I just tuned in to see what was happening on these pages regarding our newest "baby", and no surprises - there's a lot of opinion out there! Some of it is slow and considered (my preference) while some other ideas, while sincere I'm sure, go askew from the technical mark. Without appearing rude, I will say I just won't have time for on-going discussions about these things, and I also don't think this is the place for "advertising", as such; however, I do think it's important to set a few mis-conceptions to rest, or at least give our rationale behind what we've done.
The first item that needs a little attention is this business if tonearm mass. A few (for example, SirSpeedy, who seems to have a high rate of typing speed capability)have suggested that the Phantom appears to be an enlarged 2.2/SME combo. Looks can be deceiving, and in this case, is entirely wrong. While it's true the Phantom is larger than the 2.2, it's also true that the Effective Mass (not the same as the static weight of the parts) is very nearly the same as the 2.2, but with even better damping control.
In tonearms, it is a mistake to confuse the sheer size of something and equate that with performance. It's Effective Mass (the mass as seen by the stylus tip) that's really important here, not the physical appearance. In truth, the difference in static weight between the 2.2's armwand and that of the Phantom is a mere 5 grams; yet, the Effective Mass remains low, as evidenced by measurements of resonant frequency and Q.
We did want to accommodate heavy cartidges, it's true, but not at the expense of lighter-weight ones. In good cartridge design, the static weight of the body (tare) will indicate the compliance; thus, a heavier moving-coil cartridge should have a somewhat lower compliance than a lightweight moving-magnet, for example. This is necessary so that the all-important resonant frequency can be preserved at the right place and with the lowest amplitude, Q.
The 2.2 was a good performer in this regard, but the Phantom will handle a somewhat wider range of cartridges, and, from the tests I've made with all available cartridges I can get my hands on, with the correct LF performance in the resonance region of 8-12hz. There has been some concern the Phantom won't handle the lighter weight cartridges (Tranfiguration, etc), but in fact it will work just fine. I even have an old copy of the ADC-XLM, a fly-weight moving-magnet from the 70's. This is easily balanced at 1.25 grams, and the resonant frequency is at the correct 9hz point, and with an extremely low Q. (The ADC cartriges were, and are, remarkable performers. It's only too bad they're not still in business today - who knows what they might offer).... Anyway, hope that sheds some light on the Mass issue.
Next is the issue of pivot design. Again, SirSpeedy wishes we could have made a bearing-less design using magnets. Not a bad idea, but I'm not sure how it could be pulled off successfully. As Jameswei said in 03-09-05, there would be resonance challenges to deal with. Also, it depends on the bearings and quality. In truth - and this can be demonstrated - a properly designed bearing can have vanishingly low friction, and in the case of a unipivot, this can be almost non-existant. But the bearing material is just as important as the design itself, and cheaper materials just won't do the job. Tungsten carbide and sapphire/ruby jewels come to mind as the supreme choices for a bearing (why else would Rolex and other fine watches use ruby if it weren't for better performance? The cost difference is insignificant).. In our experiements, steel and stainless steel components had unacceptably high friction.
So why not use magnets for both horizontal and vertical? Maybe some day, but at the moment, I can't think how this would be done without a LOT of compromise and unnecessary complexity. If someone is concerned about friction in a unipivot bearing designed as I'm suggeting, then they're barking up the wrong tree and are worried needlessly about a vanishingly low friction to begin with.
Nautral Balance that is achieved with the stabilizatin system Magneglide(tm) is not "arketspeak" either, as was suggested in one of the posting. The term "Neutral Balance" is a real, physics-based concept that simply states a system in neutral balance will not have a favored rest position. For the Phantom, this means that the tracking force is much less dependent on the arm's pivoting position (over warps, etc) than with the 2.2 and all other unipivots I know about which MUST have a restoring force (stable balance) in order to stand upright. This isn't a gimmick: it's a true concept that works. In addition, the Magneglide(tm) system allows the arm to pivot in the correct plane of the stylus tip (also achieved with SME and other well-designed gimble-bearing arms), rather than the undesirable plane of motion of the armtube itself, which includes the 2.2.
And the last area I'll have time to comment on in this posting is again, our friend SirSpeedy (not picking on him, really, but he has the most comments and so has had more opportunities to perhaps be misunderstood ..). In 03-06-05, he says that "A true uni-pivot should NOT be restricted in movement, IMO!" Well, in the area he may be thinkin of, normal lateral and vertical movement, that's correct; however, we do NOT EVER, under ANY circumstances, want a tonearm - any tonearm - to rotate about it's longitudinal axis! Period! In other words, we don't want an arm which will wobble,changing azimuth, as it so desires. A fixed-bearing arm takes care of this automatically, and unipivots require the use of a low center of gravity (lowered counterweight or side weights) to achieve this. But a unipivot with this approach cannot, so far as any theory I can see allows, ever hope to achieve the desirable state of Neutral Balance during play. That's where the Magneglide(tm) system comes in: it allows the arm to be designed independently of any rotational restoring force (lowered counterweights or side weights) and then uses the magnetic stabilizer to "lock-in" the rotational position of the arm to the desired setting. As a by-product, the Magneglide(tm) system allows easy, repeatable azimuth adjust (but NOT on the fly, please...) and forces the arm to pivot in the correct plane of the stylus tip.
Glad there's so much interest in our new arm. I worked very hard on this for two years, and it was designed from the beginning to be an improvement over the 2.2, not just another version of the same thing. Forums such as this are good to compare notes, and I'll always pay attention to issues and problems (which we hope don't occur) when they're brought up. Already I have noticed, for example, the difficulties in mounting the Phantom (or the 2.2, for that matter) to the excellent HR-X turntable. So, Harry Weisfeld and I are collabering on this, and with his removable armboard version of that turntable, I'm designing a drop-in mounting board and a 1/2" longer interchangeable armtube that is designed for use with larger diameter platters like this. And we'll also be offering a damped cartridge headshell spacer to use when a particularly short cartridge and/or turntable platter requires the arm to be lowered more than the combination will allow. (I was not sure people would like a spacer, but I must report that the night I first listened to this, the system never sounded better! Maybe it was just one of those "good hi-fi" nights, but in any case I can honestly report that the damped spacer, (in medical termss) "First, does no harm!" In fact, there's good reason to presume that the addition of a suitable - but rigid - damping material between any headshell and a cartridge will provide constrained layer damping for improved resonance control.
So, as I look back at this, the comments I've offered may, in spite of my efforts not to advertise, may sound like more ad copy. Tried not to, but it's hard not to write convincingly without doing so, I guess. Also, the posting is a LOT longer than I anticipated, and my wife is calling me on the phone, asking when I'm coming home for dinner!
So, I enjoy the letters, folks - even the ones with technical concepts that are slightly to the left of center. Mostly, it's about the listening, as a few sage contributors have already said. I hope you'll agree that's what it's all about!
Happy Spring to all,
Bob Graham
The first item that needs a little attention is this business if tonearm mass. A few (for example, SirSpeedy, who seems to have a high rate of typing speed capability)have suggested that the Phantom appears to be an enlarged 2.2/SME combo. Looks can be deceiving, and in this case, is entirely wrong. While it's true the Phantom is larger than the 2.2, it's also true that the Effective Mass (not the same as the static weight of the parts) is very nearly the same as the 2.2, but with even better damping control.
In tonearms, it is a mistake to confuse the sheer size of something and equate that with performance. It's Effective Mass (the mass as seen by the stylus tip) that's really important here, not the physical appearance. In truth, the difference in static weight between the 2.2's armwand and that of the Phantom is a mere 5 grams; yet, the Effective Mass remains low, as evidenced by measurements of resonant frequency and Q.
We did want to accommodate heavy cartidges, it's true, but not at the expense of lighter-weight ones. In good cartridge design, the static weight of the body (tare) will indicate the compliance; thus, a heavier moving-coil cartridge should have a somewhat lower compliance than a lightweight moving-magnet, for example. This is necessary so that the all-important resonant frequency can be preserved at the right place and with the lowest amplitude, Q.
The 2.2 was a good performer in this regard, but the Phantom will handle a somewhat wider range of cartridges, and, from the tests I've made with all available cartridges I can get my hands on, with the correct LF performance in the resonance region of 8-12hz. There has been some concern the Phantom won't handle the lighter weight cartridges (Tranfiguration, etc), but in fact it will work just fine. I even have an old copy of the ADC-XLM, a fly-weight moving-magnet from the 70's. This is easily balanced at 1.25 grams, and the resonant frequency is at the correct 9hz point, and with an extremely low Q. (The ADC cartriges were, and are, remarkable performers. It's only too bad they're not still in business today - who knows what they might offer).... Anyway, hope that sheds some light on the Mass issue.
Next is the issue of pivot design. Again, SirSpeedy wishes we could have made a bearing-less design using magnets. Not a bad idea, but I'm not sure how it could be pulled off successfully. As Jameswei said in 03-09-05, there would be resonance challenges to deal with. Also, it depends on the bearings and quality. In truth - and this can be demonstrated - a properly designed bearing can have vanishingly low friction, and in the case of a unipivot, this can be almost non-existant. But the bearing material is just as important as the design itself, and cheaper materials just won't do the job. Tungsten carbide and sapphire/ruby jewels come to mind as the supreme choices for a bearing (why else would Rolex and other fine watches use ruby if it weren't for better performance? The cost difference is insignificant).. In our experiements, steel and stainless steel components had unacceptably high friction.
So why not use magnets for both horizontal and vertical? Maybe some day, but at the moment, I can't think how this would be done without a LOT of compromise and unnecessary complexity. If someone is concerned about friction in a unipivot bearing designed as I'm suggeting, then they're barking up the wrong tree and are worried needlessly about a vanishingly low friction to begin with.
Nautral Balance that is achieved with the stabilizatin system Magneglide(tm) is not "arketspeak" either, as was suggested in one of the posting. The term "Neutral Balance" is a real, physics-based concept that simply states a system in neutral balance will not have a favored rest position. For the Phantom, this means that the tracking force is much less dependent on the arm's pivoting position (over warps, etc) than with the 2.2 and all other unipivots I know about which MUST have a restoring force (stable balance) in order to stand upright. This isn't a gimmick: it's a true concept that works. In addition, the Magneglide(tm) system allows the arm to pivot in the correct plane of the stylus tip (also achieved with SME and other well-designed gimble-bearing arms), rather than the undesirable plane of motion of the armtube itself, which includes the 2.2.
And the last area I'll have time to comment on in this posting is again, our friend SirSpeedy (not picking on him, really, but he has the most comments and so has had more opportunities to perhaps be misunderstood ..). In 03-06-05, he says that "A true uni-pivot should NOT be restricted in movement, IMO!" Well, in the area he may be thinkin of, normal lateral and vertical movement, that's correct; however, we do NOT EVER, under ANY circumstances, want a tonearm - any tonearm - to rotate about it's longitudinal axis! Period! In other words, we don't want an arm which will wobble,changing azimuth, as it so desires. A fixed-bearing arm takes care of this automatically, and unipivots require the use of a low center of gravity (lowered counterweight or side weights) to achieve this. But a unipivot with this approach cannot, so far as any theory I can see allows, ever hope to achieve the desirable state of Neutral Balance during play. That's where the Magneglide(tm) system comes in: it allows the arm to be designed independently of any rotational restoring force (lowered counterweights or side weights) and then uses the magnetic stabilizer to "lock-in" the rotational position of the arm to the desired setting. As a by-product, the Magneglide(tm) system allows easy, repeatable azimuth adjust (but NOT on the fly, please...) and forces the arm to pivot in the correct plane of the stylus tip.
Glad there's so much interest in our new arm. I worked very hard on this for two years, and it was designed from the beginning to be an improvement over the 2.2, not just another version of the same thing. Forums such as this are good to compare notes, and I'll always pay attention to issues and problems (which we hope don't occur) when they're brought up. Already I have noticed, for example, the difficulties in mounting the Phantom (or the 2.2, for that matter) to the excellent HR-X turntable. So, Harry Weisfeld and I are collabering on this, and with his removable armboard version of that turntable, I'm designing a drop-in mounting board and a 1/2" longer interchangeable armtube that is designed for use with larger diameter platters like this. And we'll also be offering a damped cartridge headshell spacer to use when a particularly short cartridge and/or turntable platter requires the arm to be lowered more than the combination will allow. (I was not sure people would like a spacer, but I must report that the night I first listened to this, the system never sounded better! Maybe it was just one of those "good hi-fi" nights, but in any case I can honestly report that the damped spacer, (in medical termss) "First, does no harm!" In fact, there's good reason to presume that the addition of a suitable - but rigid - damping material between any headshell and a cartridge will provide constrained layer damping for improved resonance control.
So, as I look back at this, the comments I've offered may, in spite of my efforts not to advertise, may sound like more ad copy. Tried not to, but it's hard not to write convincingly without doing so, I guess. Also, the posting is a LOT longer than I anticipated, and my wife is calling me on the phone, asking when I'm coming home for dinner!
So, I enjoy the letters, folks - even the ones with technical concepts that are slightly to the left of center. Mostly, it's about the listening, as a few sage contributors have already said. I hope you'll agree that's what it's all about!
Happy Spring to all,
Bob Graham