My DIY Turntables and Schroeder based tonearm

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Here are some pics of my DIY Turntables and Schroeder based tonearm. I'll post some more detailed pics as soon as i get my digital camera back. (Did you heard that Chris:goodbad: )

Regards
 

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Beautiful, stylish, work quality well above average DIY - I'm jealous... Congrats!
Give us some more details! Clearaudio-style TT is especially good - want to know more: bearing, motor/controller, materials used. How are bearing and legs connected to the double-deck base?
Would be great if you share your experience with the rest of community.
Best regards,
Michael
 
Hello M.

The basic material is solid PERSPEX (acrylic) which i think is a bit harder than Plexiglass and easier to work with. All the pieces were made from one solid piece, even the platter which is 76mm high.
The metal parts (spacers between subchasis,support plates, motor rod, tonearm, rack) are made of solid, very hard, Stainless Steel 314.
The spacers have Silicon O-Rings between them and the subchasis, to avoid direct contact and to rather reduse any vibrations coming from the rack which is also solid and weights about 65Kg.
The bearing is a classic thrust ball, plate configuration which are made of Tungsten Carbide (Ball) and Cobaltium (Plate).
For the point of friction i tried lots of materials, like Teflon, Phosphore Bronze, Delrin but it ended with (two 8mm rings with a 5mm space between them to hold some very thin oil) a thermoplastic material called VESCONITE.
These two rings are also having about 10, 1mm holes to rather hold some oil, because the overall gap between rings and main rod was succesfully held down to 0.05mm.
The main rod have a coat of highly polished hard Chromium to rather reduse friction .
The motor is build in a massive 14Kg solid stainless steel base and is a synchronous type made from PREMOTEC, but i will try a DC from MAXON in the near future.
The tonearm is of my own design inspired from the exsellent work of Mr. Shroeder. It is made of stanless steel and the armtube is made of carbon fiber. The internal cables are from Siltech and the connectors are WBT. That's all (ouf).


Fell free to mail me if you need any more info at:
ktzivleris@hotmail.com

Regards from GREECE
Konstantin
 
Thank you, Konstantin for your information!
I'm puzzled a bit about introducing compliant silicone O-rings in vibration path. It seems to be in contradiction with the high mass unsuspended design motto: to damp without compromizing vertical stiffness. The same note applied to the thrust plate - is VESCONITE more compliant than delrin?
:scratch:
Another bunch of questions: have you abandoned previous (?) SS platter design (Simon Yorke - like)? What is the difference in sonic signature in comparison with the solid perspex?
Cheers,
Michael
 
Michael hi,

The use of O-rings does not in any way compromizing vertical stiffness for two reasons. First the silicon the o-rings are made of is not the soft silicon very often seen in commercial turntables as belts. It is harder than the BUNA o-rings, the standard, black ones. Actually there are two o-rings where there is contact between perpex and steel. A 16mm in the center and a 46mm on the outside.
The two subchasis are hold in place by a 12mm high tensil steel bolt (from the feet cones to the upper part) which is very tight. The result is rock steady and i avoid the risk to damage or brake the subchasis by overtighing the bolt, which must be very tight.

The thrust plate is made of Cobaltium (lifetime guaranteed).
Vesconite rings are used at the side point of friction in the bearing.

The difference in sonic signature?
Well, let me put it this way.
The S7 it's more on the clinic precision side, something that i don't like because it lacks (not allways, but very often) the ''feeling of musicality''. For the same reason i prefer tubes Vs solid state amplification, Morch tonearms Vs SME, Quad ESL Vs JM Lab.

The acrylic in my opinion has more natural and relaxed sound.



Regards, K.
 
Hi Konstantin,
Some more questions regarding basic design, with yor permission.
How is the bearing base connected to the subchassis plates (to both of them?)? Do you see any particular advantages of double-deck design comparing to, say, simple lead-loaded base? Your silicone rings are very hard pressed, but there is still no direct contact between perspex and metal spacers, if I get you right?
Do you have any experience (or plan to try) with lead- loaded acrylic platter? Do you prefer stand alone tonearm base or integrated one?
Thank you
Michael
 
Hello everybody,


MIchael , the bearing is connected to the upper subchasis only and there are also o-rings (2) between the plate and bearing.

I tried some very heavy solid granite bases (the last one was an overkill 150Kg) in the past but (sonically) i like acrylic more, and,you CAN find a place to put it on.

No, there is no direct contact between perspex and metal spacers.

As you allready know, lead-shots is not the only way to add mass to the perimeter of the platter, which ressults in better speed stability. The trick is to to have the platter's mass (and inertia) dominate the motor. The risk with lead shots is that you very easilly can take the platter out of balance, unless offcourse you have a balancing machine. What i will try in the near future is a solid stainless steel ring (300mm OD X 150mm ID X 30mm Thick) bolted under the platter.:idea:

Stand alone tonearm base allow you to set the cartridge overhang without changing the offset angle of the cartridge by moving the arm base to set the overhang.

Audiofanatic,
The cartridge in the pic is the Ortofon MC-30 Supreme (superb for the price) since my favorite LYRA Lydian is send for retip.

With best regards
K
 
Ex-Moderator
Joined 2003
konstantin said:
The cartridge in the pic is the Ortofon MC-30 Supreme (superb for the price) since my favorite LYRA Lydian is send for retip.

If you have the nerve (and you probably do, having built a turntable), removing the body from Ortofons makes them sound much better. I've not taken the body off a Supreme, but it looks very similar construction to the Quattro and MC20 before it. If you do take the body off, the magnet/motor is suspended by one sproggit in the manner of a tuning fork. A small balsa wedge jammed between the magnet and the top plate tames the treble. The final effect is, well, less boxy...
 
krishu hi,

The tonearm is made by SME V series standards (Offset angle, Splindle to tonearm pivot, overhang, etc.), the armtube is made of Carbon-Fiber and all the rest is made of stainless steel.

The magnets are rare earth neodumium (N40 Grade).

The antiskating is fully adjustable and it is a Nylon String-Weight configuration.


Best regards
K.
 
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