Having made the Nanook uni-pivot, I have sort of been enthused to start a small production line. I only have five TTs and will need a few arms for when I get numbers 6 and 7.
The one problem I had with the Nanook was feedback. Above a certain volume it just went out of control. Not sure why or if anyone else has had this problem.
Anyway, I was taking some old hard disks apart and the motors looked perfect for using as the horizontal bearing in a tonearm. There is absolutely no play and they are very free running.
I converted the uni-pivot into a 10" and have built a 12" as well.
Details to complete but given the sound with the 10" just resting on an old Garrard SP25, there is definitely some performance in these arms. I will make a suitable support for my Origin Live based TT and see what they are really capable of. There is only a Shure M75ED in the 10" so more to come in that direction too.
The one problem I had with the Nanook was feedback. Above a certain volume it just went out of control. Not sure why or if anyone else has had this problem.
Anyway, I was taking some old hard disks apart and the motors looked perfect for using as the horizontal bearing in a tonearm. There is absolutely no play and they are very free running.
I converted the uni-pivot into a 10" and have built a 12" as well.
Details to complete but given the sound with the 10" just resting on an old Garrard SP25, there is definitely some performance in these arms. I will make a suitable support for my Origin Live based TT and see what they are really capable of. There is only a Shure M75ED in the 10" so more to come in that direction too.
An externally hosted image should be here but it was not working when we last tested it.
What a setup. You gotta say whoa.
<< The one problem I had with the Nanook was feedback. Above a certain volume it just went out of control. Not sure why... >>
It's an off chance, but it might not be feedback, it might be mechanical resonance. You might try changing the mass of something, or the length of something, or...something.
Or another off chance, it might be feedback from the speakers to the tone arm. The sound waves from the speakers being strong enough to vibrate the tone arm.
<< The one problem I had with the Nanook was feedback. Above a certain volume it just went out of control. Not sure why... >>
It's an off chance, but it might not be feedback, it might be mechanical resonance. You might try changing the mass of something, or the length of something, or...something.
Or another off chance, it might be feedback from the speakers to the tone arm. The sound waves from the speakers being strong enough to vibrate the tone arm.
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Thanks for the help. You are quite right. It is an arm resonance problem. I wrapped the arm tubes in plastic tape and the feedback has 'almost' disappeared. The volume has to be at insane levels to set it off however.
Now I've done that, the 10" arm sounds better than the 12" whereas before, it was the other way round. All strange stuff this. Having absolutely no technical knowledge and just bunging stuff together to see what works makes for a lot of fun😱
Still playing
The 12" arm is now a permanent fixture on my OL based deck. I prefer it to the OL Rega250 now. I tried the technics in it but it didn't match at all well but sounds terrific with a cheap Audio Technica cartridge.
Also trying an arm with the pivot to one side and a straight headshell. This one sounds very interesting and will have further development. It is highly critical of the balance weight position. The weight of the arm including the counterweight has to be offset quite precisely or the bearing loads up and it hesitates whilst tracking. Get it spot on and it tracks anything with terrific bass and rock solid image. It has a Goldring Elan in which seems to suit it very well but I'll put something better in once it's sorted 100%.
The 12" arm is now a permanent fixture on my OL based deck. I prefer it to the OL Rega250 now. I tried the technics in it but it didn't match at all well but sounds terrific with a cheap Audio Technica cartridge.
Also trying an arm with the pivot to one side and a straight headshell. This one sounds very interesting and will have further development. It is highly critical of the balance weight position. The weight of the arm including the counterweight has to be offset quite precisely or the bearing loads up and it hesitates whilst tracking. Get it spot on and it tracks anything with terrific bass and rock solid image. It has a Goldring Elan in which seems to suit it very well but I'll put something better in once it's sorted 100%.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Also trying an arm with the pivot to one side and a straight headshell. This one sounds very interesting and will have further development. It is highly critical of the balance weight position. The weight of the arm including the counterweight has to be offset quite precisely or the bearing loads up and it hesitates whilst tracking. Get it spot on and it tracks anything with terrific bass and rock solid image. It has a Goldring Elan in which seems to suit it very well but I'll put something better in once it's sorted 100%.
Fascinating creation, Gus! Please contribute more information, if possible, to the other thread in this forum that discusses this particular genre of tonearms. We can all learn along the way. Thanks for posting!
Your arm has a striking resemblance to the creation by Doug Tuthill in this post. But yours doesn't appear to have a guiding mechanism to conform to the quasi "Birch" geometry.
Ha! So much for originality!!🙄Fascinating creation, Gus! Please contribute more information, if possible, to the other thread in this forum that discusses this particular genre of tonearms. We can all learn along the way. Thanks for posting!
Your arm has a striking resemblance to the creation by Doug Tuthill in this post. But yours doesn't appear to have a guiding mechanism to conform to the quasi "Birch" geometry.
I wouldn't know what a quasi Birch geometry was if it bit me on the bum!! I just bung stuff together and see if it works. If you throw enough ideas into the pond, eventually, one of them might float.
I'm not sure what I can contribute to the other threads, there is no science or reasoning behind what i do. I'm a guitar maker who just dabbles in hi-fi as it is so closely connected to my main passion.
When my brother in law has made my suggested adjustments to the parallel tracker we are developing, then I may have something relevant to say. He actually knows what he is doing as he is (was before he retired - now just a genius) a design engineer.
A new one
Right then...here is the latest try. Parallel tracker using the principle of a Sarrus Linkage - Sarrus linkage - Wikipedia, the free encyclopedia
To say that it was difficult to adjust would be a slight understatement. Incredibly sensitive to level and balance. However, when it works, I have never heard anything to approach it for sheer musical information.
We have to work a few things out and make it prettier but the principle seems a good one. The main problem is finding a way to incorporate a lift.
Right then...here is the latest try. Parallel tracker using the principle of a Sarrus Linkage - Sarrus linkage - Wikipedia, the free encyclopedia
To say that it was difficult to adjust would be a slight understatement. Incredibly sensitive to level and balance. However, when it works, I have never heard anything to approach it for sheer musical information.
We have to work a few things out and make it prettier but the principle seems a good one. The main problem is finding a way to incorporate a lift.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Wow Gus.
Where do you find the time?? You have got to be the incarnation of the people this forum was meant for😉
I cant even try to figure out the way this tracker moves across the surface. If it was a steam-driven locomotive yes, but how the h... can you move this contraption with a diamond attached to a cantilever😕 Are there any way you can post a video of "the thing" in action? Thumbs up!
Steen
Where do you find the time?? You have got to be the incarnation of the people this forum was meant for😉
I cant even try to figure out the way this tracker moves across the surface. If it was a steam-driven locomotive yes, but how the h... can you move this contraption with a diamond attached to a cantilever😕 Are there any way you can post a video of "the thing" in action? Thumbs up!
Steen
The thing is so free moving that just blowing on it will send it skating to full extension😱
It's almost too much as it makes it so sensitive to level that it really is difficult to adjust it finely enough. The main balance weight has to exactly equal the weight of the arm and cartridge or it zooms in one direction or the other depending on which cart I try. You need the balance weight to offset the vertical pressure, the horizontal bit seems to add very little resistance of any kind.
The Shure seems a good match to the arm. Guitar has a lovely resonance and decay and you can hear everything the players nails are doing against the strings and his fingers on the fretboard. Everything a top notch arm should offer.
Never tried doing video but I'll have a look into it - if I can find the time😀
I have to try and finish the plastering to our dining room to be, then do the bathroom, make a new gate for our neighbour and, I have just been informed, for us. I expect it will then be time to mow the grass again.
Who knows where the time goes?? I can't decide which version I prefer, the dark one by Sandy Denny or the cheerful one by Fairport.
How the hell do I add a link to embed????
This is the link!
https://www.youtube.com/watch?v=vRXUl9gN-NM&feature=youtu.be
I am waiting for some leads to the Quads as I re-arranged the room so there are a small pair of rubbish boxes pro-tem. The camera is rubbish too so the sound quality is awful. You probably can't tell its Paco Pena playing flamenco!!
Just a short clip to show that it tracks OK.
This is the link!
https://www.youtube.com/watch?v=vRXUl9gN-NM&feature=youtu.be
I am waiting for some leads to the Quads as I re-arranged the room so there are a small pair of rubbish boxes pro-tem. The camera is rubbish too so the sound quality is awful. You probably can't tell its Paco Pena playing flamenco!!
Just a short clip to show that it tracks OK.
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I've wondered about that arrangement, which the Bosch glide saw uses instead of tubes, but you've done it man! Killer.
On the youtube page click Share, then click Embed. The link it gives "should" work, depending on this site's bulletin board settings - let's see:
<iframe width="420" height="315" src="https://www.youtube.com/embed/vRXUl9gN-NM" frameborder="0" allowfullscreen></iframe>
ETA: Nope, it needs HTML enabled in the BBS software, and there's surely no equivalent BB/IMG code.
That's certainly the most bizarre and unlikely-looking tonearm I've seen! The two arms, horizontal and vertical, look like they could be problematic, as each one has three bearings, for a total of six bearings - THEN you have another bearing for the vertical pivot.
I think the short "arm" for the vertical pivot is interesting (in a positive way), as it's such low effective mass and can easily track record warps.
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I think I'll just leave it as a link to YouTube!!
Bizarre and unlikely🙂 Yup, but by 'eck it works!! I am about to pack it it up and send it back to my brother in law in the UK for some modification. He's the engineer, I just have ideas. If its wood I can do it but precision metalwork is beyond me. We are going to incorporate some easy adjustment of the slope. Packing is not the easiest way to achieve what we need. So I had a listen on headphones and I could cry. I have to listen to ordinary arms for a couple of weeks until I get it back. I am bereft🙁
Hello gus 3049
I think your latest tonearm is ingenious. I wonder if it could be made to be commercially successful?
Am I correct in assuming that the tonearm has a total of 14 ball bearings?
Sincerely,
Ralf
I think your latest tonearm is ingenious. I wonder if it could be made to be commercially successful?
Am I correct in assuming that the tonearm has a total of 14 ball bearings?
Sincerely,
Ralf
Thanks but no, it only has six bearings. Each arm articulates with a fixed spigot into a bearing. There will be another bearing when we add a proper arm to match the rest of the mechanism.
We did discuss the commercial possibilities and it certainly sounds good enough to warrant it I think. However, we couldn't justify the cost of protecting the design plus the fact that Bob is 85 and I'm 68 rather means that neither of us particularly wants the hassle. I think the major drawback is the difficulty of making it more practical with a lift etc. I'm sure we could work something out however. It's getting an adjustment system for slope at the moment.
I am quite keen to try an adaption where we revolve the whole thing through 45 degrees and have the balance weight on a string and pulley through the centre. That way, both sections will have equal stresses and it will be easier to add or subtract weight to get the slight help from gravity that it relies on.
I haven't decided if it's going to be called BAGS or RAGS - probably BAGS (BobArnoldGordonSteadman)
What ever happens to it, the process has been most enjoyable. there is no doubt that the 'I did that' factor adds to the fun and makes it sound so much better too🙂
As our linear tracker has gone back to the UK for some fettling, I thought I'd try something simple - more my sort of thing🙂
A bit of aluminium angle and some V groove bearings. It took all of half an hour to make but the bearings needed a couple of hours degreasing before they ran free. I've wired it up now and just need to add a support for the wire.
Sounds pretty good but it doesn't have the bass control of the 'proper' one.
Amazing what good sound you can get from something so quick, cheap and easy to make. Fitting a lift will be easy with this one too.
A bit of aluminium angle and some V groove bearings. It took all of half an hour to make but the bearings needed a couple of hours degreasing before they ran free. I've wired it up now and just need to add a support for the wire.
Sounds pretty good but it doesn't have the bass control of the 'proper' one.
Amazing what good sound you can get from something so quick, cheap and easy to make. Fitting a lift will be easy with this one too.
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