder if it would be benificial to build this idea into a wall mount? Sounds interesting.

I wonder why you have to have river sand, not beach sand???
madmax

[dcarlson]

Good link, thanks.

Definitely something I'll keep in mind for the future. I may need to start buying some power tools to do all of this stuff.

[tryrrthg]

Originally posted by madmax001
I wonder why you have to have river sand, not beach sand???
madmax

I'm not sure. maybe river sand is denser than beach sand, not to say that beach sand is dumb... ha ha, yeah that was bad!

Thanks, I'll be here all week! :D

[dcarlson]

It's ideal to get the heaviest, densest materials as possible to place the TT on to minimize any transfer of vibration? I'm starting to get the idea... Would marble be the densest material for a platform?

I'm still going to try the wood shelf, it should make a difference, at least in terms of walking up to the TT without having to tip toe there and then tip toe back to my chair. That really sucks, and I'm finding I'm tip toeing from my CD player, doh.

[madmax]

Originally posted by dcarlson
It's ideal to get the heaviest, densest materials as possible to place the TT on to minimize any transfer of vibration? I'm starting to get the idea... Would marble be the densest material for a platform?




You know, that is the same exact question I asked when I was trying to figure it out. NO! was the answer. Something about being too hard or something if I remember correctly. It's a strange audio world out there.

There was some talk about what you are looking for it to do. I'm getting into guesses here because I don't fully understand but it goes something like this. Lets say your motor vibrates (as it does) and you want to get rid of that vibration. You would have to transfer that vibration to something too heavy to vibrate. If you transfer it to something too light it will also vibrate. But... maybe another problem is coming from the outside (like maybe feedback) in which case you want to isolate the whole assembly. If you isolate it you still need something heavy enough to tame the motor vibrations so something like a mass sitting on some rubber with the turntable spiked to the mass. Damn it is so confusing but the more you think about what your possible problems are the easier it is. The main hurdle for me was to really take enough time to look at it rather than just deciding what is best without thinking. What really got me thinking about all this is the fact that they sell isolation pods to fully isolate and yet they sell spikes to tranfer. Not only that but then they get into vertical and horizontal isolation. One device I looked at was a metal ball between two metal cups. This provides vertical transfer but horizontal isolation. Think about that one. Whew... Sorry to go on but I've been thinking a lot about this lately. I need a social life or something.

madmax

[dcarlson]

Jesus... I think I got ya. Now, I have to really think about this. Hmmmm, takes me back to high school physics. :D

I've never really looked into pods yet, I think I should. I didn't realize some would isolate and some would transfer. Cool.

[dcarlson]

BTW, what ever happened to RLW? I know asked a while back, then emailed him.

[madmax]

I don't know but I wish he would continue to post. He is the one who got me into all this mess. :D
madmax