Help in isolating a TT with spring suspension.


Hello,

I recently got an old Pioneer PL-10 TT at an estate sale. After cleaning it up and getting a new headshell and belt for it, it looks and sounds to be in NM condition.

It sounds great as long as you just sit there, but as soon as you start walking around, even softly with no shoes, etc., it causes the tonearm to skip around a bit. I replaced the rubber feet the springs rested on and leveled it, but it still vibrates when you walk.

Are these types of TT's normally this sensitive? I find this unacceptable. I'd like to keep this TT if I can eliminate this problem. It's original rubber feet are pretty hard and chintzy. Would getting some kind of cone feet help? It is resting on a vertical rack which isn't exactly audiophile quality, but isn't light weight junk either.

Any suggestions would be greatly appreciated, but please make them somewhat reasonable (no $900 Harmonix feet)!
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It's not about what you put under it, but about what you put it on ;-) And even if your "rack" is reasonably sturdy, the floor structure under the rack is probably what's bouncing (it's not a concrete slab is it!)

I bet even an un-sprung TT would have trouble in that situation, and what you're going to need is a wall shelf for the TT. Target's shelf ($179 at AudioAdvisor) is probably the most popular, and you can see it here http://www.audioadvisor.com/products.asp?dept=214

IMO, even the best TT stand sitting on a concrete slab can't beat a PROPERLY MOUNTED wall shelf.
It's not about what you put under it, but about what you put it on ;-) And even if your "rack" is reasonably sturdy, the floor structure under the rack is probably what's bouncing (it's not a concrete slab is it!)
Yes, I have an old house and my floors are not that good, but I've had other TT's that were not nearly this bad.

A wall mounted rack would be nice but it wouldn't work with the way my room is set up, and I really don't have the room for it. Speaking of concrete slabs, would putting a heavy flat piece of slate or stone of some kind help?

Thanks for the info.
It's not about what you put under it, but about what you put it on ;-) And even if your "rack" is reasonably sturdy, the floor structure under the rack is probably what's bouncing (it's not a concrete slab is it!)
Yes, I have an old house and my floors are not that good, but I've had other TT's that were not nearly this bad.

A wall mounted rack would be nice but I don't think it would work with the way my room is set up. Speaking of concrete slabs, would putting a heavy flat piece of slate or stone of some kind help?

Thanks for the info.
Drill a hole in the cieling and put a large heavy flywheel on a bearing that will accept a cast titanium rod that has a braek away split tackle ring in it. Put the record on platter then jack up the stand until you can attach the free to rotate, superstrong, titanium rod and flywhell. The super upstairs flywheel rests on a track which is a semi enclused u channel follied with very lightwieght oil . Cordinate a 1 hp electrical motor to drive that wheel in synchrony from the platters own small motor. Have the rack decouple from the flor though vibration isloation industrial grommets make sure all is on a laser leveled angle, taking absolute pendulum striaght fall 0 = the table flywheel assembly as your reference and you are ready to go.
Or just place your current rack on a very heavy steel reiforced thick wooden walled sandbox put an attractive wooden slab as the top layer and you could even get some real massive spikes for rack footers. This mass will abate your footfall and will not allow spinged tension to release put the box on a 3m cork mat with neoprene then a layer of sorbothan sheet then another layer of cork neoprene . Although not fashoinable there is dust free lead micro shot available to fill the sandbox that's the sand and what I mean by mass. Make sur you get the ordinances licenses and an architect to sign of on iether choice.
Add up the cost and realize the shelf is much much cheaper and as effective. With your savings buy a really nice table and get into vinyl.
Or you could try an Arcici Airhead. I had one under my Weel Tempered Reference for many years and it worked well. Basically it is a wooden platform floated on three inner tubes.
Check or increase your tracking weight.
Chris, if you can't do a wall shelf, you have only one alternative and that's to secure the floor. The easiest way to do that is to put two or four posts (depending on the joist spacing) in the crawl space to support the floor joists right under where the rack sits (so that the floor won't bounce, at least in that area!) You need to go into the crawl space and use some (rented) jacks to jack up the floor joists an inch or two, and then slip in some 4x4 posts under the joists (set on those little pre-cast concrete piers so the posts won't rot ;-) It's simpler than it sounds and works like a charm.

Setting something heavy like slate or stone on a floor that already bounces won't help.
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I had a Brightstar inflatable platform and found it needed shifting.Was good under digital.But some folks build them wood box and inner tube (which Brightstar is).I think that if it's that bad wall mount or get out of table hate to say.But I like the Frankenstein Lab idea that Mechans came up with.
Chazz
Depends on how flexible and creaky your floor really is. If you locate the shelving against a support wall of your house, that will mitigate the problem to some degree. After that I suggest a heavy hardwood shelf to go between your existing shelf and your tt. Between the hardwood slab and the support shelf, you might try springs that are available very cheaply from McMaster Carr on the internet. Select the springs based on the combined mass of the upper hardwood shelf and your tt. Dave Garretson has used these springs very effectively. You might search for his posts here and on Vinyl Asylum, under DGarretson. The other suggestions offered above might work but seem to me to be very expensive and time consuming.
Have you verified (with a gauge)that the stylus is at the correct tracking force? If your table uses a "spring" anti-skating system, has its proper functioning been checked?
I don't know this turntable, so this response may not apply. I take it the platter is suspended. You say you've had other turntables that were not that bad. Were they suspension tables? If so, the springs on this table may account for the difference. To the extent that they are adjustable, you could try putting more weight on the platter and increasing the tension on the springs to get less bounce. You could experiment with, for example, a small vase that might weigh two or three pounds. Center it mouth down over the spindle to see how the turntable reacts to the weight. If you can get the platter at the right height, then you might want to consider buying a weight or clamp, or a heavier mat, or even a ring, or some combination of these. Any of these might also improve the sound, and the ring does help to flatten any small warps.
Have you verified (with a gauge)that the stylus is at the correct tracking force? If your table uses a "spring" anti-skating system, has its proper functioning been checked?
The cartridge on the TT was professionally installed. It tracks light at 1.5 grams so increasing it a little might help slightly but the whole plinth jiggles and shakes when walking in the room so the problem is bigger than that.
Chris,
I understand your frustration. I've been there.
I believe that you have 2 choices.
First, use a different turntable. Secondly,
look at the problem from a different perspective ( somehow make it work in the room)
and find a way to utilize one of Nsgarch's suggestions.
Chris,
I understand your frustration. I've been there.
I believe that you have 2 choices.
First, use a different turntable. Secondly,
look at the problem from a different perspective ( somehow make it work in the room)
and find a way to utilize one of Nsgarch's suggestions.
Thanks for the help. I will use this TT temporarily until I can get the one I want (that I know wont shake like this one). I only paid $50 total for it including belt, headshell, etc.

I can understand why many TT manufacturers don't utilize this design. It only works if you have perfect floors, and it's difficult to fix and level when it gets old.
What cartridge are you using?

A poor cartridge/tonearm can add to your problems. A high mass arm and high compliance cartridge can put the resonant frequency of the cartridge and arm exactly in the range of the nearby footfalls, which are typically at 7 Hz or below.

The solution is to use a less compliant cartridge. Typically, high output moving coils have lower compliance than moving magnets, so a cartridge like the Dynavector 10X5, Ortofon X5-MC, or Denon DL-160 would help your situation. (I'm not sure of the Denon's compliance at 7-12 HZ, which is the area of interest for footfalls).

Another suggestion is to brace your stand against the wall. I used a couple pieces of closed foam cell wedged between the wall and the stand. The point is to put some of the weight of the stand against the wall, which is presumably not subject to the footfalls.

I had a TD125 with RB300 and changing cartridge to Ortofon X5-MC and bracing the stand made the problem tolerable. A remodeling project to remove the carpet and replace with wood floors eliminated the problem completely.

You can also try stuffing cotton balls in the turntable springs to see if that might help.

Good luck!

Hi Chris,

I live in a 80yr old house, with creaky wood floors. I have had very good luck with using clean, "sandbox" sand (like you get at Lowe's) placed in 4 quart sized ziplock baggies, sandwiched between 2 3-4mm thick squares of cork.

I can't say it looks real pretty, but it is very effective.

Hope this helps :)