SMARTractor Calibration
For cartridge setup, I used the Acoustical Systems SMARTractor protractor with its Loefgren B DIN setting. The VTA (Vertical Tracking Angle, or effectively the tonearm height) was initially adjusted such that the cartridge’s body was visually parallel to the record. Then, the cartridge’s overhang and zenith (horizontal rotation in the headshell) were set using the SMARTtactor, followed by the VTF (Vertical Tracking Force) to the recommended medium of 2.0 grams, which I later increased to 2.27 grams.
P1 Phono Stage settings
On the CH Precision P1 phono stage, there is very little to adjust since I switched from its voltage MM/MC inputs to its current-sensing MC-only input. This < 100mΩ input reads the current generated by the cartridge (not its voltage), which is then amplified by a discrete transistor-based trans-impedance amplifier. The only parameter that still can be adjusted is the gain. If the sound is a little forward, the gain can be lowered and if the sound is lackluster, a little extra gain will do the trick.
The big upside of using current mode inputs (according to CH) is that this provides a superior signal-to-noise ratio compared to a conventional voltage input, better immunity, and no necessity to match impedance. The downside is that there’s little room for fine-grained optimization. For instance, the P1’s “regular” voltage inputs allow the loading/resistance value to be set between 20Ω and 100kΩ in what feels like a zillion steps (over 500, the large majority of which are in 5-Ohm increments). The fine steps make it easy to precisely dial in the cartridge while the extremes are available for helping a lackluster combination attain some zip or conversely damping an overly lively combination.
Simplicity and theoretical advantages of current sensing aside, with my current setup, the current-sensing input also provides a more satisfying sonic result. But just to be sure, I also tried the P1’s regular voltage input with the BORON. But just as I had found with the Origin Live turntable and Aidas Rainbow cartridge combo, this connection method yielded a beautifully highly-resolving, linear, and precise sound that was nevertheless comparatively a little flat and mechanical. In my experience, if the marriage works (with MC cartridges exhibiting low enough internal resistance), then the current-sensing inputs are to be preferred for its ideal balance between precision and flow.
Running In
This particular BORON review sample had already been used by two other reviewers but just to be sure, I gave it 15 or so record sides before attempting more serious listening. I realize that actual full bedding in of the cartridge might take 50 hours but that’s just not feasible for a review. In any event, my continued listening over the next months showed no notable changes in the sound.
BORON with Audio Origami PU-7
The Audio Origami PU-7 tonearm is specified to have an effective mass that works with cartridges approx. 11 – 20 grams. At 9.1 grams, the BORON is spec-wise not ideal for this arm. Ideally, I would have liked to have the heavy version of the PU-7 for this review. I contacted John Nilsen (AKA Johnnie or j7) of Audio Origami to explain the situation and he explained that these arms are made upon request and they take quite some time to build. No sample was available but Johhnie was kind enough to send me a range of headshell shims to effectively raise the effective mass by adding extra weight between the cartridge and headshell if needed.
My first impression using the PU-7 sans extra shims was that the BORON sounds super-confident, wide-open, crisp, fast, articulate, fantastically detailed, and highly communicative. It sounds fast, incisive, and accurate, and it has fantastic toe-tapping abilities. I noted a relative leanness in comparison with the high-output Dynavector 10X5 and the low-output Aidas Rainbow when used in the same PU-7 tonearm and on the same Sequel SP. But what I also noticed right away was that these two other cartridges are both several steps below the BORON in terms of refinement, precision, transparency, and openness. By the way, before I further tweaked it, the BORON may have been a little lean in the bass but it did not lack tonal saturation and this really came as a surprise. It’s not so common that a cartridge could be so open and direct, yet not at all dry or gray. This cart sure is analytical in that it is extremely revealing and there’s zero added fat or bloom, yet its fine delicacy and fluidity make it so that I cannot label it as clinical.
The Dynavector may have been more impressively “slamming” in the bass (as high output cartridges tend to do), but it could really do with some more richness and saturation, and it sounds rather rough and timbrally gray in comparison, which is no real surprise given its friendly price.
The Aidas on the other hand offers a remarkably natural and extra-deeply saturated tonality but it can’t touch the BORON’s level of detail and refinement and it also sounds dark in comparison.
At this point, I was rather impressed with the BORON, but just as with the Sequel SP, I had a small reservation concerning its voicing. I wondered, was the BORON indeed inherently relatively lean-sounding?
Fine-Tuning
As mentioned, the BORON has a rather stiff suspension, such, that the cantilever moves very little when the cartridge is lowered into the groove. With that in mind, I suspected that the cartridge might require a slightly higher VTF than specified. I checked with AVIDHIFI and they confirmed that the specified upper limit (+/-0.2 gram) is not a hard rule and that I could safely apply a little more if desired. Following more experimentation in an effort to dial in a little more bass fulness, I incrementally increased the VTA to 2.27 grams which proved to be ideal, providing a slightly richer and more solid sound without in any way diminishing its fast and spritely nature. Still, going by what I know to be possible with this arm, there was some residual lightness in the bass.
After adding the lightest of the available full-copper Audio Origami spacers (not sure of the weight as my scale can’t measure more than 5 grams) and readjusting the VTA and VTF, the balance shifted very noticeably to a weightier and fuller sound whilst still retaining its super-articulate nature and its super-communicative skills. Now, the bass filled out really nicely, pulling the cartridge into what I consider utterly neutral territory.
Ah, there we have that word again. Neutral. But is it musical? Oh boy is it ever! That is if, by musical, one means being actively engaged in the music. Let me be very clear. the BORON does this ever so impressively! It may veer more to earthy solidity than to ethereal flow, but its enthusiasm and expression simply have me playing record after record with an unstoppable tapping foot and a grin on my face. It is not, however, a sweetener, not an aid to add romance or some special sauce to make everything sound nice. That’s just not how AVIDHIFI does things. But if the aim is to achieve ideal neutrality (which it sure is for me), the BORON may well be the ideal cartridge to accompany the Sequel SP turntable.
Meanwhile, whether paired with a strictly ideal arm or not, the BORON tracks sublimely well. It doesn’t just track easily as well as I have come to expect from other MicroRidge Stylii at this price point, but I’ve actually not experienced better tracking at all. Not even from much higher-priced rivals. This cartridge simply replays anything you feed it, no matter how complex, with utter ease and without any sibilance, hardness, blur, or stress.
With some other MicroRidge styli, I found that while they tracked very precisely and delivered extended and airy treble, some of these other cartridges could also lack substance and body, not only in the bass, but also in the high frequencies and this can make for a whiteish treble. Don’t get me wrong, I love refinement, air, and subtlety and for the longest time, I have preferred these aspects over a relatively more coarse but more impactful and direct delivery. But as the years go by, I find that I now prefer for the signal to retain as much of its natural energy and impact as possible. And if obtaining more refinement, air, or fluidity means that a portion of the music’s natural drive, energy, and impact is reduced, I now prefer the more direct delivery. Here, too, the BORON delivers absolutely beautifully.
There is the remaining matter of this cartridge’s extremely stiff suspension. I found that even at 2.27 grams and with maximum anti-skate force applied, it has a tendency to skate when lowered too closely to the edge of the lead-in groove if the record is not entirely flat. If the needle is lowered just before the music groove starts, or anywhere else on the record, then there’s no problem.
In speaking with Stuart Roberson of AVIDHIFI about this, he explained that this was a conscious decision made for sound quality reasons, a calculated tradeoff for obtaining the spritely and direct sound from this cartridge by dissipating resonances rather than storing them. The company likes to take the road less traveled (or even make roads where there aren’t any) and that’s fair enough.
Of course, there is also the chance that the cart would behave more stably with a heavier arm, or with AVIDHIFI’s own arms! Alas, at this point in the review, the announced new tonearms were not yet released, hence my continued experiments with other arms. Anyway, even if this was not an ideal tonearm to cartridge marriage, it sounded really, really good! Every time I played a record, even so-so recordings, I was impressed!
Next: More Listening with PU-7 and Conclusion
