A Copernican View of the Turntable System


Once again this site rejects my long posting so I need to post it via this link to my 'Systems' page
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Mass loading is very good – at least that is what my ears are telling me.

Version one aluminum armpod was only a few lbs lighter than the brass - but the weight was dispersed over a longer armboard. The increased force provided by the brass is a positive thing that can be heard. I am not going to provide a lovely description like Dgob provided us with. Let’s just say last weekend I found myself reaching for more lps – some I had not heard in a while – if this is not positive behavior for this hobby I don’t know what is.

Recommendations.

How high is your platter? The higher the platter the more material you will be able to use to get more weight (either a bigger diameter or higher armpod). I have the AT 616’s adjusted now to their highest point – and my tonearm is adjusted to its lowest point. Any higher and it will not work in my setup. I came close and actually had fears when I brought the brass home that I had miscalculated. After analyzing - I breathed a sigh of relief - thank u Bruce Thigpen for all the adjustments u put on that ET arm :)

Symposium Jrs.

With that a source came through and I now have symposium jrs. on their way to me. I understand that they are 1 ½ inches high so my current armpod will not be able to be used for this experiment - as stated my tonearm is set at its lowest adjustment. If anyone can suggest a way of doing this without propping another layer under the sp10 let me know.

So I will get another armpod made a lower one for this - probably about 3 inches high and maybe try it out on my 12" pivot arm as well. I had plans for another armpod anyways

Cheers Chris
Hey Chris,
You can always elevate your turntable by putting some big tall feet under it, to enable you to use a more massive pod. How about that Vyger turntable? The pod would be 4 feet high or so, judging from photos. In brass, that would be significant mass, I'd say.

You made me think of this, because I have just recently elevated my Lenco in its slate plinth, not so I could use a massive arm pod but in order to accommodate some "feet" that I made out of cans of Mandarin Orange slices in water, sitting on tiptoes. In my rationale, the closed system of Orange slices floating in water helps to dissipate energy (by sloshing of the water damped by orange slices) going from the floor up into the shelf and hence into the slate. For $6 plus the tiptoes, which I had on hand already, it "works a treat", as the Brits like to say, and if you don't like it you can eat the Mandarin Orange slices, for another kind of treat.
Lewn - I disagree - I think that cantaloupe slices would work better than the orange as they are not as acidic, they are in season right now, and studies have shown when talking to workers from their place of origin that they resonate the least : >)

I am having a hoot with this and looking forward to making another arm pod for my other pivot arm and also testing out the jrs on alternate equipment first.

Just a short follow up on my experience with the footers used under the platter/motor.

First I believe it is more important that you have a good solid level isolated platform. I dont think footers should be used as a bandaid for fix platform problems. Fix the platform first.

I have experimented with footers 1) when necessary to up hold a DIY project like this or 2) to change the sound of manufacturers feet.

This applies to one above.

I tried different feet and they all worked. I would still be using the maple shade heavy footers but the at616 came along and they are adjustable. That was my only reason with the different armpods. Its very subjective – we all have different gear and even more different - stands and shelves holding the gear. Experiment with them.

As to weight of the armpod – I don’t know how much weight will work best. My footprint weight changed substantially with the brass - and I believe for the better – it certainly did not get worse – common sense says more is better – but as Lewn pointed out with Vyger some people get carried away. At least I think so. If you have ever picked up 10 lbs of steel or brass with one hand it is substantial – its not going anywhere when coupled with spikes. The next armpod for my other tonearm will again be out of brass, slightly shorter (to accomodate a test witht the jrs. eventually) and will cost $116.
Some people spend this much on an lp :).
Cantaloupe? Where do you ever see canned cantaloupe? I toyed with the idea of stewed tomatoes, peas, corn, etc. Anything that is sloshing around but has some substance. Cantaloupe might work if the water content is high enough. Note that I am taking your response seriously. Not.

Soon I will mount photos of my anti-no-plinth, made to my design and then assembled by me for my SP10 Mk3, using a huge slab of slate bolted to a substantial wood base made from solid cherry and baltic birch and with a brass billet imbedded under the table to dampen any bearing vibrations via connection of the bearing housing to a brass rod which screws into the brass billet, a la the Albert Porter idea. It weighs about 90 lbs without the SP10 installed. The wood base really adds substantial further dampening to the slate. You guys would hate it.