Good morning!
I am (ahem) working on my TD-125 to make it fully functional again.
Shouldn't be too far off as it seems to be in good condition and only some little/cosmetic details need to adressed.
One of them is the tonearm-board, which I'd like to replace (it has an obsolete hole from the thorens/tp-25 front-operated cue-mechanism).
Following up, I want to make a second board to fit a FR-24...
Beside the ovious: precision, correct distance, enough space for headshell + counterweight, is there a rule (of thumb) for the placement of the tone-arm?
What material would you recomment? HDF? Alucobond? POM?
In the PDF you'll find what I've got so far, the tonearm's size was scaled on the drawing (but not yet verified)...
I am (ahem) working on my TD-125 to make it fully functional again.
Shouldn't be too far off as it seems to be in good condition and only some little/cosmetic details need to adressed.
One of them is the tonearm-board, which I'd like to replace (it has an obsolete hole from the thorens/tp-25 front-operated cue-mechanism).
Following up, I want to make a second board to fit a FR-24...
Beside the ovious: precision, correct distance, enough space for headshell + counterweight, is there a rule (of thumb) for the placement of the tone-arm?
What material would you recomment? HDF? Alucobond? POM?
In the PDF you'll find what I've got so far, the tonearm's size was scaled on the drawing (but not yet verified)...
The tonearm board should be rigidly attached to the floating subchassis.
Go to Vinyl Engine & in their Data base find your T/T. That will show the spindle center to arm center distance. That is the measurement to place you arm on the T/T. Provided your arm is the same length as the standard tonearm.
Cheers
Cheers
Good morning! I think you have fundamentals there, just remember to check cable runs underneath the board. I see there is an SME 3009 drawn in you illustration, and the 3009 needs extra space for bucket and cables. Cables should not be touching the wrong parts, they can pick up vibrations from chassis. And they should not be hindering the functionality of the suspension, being too thick/stiff or with too long plugs. Position of tonearm with mini-DIN 5-pin can also be affected by rotation of plug and cable. Sometimes they need some space too. I speak from experience 😀.
As for materials, I find baltic birch plywood to be fine. My Heybrook TT2 is similar design, and Heybrook recommends 18mm baltic birch. HDF is good, I've also experimented with different composits, both home made and premade. I've used flooring tiles with good result: linoleum/HFD/cork composite with known damping factor. I prefer a not too hard board, I believe it should absorb vibrations, rather than reflect them. Thorens used MDF for TD160 mkII.
Look here for more in-depth explorations https://www.diyaudio.com/community/threads/diy-cld-plinth-design-a-measured-approach.312473/
Dagfinn
Hei dagfinn! This is good information, thank you!
I don’t have to worry for the SME, as it is a proven combo, and I have one.
The FR-24 is a little more problematic as its counterweight is much longer, and will need a custom/customized cover… (but it surely is a beautiful tonearm!)
Did you make the lino/multiplex/cork-sandwich yourself or is it a product? I am preparing plans to have a good basis for estimates for various materials, and arms…
I don’t have to worry for the SME, as it is a proven combo, and I have one.
The FR-24 is a little more problematic as its counterweight is much longer, and will need a custom/customized cover… (but it surely is a beautiful tonearm!)
Did you make the lino/multiplex/cork-sandwich yourself or is it a product? I am preparing plans to have a good basis for estimates for various materials, and arms…
It was commercial product, I had some left over from a floor 🙂. https://www.forbo.com/flooring/de-ch/produkte/linoleum/marmoleum/b534p7
It's a little thin for a larger board, I would sandwich it with something to get the right height and more rigidity.
It's a little thin for a larger board, I would sandwich it with something to get the right height and more rigidity.