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Why didn't I think of this before? (SL-1200 footers)

beatcomber

beatcomber

AK Member
The stock footers on SL-1200s are well known for offering poor isolation against airborne vibration, which is why KAB, for example, offers Isonoe footers for $175.

My own solution was to remove the stock footers altogether and replace them with racquetballs sliced in half. This is a very common and inexpensive DIY solution and one that I learned here on good ol' AK. Additionally, the table was placed on top of a 3" thick cement patio tile, which itself is supported by four racquetball halves.

The cement tile platform combined with the racquetballs was very effective, but I was never satisfied with the appearance of the SL-1200 without a set of proper footers, but at present I can't afford $175 for the KAB isonoe set.

Tonight I got a brainstorm! I dug up the original stock footers and rolled up thin slivers of BlueTak, and wrapped them around the bottom of the threaded screws on the footers. When the footers are attached to the table, the BlueStik forms a seal between the bottom of the plinth and the top of the footer, which I was hoping would act as a vibration damper.

It worked! The BlueStik, combined with the inert, heavy turntable platform (the patio tile), worked like a charm! The amount of feedback I heard was comparable to when it had the racquetball footers, ie: barely any! It sure looks a heckuva lot better now too.

Why didn't I think of this before? :tresbon:
 
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I havn't had any issues with airborne vibration useing the stock Technics feet, the table is mounted on a large Target wall shelf and the heavy/solid Technics plinth also seems to help in damping any airborne vibration that might reach the turntable.
 
If I put my hand on the wooden table that I have my 1200 placed on, I can feel the surface vibrate. Not so the concrete tile. Every little bit helps!
 
I don't think I really need it but I'm considering installing a sandbox under the Technics, it should weigh a ton, well not quite but a lot.
 
majick47 said:
I havn't had any issues with airborne vibration useing the stock Technics feet, the table is mounted on a large Target wall shelf and the heavy/solid Technics plinth also seems to help in damping any airborne vibration that might reach the turntable.
Click to expand...

That's my experience as well, I also have the stock Technics feet. Perhaps at 'ear bleed' volume levels it may be an issue??? Not for normal listening though.
 
From what I have seen the SL-1200 and all the SP series (SL-1000/1015/1025) use the same basic Technics feet on the SH heavy Technics plinths so my guess is that they are more than adequate to ward off vibration. I'v observed SL-1200 turntables in clubs/discos where ear bleed volumes are the norm and if the turntables are mounted on solid stands the sound is clear as a bell. The SL-1200 didn't become the #1 club/disco turntable if it couldn't withstand the conditions that would rattle any other turntable.
 
I heard terrible feedback at moderate volume until I added the stone tile under the table. The stock feet are not very good at vibration isolation. The tables needs to be on an isolated platform for best performance.
 
beatcomber said:
I heard terrible feedback at moderate volume until I added the stone tile under the table. The stock feet are not very good at vibration isolation. The tables needs to be on an isolated platform for best performance.
Click to expand...

Perhaps it's more an issue of how and where the turntable is situated?

My SL-1200 sits an very sturdy steel frame bench which is on a tile-over-concrete floor.
 
I remember one club I visited the volume was deafining with multiple 18" JBL subwoofers and horns shaking the whole place. It felt like you were standing next to the tracks as a freight train went by. Even at that volume level with huge airborne vibration the sound was steady and clear coming from the records being played on the Technics SL-1200Mk2s in the DJ booth.
 
cactuscowboy said:
Perhaps it's more an issue of how and where the turntable is situated?
Click to expand...

Yes, most definitely. The wooden cabinet I use has a thick maple top, but it apparently picks up a lot of sound vibrations (I can feel them with the palm of my hand), hence the concrete tile on top.
 
majick47 said:
I remember one club I visited the volume was deafining with multiple 18" JBL subwoofers and horns shaking the whole place. It felt like you were standing next to the tracks as a freight train went by. Even at that volume level with huge airborne vibration the sound was steady and clear coming from the records being played on the Technics SL-1200Mk2s in the DJ booth.
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Yeah, but can you really hear feedback in that situation? I mean, I only notice it during quiet passages or in between tracks on an LP.
 
I have SL1200MKII sitting on top of a glass shelf about 8 inches from the left speaker, most of the time I have the volume set at 60 (volume goes up to 90db), and not a hint of feedback.
My question to you is, does your receiver or preamp have a subsonic filter?



John
 
Beatcomber a photo of the 1200 and the general area in the room it's located might help answer why there is airborne vibration.
 
beatcomber said:
If I put my hand on the wooden table that I have my 1200 placed on, I can feel the surface vibrate. Not so the concrete tile. Every little bit helps!
Click to expand...

Given the fact that you can feel the vibrations, your setup may constitute the "perfect storm" for feedback, either acoustic or mechanical.

In simple terms, your system can be viewed as a collection of spring/mass systems, in which one or more of the spring/mass systems is allowing enough of the audio output to reach your audio input (turntable) and cause feedback.

Your tweak interrupted this energy (audio output) and improved the operation of your system.

As long as it works to your satisfaction, you are good to go as they say.

Every situation is somewhat different and what is true for one may or may not be true for others.

You might be interested in further research to determine whether the energy that is causing your tabletop to vibrate is acoustic energy or mechanical energy, You might be able to reduce the overall vibration of your tabletop and further improve your sound quality.

This road to improvement can be somewhat addicting. Of course I can stop anytime I want to...:no:

Thanks for sharing your experience.
 
majick47 said:
Somethings wrong if you need a subsonic filter.
Click to expand...

I never said I needed a subsonic filter. I'm just trying to get the quietest, most noise-free performance possible. Y'know, tweaking it to perfection!

I'm just being picky since it was recently rewired and the arm damped, and therefore a lot more revealing of the good AND the bad.

JBL GUY said:
In simple terms, your system can be viewed as a collection of spring/mass systems, in which one or more of the spring/mass systems is allowing enough of the audio output to reach your audio input (turntable) and cause feedback.

Your tweak interrupted this energy (audio output) and improved the operation of your system.

As long as it works to your satisfaction, you are good to go as they say.

Every situation is somewhat different and what is true for one may or may not be true for others.
Click to expand...

Agreed!

You might be interested in further research to determine whether the energy that is causing your tabletop to vibrate is acoustic energy or mechanical energy, You might be able to reduce the overall vibration of your tabletop and further improve your sound quality.
Click to expand...

I don't think that mechanical energy is significantly affecting anything. The SL-1200MK2 runs pretty quietly.

This road to improvement can be somewhat addicting. Of course I can stop anytime I want to...:no:
Click to expand...

BINGO. But, hey, that's all part of the fun!
 
I'll soon find out if I need the subsonic filter or not, I have a rod Elliot preamp coming my way soon, lets see if my system is going to humm or feedback in anyway.
Because I am pretty confident that I am not getting feedback and the likes due to the PP2 having a active subsonic filter.

John
 
I haven't noticed a problem with my stock SL1200 set up. Obviously what you set the table on will have a lot to do with how well vibrations are damped.
 
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