Its fascinating following this thread, but one flippant thought did strike me, a candidate piece of vinyl for listening tests: Hawkwind – Levitation (1987, Vinyl) - Discogs
I was not referring to arm movement resonance in this post, sorry if I was confusing.
I was referring to vibration energy traveling inside the arm wand. The existing mag-lev is not capable of testing internal wand vibration control.
The new arm is designed so the CW forms part of the energy minimization mechanism. The goal is to reduce to a minimum energy reflected back to the HS from the bearing.
The arm tube has a variable taper and wall thickness to reduce remaining vibration energy returning to the HS by having it bounce around inside the wand. There is a disk of Lead between the AL wand and Brass CW stub. Lead allows more than 95% of the energy to travel through to the Brass CW stub. The CW is also made from Lead, vibration energy then enters the CW with less than 6% reflection.
Further 'Mag-Lev' experiments?
Fantastic effort @warrjon ... I'm sure your build(s) will be really rewarding and great fun to play records with - brings back memories of the 80s + 90s when I was trying to push the art a fraction forward! Are you planing any further 'Mag-Lev' experiments? Please keep us posted if so.
Fantastic effort @warrjon ... I'm sure your build(s) will be really rewarding and great fun to play records with - brings back memories of the 80s + 90s when I was trying to push the art a fraction forward! Are you planing any further 'Mag-Lev' experiments? Please keep us posted if so.
denon dp29f TT
hi,
a bit off subject..but i need some help
I have a denon DP29f turntable. are there any improvements possible in this kind. currently i get fairly loud sound such that my computer 2.0 channel speakers cant be pushed beyond half volume. else the sound distorts. whats really going on? the sound separation is good though and the detail i voice has improved after a adjusted the azimuth a little by hearing tests. this TT sadly has no other adjustments that i can make.. right?
would happy if anyone can give me a few tips o this TT and setting it up correctly.. I am new to using TT.
thanks!
Amit
hi,
a bit off subject..but i need some help
I have a denon DP29f turntable. are there any improvements possible in this kind. currently i get fairly loud sound such that my computer 2.0 channel speakers cant be pushed beyond half volume. else the sound distorts. whats really going on? the sound separation is good though and the detail i voice has improved after a adjusted the azimuth a little by hearing tests. this TT sadly has no other adjustments that i can make.. right?
would happy if anyone can give me a few tips o this TT and setting it up correctly.. I am new to using TT.
thanks!
Amit
No excuse whatsoever to pollute such an interesting thread. Start you own and ask a moderator to move your post.
Could you not make the arm track the warp of the record using short range radar? Essentially have a radar on the end of the arm before the cartridge. The radar senses the distance and the arm actuator (ie the balance electromagnet) then raises or lowers the arm to track the warp.
This assumes a flat vertical warp that has not rotated the tracks (no head as far as I know does this anyway). Any horizontal warp is left to the friction of the stylus in this case - really about the only way perhaps to solve that well is to play the record and record the arm movements, analyse and then replay the record with arm actuator adjustments made from the previous analysis, leaving the stylus to now simply play the track without being having to correct the arm position. You could store the analysis for future playing.
This assumes a flat vertical warp that has not rotated the tracks (no head as far as I know does this anyway). Any horizontal warp is left to the friction of the stylus in this case - really about the only way perhaps to solve that well is to play the record and record the arm movements, analyse and then replay the record with arm actuator adjustments made from the previous analysis, leaving the stylus to now simply play the track without being having to correct the arm position. You could store the analysis for future playing.
Distance sensing would likely be easier with an optical system.
Some compact, affordable examples would include the Reflective Object Sensors QRD1113_1114 and QRE1113 (originally made by Fairchild, now by OnSemi).
https://www.onsemi.com/pdf/datasheet/qrd1114-d.pdf
https://www.onsemi.com/pdf/datasheet/qre1113-d.pdf
If a very precise distance sensing system could be used in conjunction with a peripheral record clamp or vacuum clamp, the tonearm would no longer have any need for vertical movement, opening a path to a rather different mechanical structure from most previous tonearm designs.
Some compact, affordable examples would include the Reflective Object Sensors QRD1113_1114 and QRE1113 (originally made by Fairchild, now by OnSemi).
https://www.onsemi.com/pdf/datasheet/qrd1114-d.pdf
https://www.onsemi.com/pdf/datasheet/qre1113-d.pdf
If a very precise distance sensing system could be used in conjunction with a peripheral record clamp or vacuum clamp, the tonearm would no longer have any need for vertical movement, opening a path to a rather different mechanical structure from most previous tonearm designs.
Flywheel analysis
Thanks for this link to a patent. Interesting that its analysis starts with the observation that a of a tone arm behaves mechanically just like a flywheel - the same as I did in my essay which started this thread.
Thanks for this link to a patent. Interesting that its analysis starts with the observation that a of a tone arm behaves mechanically just like a flywheel - the same as I did in my essay which started this thread.
Why not just go the 'whole hog' and dispense with a mechanical contact cartridge and read the grooves directly with lasers? As a bonus such a system can easily track warps too!
https://www.elpj.com/stylus-vs-laser-why-the-laser-turntable-excels/
ELP LT-1LRC Laser Turntable - The Absolute Sound
Right, which is precisely why I posted the link
.I've heard (and helped set up) various iterations of the Finial concept over the decades, but I can't recall a single instance where the sound surpassed the "adequate" level. Not saying that it can't be done; perhaps others will have found the sound to be closer to their tastes than I did.
Last edited:
Wow! Good stuff. I never heard a laser pick up, but held deep suspicions that it couldn't be as 'accurate' due having to be far too complicated to first track, then pick up such tiny modulations as mechanical tracing achieves, despite all the compromises of dragging diamonds on plastic! If I remember correctly, I think Stevie Wonder invested in a laser player company years ago.