Slate & acryl DD tt

[trondkj]

Hi folks, my first serious post here, hope you'll enjoy.

It began with a Dual 701 DD turntable, a nice turntable, but with an arm that is not up to the specs I wanted. The automatics were malfunctioning, so I slaughtered the tt and bought an acrylic platter from Diy Hifi Supply.



I was thinking about the plint, should I make a aluminium-ply-mdf-ply-aluminium sandwich like this:?



..or go for something different?



I went for something different, and since then I have done a lot of thinking, and a little work:


The acrylic platter on top of the slate plint illuminated by the midnight sun

Last easter i got a hole in the slate so that the EDS1000 motor would fit in.



Before that I had installed the power supply and speed selector / pitch control in a box:



The turntable with the motor and platter installed:



..and with a couple of arm boards temporarily placed on top:



I nice member of this forum saw the picture above on a Norwegian forum, and offered to make a couple of acrylic arm boards for me:



For this turntable the arm(s) have to be DIY as well, I am going for a Ladegaard tangential on the left arm board, and a 12" Schröder copy on the right arm board.

But I do not have enough patience to wait for the arms to be finished, so one of my temporar arm boards have to do as a base for my SME 3009/S2 Impr. for so long.



Not willing to make holes in the stone for the arm screen under the base, I had to do a little modification to the arm:



The left arm board is mounted to the stone with brass standoff/legs:



The right one is only standing on its legs, but they are shinyer than the other ones:



And of course there's something that simply does not fit in, and therefore has to go:



I am thinking about a motor cover made of black transparent acryl to replace this wooden thing.

The turntable plays with a Shure M75ED 2 with a Jico SAS needle to plow the grooves, and sounds really promishing.

Kind regards
Trond Kjetil

[bulgin]

Hi Trond

Really impressive design and solutions, as always. I am pleased someone else also considers acrylic as suitable material for turntables.

Regards

bulgin
(aka ol' blue)

[Iain McNeill]

That is some beautiful work, Trond. Everything has such eye-pleasing style and at the same time well-engineered.

I have been thinking of a similar project for some time but never got started. I would always think of too many problems and not enough solutions.

Are you using the bearings from the Dual 701? How did you mount the motor and bearing to the slate plinth? I'd love to see a few pic's of the underneath.

Great work & thanks for sharing!

[trondkj]

Thank you, bulgin and Iain

I am using the bearing from the 701, haven't even thought of using another. The motor/bearing (EDS1000) is of very good quality, and it has less of the typical "DD sound" that many quarts-controlled DD turntables are drabbed with.
The EDS1000 motor is servo controlled, with hall elements as "commutators" as far as I have understood it. That means a very smooth rotation.

I will post pictures with details from the underside soon. The motor will be boltet to the slate plinth, I just have to enlarge the grooves that the bolts shall sit in.

Kind Regards

Trond Kjetil

[mosin]

Hi,

That's a really nice project that shows a really creative flair. I'm interested in knowing what difference you hear after you mount the motor in slate. It affected mine greatly, much to the better, I am happy to say.

Regards,
Win

[trondkj]

The slate improved the sound compared to the original Dual 701. Dual 701 is not a bad design, but it's arm could be better, somewhat overengineered to my liking.

I was not very satisfied with the stroboscope light, because I wanted the stroboscope to be visible during record playing. The stroboscope is printed at the underside of the acrylic platter, and with the light emitting diodes under the printing, the stroboscope was only visible without a record on the platter.

I did use this circuit for the stroboscope light:



I replaced the leds with a brighter one taken from a broken computer mouse and put a couple of zeners in the circuit:



The result was a much brighter and sharper blinking, so that the stroboscope got clearer and sharper. I placed the led behind the platter, angled slightly upwards, and now I can see the stroboscope clearly through the edge of the platter.

[Iain McNeill]

nicely engineered... again!

How about etching a little animation sequence around the edge. Rabbit hopping along or something that could loop? That'd be cool.

[Shaun]

Very lovely!

Can you tell me about the strobe markings? Does the platter come with those markings? I could not find the platter on DIY HiFi's site. Do you have a link?

[trondkj]

Thank you again

Shaun, the platter is the one from the BIX tt, just email them and ask to buy parts. That was no problem.

The platter came with the markings.

[Shaun]

Thanks. I'll contact them.

I also meant to ask: what is the mass of the platter?