Hi guys.
I have read several threads on building a linear tracking tonearm and plan to get involved. Plenty of material and design preferences are discussed in each thread but final testing seems to revolve around a builder's testimony to the arm's sound quality. Well sure. This makes sense. We are building it to listen to it, but when I think about building one of these, i wonder if it verifiable that it behaves the same during track 4 as it did during track 1.
Pardon me if this is an old idea but I have been looking for a single-frequency record. I have several test records with sweeps, single frequency bands, etc but I seek one with only one pitch across the entire side. This would allow me to play it thru the entire travel of the arm, log the data and examine the interchannel differences. Does anyone know of such a record? Thanks!
I have read several threads on building a linear tracking tonearm and plan to get involved. Plenty of material and design preferences are discussed in each thread but final testing seems to revolve around a builder's testimony to the arm's sound quality. Well sure. This makes sense. We are building it to listen to it, but when I think about building one of these, i wonder if it verifiable that it behaves the same during track 4 as it did during track 1.
Pardon me if this is an old idea but I have been looking for a single-frequency record. I have several test records with sweeps, single frequency bands, etc but I seek one with only one pitch across the entire side. This would allow me to play it thru the entire travel of the arm, log the data and examine the interchannel differences. Does anyone know of such a record? Thanks!
Hello pcb121055
It is somewhat unclear as to what you would like. Do you want to test a straight line tracking tone arm that someone else has built? Wouldn't that get complicated unless you and the maker lived reasonably close to each other?
The reason I am addressing your request is, that I built a straight line tracking tone arm in 2012 and am looking for someone to test it. Since I am only interested in the ultimate High-End design, the tester would have to have matching High-End equipment and "golden Ears". I have a very good turntable but the rest of my audio gear is mediocre. I enjoy listening to music as played back by my own tone arm but don't have the final word on its quality due to a high frequency hearing loss.
I can't help concerning the single frequency test record but I have a question:
Since in a straight line tracking tone arm, the geometrical relationship between the stylus and the groove is always the same, why do you need to conduct tests at different locations on the LP?
Sincerely,
Ralf
It is somewhat unclear as to what you would like. Do you want to test a straight line tracking tone arm that someone else has built? Wouldn't that get complicated unless you and the maker lived reasonably close to each other?
The reason I am addressing your request is, that I built a straight line tracking tone arm in 2012 and am looking for someone to test it. Since I am only interested in the ultimate High-End design, the tester would have to have matching High-End equipment and "golden Ears". I have a very good turntable but the rest of my audio gear is mediocre. I enjoy listening to music as played back by my own tone arm but don't have the final word on its quality due to a high frequency hearing loss.
I can't help concerning the single frequency test record but I have a question:
Since in a straight line tracking tone arm, the geometrical relationship between the stylus and the groove is always the same, why do you need to conduct tests at different locations on the LP?
Sincerely,
Ralf
Hi Ralf. I have followed your mechanical straight line tracker build in Vinyl Addict's (sp) thread. congrats for getting it to work well. I'm sure I don't qualify as a golden ear nor do I have one's system. I have hopes of building an arm much like yours and see plenty of opportunity for my build NOT to be tangent. My thinking is that a bearing slip or bind, a pull from the cartridge lead wires, or a surface defect anywhere along the path would cause mismatches between channels that should be visible. I did a similar thing to align tape heads by observing the output on my oscope and a test tape... just watch the difference between the channels and adjust. Just need the LP equivalent of that test tape. Well, congrats again and best of luck finding someone to test your tonearm 🙂
Hello pcb121055
Does that mean that you intend to build a pivoting arm?
And thanks for the kind words.
Sincerely,
Ralf
Does that mean that you intend to build a pivoting arm?
And thanks for the kind words.
Sincerely,
Ralf
Ha ha... no I plan to build a tangential arm it's just that I fully expect imprecision. I know the goal is to be tangent but there will be force applied to the cartridge-end of the wand by the stylus and the intended reaction will be movement at the carriage-end but that's not going to happen perfectly. there will be deflection due to slop in whatever build method is used and perhaps this deflection will vary as it moves across the LP. I wanted to see that. Just quality control 🙂 also, i have seen noone remark about their vertical or horizontal resonance settings nor the linearity of any arm/cartridge combo. fundamental knowledge in my mind so I want to chase it myself.
Hello pcb121055
I see how that was intended to be read.
I stopped referring to the subject tone arms as being "tangential" because they aren't. The groove, being a spiral, crosses the radius at an angle. This angle varies with groove pitch.
Even though I want my tone arm to be perfect, it can only be as perfect as the accuracy of a CNC machine.
I see why you want a single frequency test record now. When I worked for The Scully Recording Instruments Co. I remember observing the technicians aligning tape heads. As I understand you, you would use the test record to align your tone arm every step of the way from start to end.
It will be interesting to see what you come up with.
I finally found someone who will help me with the design of the servo circuitry for my tone arm. I expect to have it completely finished by the end of 2013. And I am already working on my final design for 2014 which is going to raise eyebrows for sure.
Sincerely,
Ralf
I see how that was intended to be read.
I stopped referring to the subject tone arms as being "tangential" because they aren't. The groove, being a spiral, crosses the radius at an angle. This angle varies with groove pitch.
Even though I want my tone arm to be perfect, it can only be as perfect as the accuracy of a CNC machine.
I see why you want a single frequency test record now. When I worked for The Scully Recording Instruments Co. I remember observing the technicians aligning tape heads. As I understand you, you would use the test record to align your tone arm every step of the way from start to end.
It will be interesting to see what you come up with.
I finally found someone who will help me with the design of the servo circuitry for my tone arm. I expect to have it completely finished by the end of 2013. And I am already working on my final design for 2014 which is going to raise eyebrows for sure.
Sincerely,
Ralf
Glad to see your project moving forward. What are the servos for? are you replacing the mechanical portion of the arm or using that for cueing and placement?
Hello pcb121055
I wanted to inform myself as to how much you read about my tone arm, but couldn't find any reference to "Vinyl Addict" on the internet.
I am quite sure that you know, that every servo controlled tone arm in the past required a minute deviation from true tangency in order to trigger the servo control. My first Tone arm from the early eighties was no exception.
In 2010 I designed a mechanical tone arm that utilized the drag of the LP to control the tangency of the tone arm. That worked, but it wasn't accurate. I then went back to the same servo control that I used in my first tone arm: a simple stepping motor driving a lead screw to control the location of the tone arm's carriage. The stepping motor was/is controlled by a Hall Effect device as shown in my original US Patent #4,722,080. My new tone arm incorporates a method of controlling its tangency with absolutely no error! That tone arm tracks at 90 degrees from start to end.
I am chomping at the bit to share that with others but I can't because I'll loose the right to apply for a patent.
Sincerely,
Ralf
I wanted to inform myself as to how much you read about my tone arm, but couldn't find any reference to "Vinyl Addict" on the internet.
I am quite sure that you know, that every servo controlled tone arm in the past required a minute deviation from true tangency in order to trigger the servo control. My first Tone arm from the early eighties was no exception.
In 2010 I designed a mechanical tone arm that utilized the drag of the LP to control the tangency of the tone arm. That worked, but it wasn't accurate. I then went back to the same servo control that I used in my first tone arm: a simple stepping motor driving a lead screw to control the location of the tone arm's carriage. The stepping motor was/is controlled by a Hall Effect device as shown in my original US Patent #4,722,080. My new tone arm incorporates a method of controlling its tangency with absolutely no error! That tone arm tracks at 90 degrees from start to end.
I am chomping at the bit to share that with others but I can't because I'll loose the right to apply for a patent.
Sincerely,
Ralf
I am impressed! that's as deep a DIY as you find. I was aware of the general perception that however the detection system worked, servo-equipped linear arms would incrementally make their way across the record but personally felt that it would eventually be such a small deviation that it would be below detection. I think I remember you saying your 1980's version was good to 0.1 degree? my recognition of your user name originally came from your tangential tracker thread. good luck on the patents! More recently, I saw your contributions to the thread about the mechanical linear arm by vynuhl.addict. being lazy at the time, i spelled this vinyl addict... sorry. not sure what a servo would do in an arm like you are building because i don't know what's under the hood but it sounds like you know what you are doing. hey... i knew you before you got rich 🙂
Hello pcb121055
Whatever I have contributed to this website, was to share and help, not to impress.
I agree with you, .1 degree is probably close enough.
By the time you design and build a "professional" tone arm, you've automatically priced yourself out of the low and mid-fi market. Doing the extra design work to turn such a tone arm into a true 90 degree tracker, doesn't cost anymore.
True 90 degree tracking has already been achieved by air bearing tone arms and tone arms like the Souther. What I don't like about the former, is their high horizontal mass and the fact that their pivots for vertical motion lie substantially above the surface of the LP. Tone arms like the Souther have a small degree of play in their carriage bearings which is probably taken up by the tone arm being deflected toward the center spindle. But beware of an excentric LP, of which there are many, when the tone arm will slop back and forth in its carriage bearings, once every two seconds.
Mistery solved.
People in the business have told me that you don't become rich in High-End Audio. For me, this is a labor of love.
sincerely,
Ralf
Whatever I have contributed to this website, was to share and help, not to impress.
I agree with you, .1 degree is probably close enough.
By the time you design and build a "professional" tone arm, you've automatically priced yourself out of the low and mid-fi market. Doing the extra design work to turn such a tone arm into a true 90 degree tracker, doesn't cost anymore.
True 90 degree tracking has already been achieved by air bearing tone arms and tone arms like the Souther. What I don't like about the former, is their high horizontal mass and the fact that their pivots for vertical motion lie substantially above the surface of the LP. Tone arms like the Souther have a small degree of play in their carriage bearings which is probably taken up by the tone arm being deflected toward the center spindle. But beware of an excentric LP, of which there are many, when the tone arm will slop back and forth in its carriage bearings, once every two seconds.
Mistery solved.
People in the business have told me that you don't become rich in High-End Audio. For me, this is a labor of love.
sincerely,
Ralf
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You could make a CD of your test signal and send this to one of the many shops which cut (single)LP's. Not even expensive...!
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Greetings, Hansrudolf
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