My DIY Turntables and Schroeder based tonearm

[konstantin]

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.

[EC8010]

I am deeply envious. What did you use as your thrust pad for the platter bearing?

[konstantin]

Hello,

Actually is COBALT, sorry for the typo.
Cobalt is a brittle, hard metal, resembling iron and nickel and it's used for high-speed, heavy-duty, high temperature cutting tools.
It is also has very high resistance to oxidation.


Regards
K

[livemusic]

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

[Audiofanatic]

Konstantin,

This is cute! Congrats !

What cartridge do you use for this wonderfull art?

You can shake hans with Peter Daniel, you guy's are a mazing!

Nice work!!!!!!!!!!!!!!!!!

Audiofanatic

[konstantin]

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.

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

[EC8010]

Originally posted by konstantin
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...

[konstantin]

Hi,

Yes, I have a friend who did it with great results.
I'll do it when i'll find the time.

[krishu]

Hi Konstantin,

how did you do the tonearm? What magnets did you use? What abou antiskating? Is it 9 inches? Please, explain or show close-up photos.

Thanks
Christian.

[konstantin]

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.