This kit tone arm was published in Audio Amateur 4/82 and I got one in a trade
still in the box. I'm wondering if anyone has built it, seen it work, or heard
anything good/bad about it?
I looked over the documentation and remember reading the article when it came out.
What I like about it is that it has a pivot like a normal arm but with photo sensors for
when it goes even slightly off linear which are used to ramp up or down the servo
speed. This way if the servo fails it just works like a normal arm but with the usual
tracking error, the bearing also, sort of decouples the arm from the servo movement.
Clever, I like that aspect.
still in the box. I'm wondering if anyone has built it, seen it work, or heard
anything good/bad about it?
I looked over the documentation and remember reading the article when it came out.
What I like about it is that it has a pivot like a normal arm but with photo sensors for
when it goes even slightly off linear which are used to ramp up or down the servo
speed. This way if the servo fails it just works like a normal arm but with the usual
tracking error, the bearing also, sort of decouples the arm from the servo movement.
Clever, I like that aspect.
Never heard of it but it's certainly intriguing.
Any chance you could add some pictures as it's a rarity and I suspect many will never have seen one.
Any chance you could add some pictures as it's a rarity and I suspect many will never have seen one.
The sensors are below and behind the head shell, they might still be in the box
since I don't see them in the pics.
since I don't see them in the pics.
Worth the time? I should think so! Certainly worth it as a learning experience IMO, I've always wanted a linear tonearm but it's never been a priority (speakers first, always, and my linn isn't too shabby).
Yes, I do. I fell for this same post over on another forum. I scanned and posted the entire aa 4/82 construction article in response, with nary a comment or thank you.
Looks like the moderator(s) over there took the thread down.
Ray K
Looks like the moderator(s) over there took the thread down.
Ray K
Me, click bait? Check my other threads before accusing.
If you have the article scanned please post it for others who are interested.
I've not heard of anyone who has built this claiming that it works well.
If you have the article scanned please post it for others who are interested.
I've not heard of anyone who has built this claiming that it works well.
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Nope. At the time it was published, I already had 2 Rabco tangent trackers that worked fine, so had no need.
Just happen to have every issue of TAA, so when someone is looking for an article, I'll try to oblige.
It's an intriguing design though, servo that runs at nominal groove pitch so no major dithering, and the unusual optical trigger method.
You're the guinea pig🙂. Get 'er built! Let us know how it works!
and it came with a motor to get you started. that's nice.
One thing I'm not sure I like is no locking nuts on the vertical pivot bearings A6. At least on one of them.
One thing I'm not sure I like is no locking nuts on the vertical pivot bearings A6. At least on one of them.
Reading the article reminded me that this was also in Wireless World.
This post by Trad at VA seems to confirm it:
References on DIY tonearms:
1. R. Cooper, A Tangential Tracking Tonearm, The Audio Amateur, 4/1982 (also reprinted in The LP Is Back!).
2. D. Read, Simple Pickup Arm Design, Wireless World, November 1980.
3. R. Cooper, Practical Parallel-Tracking Pickup Arm [Part 1], Wireless World, December 1979.
4. R. Cooper, Practical Parallel-Tracking Pickup Arm--2, Wireless World, January 1980.
5. R. Cooper, Mercury Switch for Parallel-Tracking Pickup Arm, Wireless World, April 1980.
6. R. Cooper, Parallel-Tracking Pickup Arm Modifications and Improvements, Wireless World, July 1981.
7. E. Lowinger, The Bizarm, Wireless World, December 1977.
8. D. Ruether, The Praying Mantis, The Audio Amateur, 2/1976 (also reprinted in The LP Is Back!).
9. R. Sanders, A Do-It-Yourself Tonearm, The Audio Amateur 2/1973 (also reprinted in The LP Is Back!).
10. D. Bartholomew, Unipivot Arm, Hi-Fi News & Record Review, April 1972.
11. R. Ockleshaw, Pickup Arm Design for Home Construction, Wireless World, November 1971.
12. J. Bickerstaffe, Building the Woggle Arm, Hi-Fi News & Record Review, October 1971.
13. J.S. Wright, Approach to Pick-Up Arm Design, Wireless World, June 1967.
14. J. Bickerstaffe, Torsional Stability and the Unipivot, Part 1, Wireless World, January 1966.
15. J. Bickerstaffe, Torsional Stability and the Unipivot, Part 2, Wireless World, February 1966.
Reference [11] is in fact one part in a three-part series describing the construction of not only an arm but also a turntable (using a factory-made platter) and a wow & flutter meter. The other two parts are:
16. R. Ockleshaw, Turntable Design for Home Construction, Wireless World, October 1971.
17. R. Ockleshaw, Novel Wow and Flutter Meter, Wireless World, December 1971.
Even if one is not contemplating the actual construction of a tonearm, it is fascinating to read about the various designs. It goes without saying that for anyone seriously thinking of building a (pivoted) tonearm, the classic papers by Lofgren, Baerwald, Bauer, Seagrave, Stevenson and/or Randhawa on tonearm geometry are required reading.
This post by Trad at VA seems to confirm it:
References on DIY tonearms:
1. R. Cooper, A Tangential Tracking Tonearm, The Audio Amateur, 4/1982 (also reprinted in The LP Is Back!).
2. D. Read, Simple Pickup Arm Design, Wireless World, November 1980.
3. R. Cooper, Practical Parallel-Tracking Pickup Arm [Part 1], Wireless World, December 1979.
4. R. Cooper, Practical Parallel-Tracking Pickup Arm--2, Wireless World, January 1980.
5. R. Cooper, Mercury Switch for Parallel-Tracking Pickup Arm, Wireless World, April 1980.
6. R. Cooper, Parallel-Tracking Pickup Arm Modifications and Improvements, Wireless World, July 1981.
7. E. Lowinger, The Bizarm, Wireless World, December 1977.
8. D. Ruether, The Praying Mantis, The Audio Amateur, 2/1976 (also reprinted in The LP Is Back!).
9. R. Sanders, A Do-It-Yourself Tonearm, The Audio Amateur 2/1973 (also reprinted in The LP Is Back!).
10. D. Bartholomew, Unipivot Arm, Hi-Fi News & Record Review, April 1972.
11. R. Ockleshaw, Pickup Arm Design for Home Construction, Wireless World, November 1971.
12. J. Bickerstaffe, Building the Woggle Arm, Hi-Fi News & Record Review, October 1971.
13. J.S. Wright, Approach to Pick-Up Arm Design, Wireless World, June 1967.
14. J. Bickerstaffe, Torsional Stability and the Unipivot, Part 1, Wireless World, January 1966.
15. J. Bickerstaffe, Torsional Stability and the Unipivot, Part 2, Wireless World, February 1966.
Reference [11] is in fact one part in a three-part series describing the construction of not only an arm but also a turntable (using a factory-made platter) and a wow & flutter meter. The other two parts are:
16. R. Ockleshaw, Turntable Design for Home Construction, Wireless World, October 1971.
17. R. Ockleshaw, Novel Wow and Flutter Meter, Wireless World, December 1971.
Even if one is not contemplating the actual construction of a tonearm, it is fascinating to read about the various designs. It goes without saying that for anyone seriously thinking of building a (pivoted) tonearm, the classic papers by Lofgren, Baerwald, Bauer, Seagrave, Stevenson and/or Randhawa on tonearm geometry are required reading.
I remember reading one of the original articles in Wireless World in a magazine store in Boston in 1979 - I assume it was R Cooper's. I was aflame to build it, but had none of the skills or equipment necessary. But as a kit, it would be a no brainer whether to build it or not.
I hope you build it, Pete.
I hope you build it, Pete.
