[Miney]

I’ve seen several mentions of plasti-clay in this circle… am considering employing it on my 9.9 lb. weakling (Technics SL-QD33).  But before doing so, I thought I’d ask the experts a few questions?

First, some photographic background. 

1.  The patient in action…



2.  Underneath the platter with the base tray removed:



3.  A side view of the TT standing on its dustcover… notice how some of the innards are protruding:



4.  And finally, the base tray itself… presumably where the plasti-clay would be implanted.  FYI, maximum depth is ½ inch:



Being a re-newbie to vinyl and definitely a newbie to tweaks, I’m looking for some wisdom before operating. 

Intuitively, I understand the value of adding weight and eliminating dead space.  But I don’t want to do more harm than good.  So I wonder...

How close to the electronics can I get?

How much clay will it hold?

Is clay the best solution for me?

How much a benefit should I expect?

Is there anything else I need to consider?


Sincere thanks in advance.

Paul

[TheChairGuy]

Paul,

Pretty slim in there - I'd estimate 5, maybe 6 lbs max.

Very little to no benefit in clay'ing your bottom tray....you need to clay your innards.  That is, your plinth underside.  reduce vibrational energies there is the goal.

If something still moves freely and you haven't applied it to the actual wiring, PC boards or other doo-dads inside...I'd estimate your looking at 5-6 lbs total in there.  Once you get started you kinda' find more ways to shove more in.

Believe me it helps.....4 TT's later I have experience on.  But, that's not a top-notch deck you have - so just don't expect miracles    But, it WILL improve...indeed it will.

John

[Miney]

Thanks very much John for the response ...  gives me what I need to proceed with more confidence.

Yeah, it's quite slim, and certainly not a high-end rig, but I'm really enjoying using it again.  I had planned to upgrade... after a lot of research, I contacted Kevin @ KABUSA to configure an SL-1210M5GSE.  After learning about my system, he indicated the SLQD-33 was actually a decent table, and I might not see a whole lot improvement in replacing it, adding that the money might be best spent on a new cartridge (and it did - big time).  Gotta say I really admire Kevin's candor, and understand why so many people recommend him so highly.

Anyhow, I'll be pursuing the implant surgery as time permits, and report back as to impressions.  Thanks again for the detailed insight!

Paul

[Miney]

John - another question on this ....  I'm wondering just how adhesive plasti-clay is.  Considering I need to turn the table upside down, stuff it into the plinth underside, and then I turn it back over -  it needs to stick to the underside -I don't think I want it falling and touching / stressing any wires or or other "doo-dads," as you say.

Ever hear of anyone trying silicone caulk?  I happen to have a few tubes of very good stuff (non-acetic, neutral curing - won't corrode metal) laying around.  Perhaps it is not as dense a material as plasti-clay, but it'd fill the cavities, and I could dole it out with some precision. 

Whadda ya think?

p.s. Just looked at a tube to see if it specified weight (not) - but it did state the caulk is "specifically formulated for use on vinyl products! Karma? 

[TheChairGuy]

John - another question on this ....  I'm wondering just how adhesive plasti-clay is.  Considering I need to turn the table upside down, stuff it into the plinth underside, and then I turn it back over -  it needs to stick to the underside -I don't think I want it falling and touching / stressing any wires or or other "doo-dads," as you say.

Ever hear of anyone trying silicone caulk?  I happen to have a few tubes of very good stuff (non-acetic, neutral curing - won't corrode metal) laying around.  Perhaps it is not as dense a material as plasti-clay, but it'd fill the cavities, and I could dole it out with some precision. 

Whadda ya think?

p.s. Just looked at a tube to see if it specified weight (not) - but it did state the caulk is "specifically formulated for use on vinyl products! Karma? 

You are thinking too much instead of doing...something I am guilty of as well from time to time 

If you screw up (highly, highly unlikely) you can probably replace the deck for $50 on ebay...so go for it. You'll get it right the second time, if for any reason you do.

The modeling clay semi-hardens once it is removed from it's plastic liner (each 'stick' is so covered with plastic inside it's box) and packed down inside your deck. It won't squirm loose under any circumstances (except perhaps a 9.0 earthquake  )

If you screw up with the tubed silicone caulk - it's much harder to remove.

Your current deck won't improve unless you improve it...and I know no better nor cost effective way to improve a plastic bodied deck than modelling clay stuffed and packed solidly in a decks gizzards 

John 

[AudioSoul]

    Most online  audio stores sell damping material in sheets they are'nt as heavy as clay but will damp
    the vibration. Plus it doesnt take up a lot of room. I would be afraid the putty would work loose and fall
    into moving parts. With that said it is worth experimenting but I would'nt expect fantastic results
    whether you use damping sheets or clay. Actually, I remember doing the clay thing years ago on a
   Denon DP 30 TT and it helped, but I ended up selling it and buying a better TT in the end......DK

[soewhatman]

On John's recommendation I packed the innards of a fully automatic Hitachi turntable with plasticlay.  The difference it made was not subtle. Like two different tables.  Being fully automatic and full of gizmos inside, I maintained about 1/2" clearance to all circuit boards, mechanical parts, and the motor.  I've been running mine like this for a number of months now with no problems.  I recently pulled off the bottom to adjust a potentiometer for the table speed and did a thorough inspection at that time.  None of the plasticlay had come off or moved into the way of any moving parts.  I don't foresee having any problems with this in the future.

Rick.

[TheChairGuy]

    Most online  audio stores sell damping material in sheets they are'nt as heavy as clay but will damp
    the vibration. Plus it doesnt take up a lot of room. I would be afraid the putty would work loose and fall
    into moving parts. With that said it is worth experimenting but I would'nt expect fantastic results
    whether you use damping sheets or clay. Actually, I remember doing the clay thing years ago on a
   Denon DP 30 TT and it helped, but I ended up selling it and buying a better TT in the end......DK

4 or 5 decks now done, either Plast-i-Clay or rope caulk putty (not recommended as it peels the skin from your hands after a while working with it) and it's never shaken free (you press it in a bit and it sticks nicely) in 20+ years.

I've used constrained layer damping sheets and EAR Isodamp sheets - and neither was as effective as the clay.  You need to use enough of it inside (generally 5-8 lbs in the innards of the Japanese direct and belt drives of the 70's and 80's).  One exception, of course, is the Technics SL-1200...which already (quite admirably) used layers of heavy rubber and aluminum composite in their base to reject feedback and reduce rumble that would normally travel to your stylus  aa

Using enough clay is a fantastically helpful tweek for any plastic bodied deck....I've even laid the clay on the top (visually scene) of the deck with tremendous further benefit.  But, it's ugly, REAL UGLY, there - unfortunately it works wonderfully to tame additional energy that poisons sonics 

Hey Rick - which model Hitachi (I liked the Uni-Torque series back in the late 70's) do you have and how many lbs of modelling clay did it take?

btw, I saw EZ Shape brand of modelling clay at my local (independently owned) Ben Franklin craft shop for $3.69 for 1.1 lbs.  It's a fantastically economical upgrade buying 8 lbs and about 2 hours of your time to really shove it in there tightly.

I bought a pack (white) and already added it to my DUAL 701 that just came in...even tho I specified an upgrade plinth ($90 extra) it was not much more than 3 lbs total to it and needed the bulking to improve the DUAL further.  It's an open bottom, so the amount I can use is somewhat restricted.

John

[Wayner]

The SL-1200 plinth is still die-cast aluminum and could benifit from some plasticlay. I plan on doing mine this weekend.

Wayner

[TheChairGuy]

The SL-1200 plinth is still die-cast aluminum and could benifit from some plasticlay. I plan on doing mine this weekend.

Wayner

Not much room at all in there for clay, buddy...I think I squeezed less than 1/2 lb in mine (max).  Seriously, the Matsushita guys really did their homework on that deck.

It's a serious piece of work for 500 clammers...if only my beaten-up example could shine 

John

[Wayner]

Because it's a die-casting, it's inside surface has "waffle" like pockets that invite plasticlay. It actually looks like the inside of my SL-Q2.



I will be care to stay away from the base and all internal components. Of course, I will post pictures as I'm doing the deed.

Wayner  aa

[TheChairGuy]

It's been about 5 months since I looked longingly at the Sl-1200 innards....but I seem to remember something quite different in my version.  Literally, the tri-ply sandwich of aluminum and rubber fit nearly perfectly with very little room to put plast-i-clay in it.

You have to open the whole deck up to put the new Origin Live tonearm board in...so I had that sucker open a few times in total.

Seriously, the Matsushita guys did their homework on the SL-1200 series.

Maybe your (much more recent) example is made differently...I kinda' doubt it as they wouldn't invest tooling in a model that only sells 80,000 units yearly 

Anyhow, let us/me know otherwise.

John

[Wayner]

The inside bottom of the plinth has a rubber-like cover on it, too. That will have to be removed also, then the insides will look similar to this. It has a lot of screws and is intimidating, but I've been in there.

Wayner

[Mike B.]

I use two products for dampening items like this. One is Blackhole pad which is adhesive backed and can be cut to fit those recessed areas. I also have a roll of 1/2" wide adhesive backed lead tape which  I purchased from McMaster Carr many years ago. I got the Blackhole pad from Michael Percy Audio

[soewhatman]

John-

My TT is a Hitachi HT-460.  Its not one of the quartz lock models, but it hold speed well enough that it sounds fine to me.  I think I put 7 lbs of plasticlay in mine.  I also re-built the base out of a block of 2" thick mahogany, and route it out in places to accommodate the working parts and motor.  The table weights almost 30 lbs now, and I'm quite pleased with it for a modest investment.

Rick.

[Miney]

Well, I finally got started... but not finished... it took me over an hour to stuff 2lbs into the bugger.  I'll try to insert the remaining 6 lbs. next weekend.

Got a question, Coach (John) ... do I hafta work around the wires, or can I put at least a coat under them or (even better) bury them?  Lotsa snaky stuff in the way...



Of course I'm talking only about the jacketed runs.  I'm already keeping 1/2" clearance around the boards and mechanicals.  Already pulled one of the boards up to apply a 1/4" of clay under it.

????

[avahifi]

Silicon seal is not a good choice for a damping material.

In keeping with my original 1982 Audio Basics article on the subject, the governing factor is that "meatballs don't bounce".  Silicon seal bounces, plasti-clay does not.

Also be wary of plumbing substitutes such as mortite, etc.  They may contain an acid bass that can corrode wiring.

Finally remember the misfortune of the newlyweds who confused Vaseline with mortite.  All their windows fell out.

Regards,

Frank Van Alstine

[Miney]

Silicon seal is not a good choice for a damping material.

In keeping with my original 1982 Audio Basics article on the subject, the governing factor is that "meatballs don't bounce".  Silicon seal bounces, plasti-clay does not.

Also be wary of plumbing substitutes such as mortite, etc.  They may contain an acid bass that can corrode wiring.

Finally remember the misfortune of the newlyweds who confused Vaseline with mortite.  All their windows fell out.

Regards,

Frank Van Alstine

Thanks Frank.  I abandoned the caulk idea.  Having now worked with it, the Plasti-clay is a much more workable solution as well.

No comment on the Vaseline... 

[TheChairGuy]

Jam it anywhere in there, Paul...so long as you don't cake it on moving parts and probably a good idea to let wiring continue to hand loosely.  Stick to the plastic areas...the metal areas (like the motor) may need area to breathe and release hot air...so you don't want to constrict that.

You probably can hear a difference with only the 2 lbs in there now.....I'm not sure you'll be able to jam in another 6 as your deck is kinda' slim, but I think 2-4 might be able to fit in there 

John

[Wayner]

Well a day off from work (floating holiday) and I've plasticlayed up the Technics SL-Q2. Of course my usual source for the clay changed brands and now it's colored modeling clay (non-drying). Works just the same just with 5 stupid colors.



Now when you tap the top plinth, you hear just a short dull thud. We'll give 'er a listen today out in the garage and see what it sounds like.

Wayner