bush-to-220-pk10
An externally hosted image should be here but it was not working when we last tested it.
Problems with ball bearings
There are inherent drawbacks of the construction with ball bearings. Static friction is higher than dynamic friction, so the stylus “sees” different effective masses depending on whether the carriage is static or moving. If the ball bearing has a radial play, this is another source of non-ideal behaviour since when the movement is small the arm is pivoting in an arc.
The vertical movement is constrained by the “scratching” of the outer race of the bearings to the point that it is impossible to adjust the VTF.
My design of a tonearm gliding on ferrofluid is free of these issues but admittedly it is not totally rigid in the longitudinal direction, although the thickness of the liquid film can be very small. I will come up with a new design.
There are inherent drawbacks of the construction with ball bearings. Static friction is higher than dynamic friction, so the stylus “sees” different effective masses depending on whether the carriage is static or moving. If the ball bearing has a radial play, this is another source of non-ideal behaviour since when the movement is small the arm is pivoting in an arc.
The vertical movement is constrained by the “scratching” of the outer race of the bearings to the point that it is impossible to adjust the VTF.
My design of a tonearm gliding on ferrofluid is free of these issues but admittedly it is not totally rigid in the longitudinal direction, although the thickness of the liquid film can be very small. I will come up with a new design.
alighiszem, I'm really interested in trying the ferro-fluid idea. How large/strong are the magnets you use to capture the ferro-fluid? I'm concerned that the fringing fields could degrade the performance if not damage the cartridge magnets.
What is the tradeoff between not being totally rigid in the longitudinal direction, and not having the admitted problems of ball bearings? I suspect and hope to verify that the tradeoff is going to weigh heavily in favor of the liquid film.
BillG
How does it run?
I think I have to tweak it a little more. Not that impressed. Its good don't get me wrong but my cd system is in general better.
Please bear in mind I am using a different system to my cd and I am pretty new to turntables..I built a salas phono stage, but have forgotten where I put it and it needs a power supply. I need to play awhile.
Also!!!! It is obvious that friction is a major factor in this set up. I think the wires I am using are a little thick. Twice the thickness of what is in the original tone arm.I need to order finer, more flexible gear
I have no way of setting the tracking weight properly until I get some scales. Moving the counterweight is affecting performance.
The copper wire space worked massively with the friction. I will order the correct part tho
Not getting any ultra bass...please note I don't want it:I have neighbours
Trebles are great, especially symbols and high hats.
Not that impressed by the dynamics,
At this stage, it has fulfilled its brief. That was to cheaply replace the original tone arm and like I said I think I need to do more work on set up and the rest of the kit is not as good as what my cd goes thru.
I think I have to tweak it a little more. Not that impressed. Its good don't get me wrong but my cd system is in general better.
Please bear in mind I am using a different system to my cd and I am pretty new to turntables..I built a salas phono stage, but have forgotten where I put it and it needs a power supply. I need to play awhile.
Also!!!! It is obvious that friction is a major factor in this set up. I think the wires I am using are a little thick. Twice the thickness of what is in the original tone arm.I need to order finer, more flexible gear
I have no way of setting the tracking weight properly until I get some scales. Moving the counterweight is affecting performance.
The copper wire space worked massively with the friction. I will order the correct part tho
Not getting any ultra bass...please note I don't want it:I have neighbours
Trebles are great, especially symbols and high hats.
Not that impressed by the dynamics,
At this stage, it has fulfilled its brief. That was to cheaply replace the original tone arm and like I said I think I need to do more work on set up and the rest of the kit is not as good as what my cd goes thru.
Thank you for your interest.
I used four 8 mm x 1 mm Neodym magnet discs. I experienced no degradation of performance because of the magnetic forces.
The logical choice for the wand the tonearm is gliding on would be copper, it is diamagnetic. The liquid film should be as thin as possible, that means just a tiny amount of ferrofluid should be on the magnets.
Technical design is a matter of compromises, for me low friction is important. Concerning rigidity, bass and attack were good enough for my ears, although my proof of concept was of rather low build quality.
Hi chokesrule,
If its all properly done up the wire will have a great effect on its movement in which I used Cardas lots due to its flexibility. It should definately impress, maybe it's the phono stage?. I run this arm through a Vendetta style phono, my own custom built Zero global feedback with adaptive bias monoblocks and Martin Logan ESL speakers so the system is far from a weak link
, and it wholly blows away the cd front on good pressings, this has me perplexed, although the build has evolved alot with additions and simplifications for resonance control.
Colin
If its all properly done up the wire will have a great effect on its movement in which I used Cardas lots due to its flexibility. It should definately impress, maybe it's the phono stage?. I run this arm through a Vendetta style phono, my own custom built Zero global feedback with adaptive bias monoblocks and Martin Logan ESL speakers so the system is far from a weak link
, and it wholly blows away the cd front on good pressings, this has me perplexed, although the build has evolved alot with additions and simplifications for resonance control.Colin
Hi Everyone
I had an Opus 3 Cantus and the wires were thin and very flexible-I changed this for what I thought was a better wire and had no end of trouble with mis-tracking-the wire was the culprit. Then I found the finest wire I've ever seen from Transcriptors (pricey tho for what it was) and this cleared up the problem.
With this arm, I am sure the wire has a major impact on tracking. Use the cheapo litz wire (and braid it) and you will find it far too stiff. I tried it this evening and no matter what I did, it kept mis-tracking. On the positive side, I was extremely impressed with the music in between-great separation and detail, super sound stage and certainly no lack of bass. Remember too, that things won't be helped by leaving the wire dangling around- again, look at pictures of the Opus 3, the wires need careful dressing and support to get best results.
Now to tracking force-Bo recommended you do this by eye- carefully lower the stylus and set the counter weight so the stylus depresses around 0.2-0.3mm into the body. I've used this method time and again and it seems to work well.
Regarding wire-I'm looking out for some thin, very flexible stuff-some of the thinner Cardas? Any ideas anyone?
I had an Opus 3 Cantus and the wires were thin and very flexible-I changed this for what I thought was a better wire and had no end of trouble with mis-tracking-the wire was the culprit. Then I found the finest wire I've ever seen from Transcriptors (pricey tho for what it was) and this cleared up the problem.
With this arm, I am sure the wire has a major impact on tracking. Use the cheapo litz wire (and braid it) and you will find it far too stiff. I tried it this evening and no matter what I did, it kept mis-tracking. On the positive side, I was extremely impressed with the music in between-great separation and detail, super sound stage and certainly no lack of bass. Remember too, that things won't be helped by leaving the wire dangling around- again, look at pictures of the Opus 3, the wires need careful dressing and support to get best results.
Now to tracking force-Bo recommended you do this by eye- carefully lower the stylus and set the counter weight so the stylus depresses around 0.2-0.3mm into the body. I've used this method time and again and it seems to work well.
Regarding wire-I'm looking out for some thin, very flexible stuff-some of the thinner Cardas? Any ideas anyone?
Colin
I have been playing about.
Become very happy with it
Changed to hd595s and a headphone amp
I must build a better adjustment system for the arm
Retrieving some very good detail
Easily can make out lyrics
I have got much better separation
The trebles are very good indeed
The listening is quiet in the background : I would say cd quiet
on the headphones much better dynamics
I will get this Salas thing I built going while waiting for the tone arm wire
I feel it was well worth the effort
thanks for sharing this idea
I have been playing about.
Become very happy with it
Changed to hd595s and a headphone amp
I must build a better adjustment system for the arm
Retrieving some very good detail
Easily can make out lyrics
I have got much better separation
The trebles are very good indeed
The listening is quiet in the background : I would say cd quiet
on the headphones much better dynamics
I will get this Salas thing I built going while waiting for the tone arm wire
I feel it was well worth the effort
thanks for sharing this idea
Excellent!, one must remember too that they will be missing out on the best on this arm if adjustments aren't spot on. Since its linear there should be a means to adjust azimuth, tube level, arm mounting to plinth and vta. All adjustments must be set with a record thickness, I spun about 6 consecutive sides last night, not a hitch in tracking.
Colin
Colin
the litz people list a 7/48, overall dia would be 0.0065mm about 42awg I think...
They also list 10/52 being 0.0036mm or about 48awg, no prices you have to get a quote.
At these gauges it might be getting hard to work with?
regards
James
They also list 10/52 being 0.0036mm or about 48awg, no prices you have to get a quote.
At these gauges it might be getting hard to work with?
regards
James
Hi Colin and others,
I've been watching with great interest and ready to order parts. Does anyone have a bill of material? Sources for parts (USA)? Seems the bearing ID and the OD of the hardware (or internal spacers) that is used to secure them, would be critical to avoid misalignment and slop of the four bearings. Also what are people using for bearings...open, sealed, dry, lubed, steel, ceramic? Metric or US?
BTW I second the Cardas 33awg Litz wire. I have used it in all my other tonearms. Very flexible, IMHO better than Silver wire.
I've been watching with great interest and ready to order parts. Does anyone have a bill of material? Sources for parts (USA)? Seems the bearing ID and the OD of the hardware (or internal spacers) that is used to secure them, would be critical to avoid misalignment and slop of the four bearings. Also what are people using for bearings...open, sealed, dry, lubed, steel, ceramic? Metric or US?
BTW I second the Cardas 33awg Litz wire. I have used it in all my other tonearms. Very flexible, IMHO better than Silver wire.