A Copernican View of the Turntable System

To all of you plinth-less persons, it is possible and permissible to do something different from what Raul does and still get satisfactory results. Think outside Raul's box. The AT616 feet may be good, but they cannot possibly be the only "good" option for feet. Also, I wonder what you are all using for platter mats. I found the stock rubber mat supplied with my SP10 Mk2A was easily bested by an SAEC SS300 metal mat (purchased from Raul, by the way), and I am sure other mats would also be superior to the rubber. One that I aim to try on my Mk3 is a Boston Audio Mat2. The Mat2 has about the same weight as the stock rubber mat and so should have no deleterious effect on function of the servo mechanism. (I don't recommend a super heavy mat for that reason.) My experience tells me that the stock rubber mat may be responsible for the the closed-in, grayish, dull tonal quality that some have ascribed to direct-drive turntables. (I have seen each of these adjectives used; take your pick.) I even think that the stock mat may have more to do with the tone than does the plinth or lack of same.

Nandric: what Lewm said.

Lewm: As you can see from my system pics, my second arm is behind the tt and in from the left edge by about 4 inches. The pod was designed so that it could go partially underneath the tt's square top (that is crucial). The pivot to spindle distance is 230mm and that's no problem.

Halcro: I'm not sure what you are imagining with the rocking, but I should say that I'm beginning to become suspicious of the ridigity of my system. I received my Mint protractor a few weeks back and it makes me appreciate the very fine adjustments required to maintain proper alignment. The 616 footers are great for isolation and leveling, but the contact between their smooth tops and the bottom of the tt's chassis is probably less secure than the ideal. To test this, I'm going to recheck alignment in another week. If it's off, I'll blame the footers. It may be an easy fix, just a matter of adding some blu-tac between footer and tt, but we'll see. The contact between bottoms of footers and platform is definitely secure as those suckers are not easy to move once settled.

Chris: indeed the footers' ability to be adjusted is key, otherwise leveling would be haphazard. Is the contact between the top of your footers and tt secure? I'll pm you regarding price; it's complicated.

Lewm: I haven't done any extensive comparative tests between the stock mat and my current one, the Boston Audio Mat 2, but the latter definitely lowers the noise floor. It's a deep dark black background--as it should be. One issue I've noted however is that the Mat 2 doesn't 'grip' onto records like the stock rubber mat. On certain records (warped ones), as I've applied a dust cloth to the record prior to play, the record will not rotate at the same speed as the platter, i.e. the downward pressure of the cloth is slowing the record's rotation. I infer that the record then is not properly coupled with the mat. This never happened with the rubber mat. Although not evident with flat records, it may be the case that this lack of coupling is having some effect with them as well. I ordered a ttweights record clamp and will see whether it makes a difference.

Regarding footers, obviously the AT 616 are not the only option. Who ever said they were? Chris was using brass footers before and as he said will use for his second set up. I was using the more readily available 605 footers before. But as he noted and I concur, there are practical advantages to using the 616's. In addition to what Chris noted, the 616's are 4" wide and that provides more stability than the 605's. Although I believe there are sonic advantages as well, no one thinking of going plithless should be deterred by the unavailability of the 616's. In fact, I considered using Eden Sound's terrastone footers but they probably require drilling holes into the chassis--something that I wanted to avoid.

Dear Nandric,
My DD/TT is a Victor TT-81 made for JVC ( and soon to be replaced by its scarce and finer brother.....the TT-101).
They have their bottom metal 'cage' attached (just as the SP10s have) so that spikes or 'footers' can be positioned under this 'cage'.
I find that placing the spikes under the vertical cage perimeter, results in the greater stability with no movement whatsoever in my particular case.

Noticed this thread when it started but didn't give it a read till today. Currently been condsidering a new plinth for a Garroard 301 so it was a great read although a plinthless 301 would not be a great idea but would be easy enough to try with a arm pod.

This thread and the debate within have change my direction some. A removable armboard or arm pod and the decision between the two has been the holdup for me. Over the past few days even before reading this thread I have decided to build multiple plinths for both while the table will be down.

May I recommend you guys take a look at

http://www.emachineshop.com/

Came across this service when noticed it mentioned in the DIY Schroeder thread, another great read BTW.

http://www.diyaudio.com/forums/analogue-source/13372-diy-schroeder-tonearm-11.html#post2242523

I have been using there software for awhile now although haven't had a chance to order anything from them yet. They have forum support and also video tutorials to help get started.

There is allots of benefits in using there software even if you have a local machinest already.

You could build a basic armpod in minutes then view it in 3D. Once comfortably with your design you click proceed/analyze and get any instant quote including shipping and weight!!! This alone make this software great. The site says this will work internationaly too.

Multple of the same design reduce the cost dramitcally, may be a great way to do a group buy. If you only want one item but think there may be interest of someone else that may want to purchase the same design you would order more than one to get the price for your one down then they will stock the remaining for a year. If they don't sell you would be obligated to pay for the remaining but if they do you would receive a percentage of the sale, how cool is that.

Another great feature of the sofware is you can import and export files. You can easily import a .dwg file to get you started if you have some cad designs. For you guys that use a local machinest I would think if you design the part then export it to a cad file it would save you some bucks since your machinest wouldn't have to create the design to enter into his CNC.

Brad