Considered to be a replacement for the well regarded AT440MLb, the new VM540ML matches many of the outgoing models specifications, albeit with a modestly higher recommended tracking force (2.0 grams versus 1.4 grams). This results in a decent tracking cartridge with a fairly balanced frequency response and an enjoyable, engaging overall sound quality.
- Very good sound quality with a more balanced frequency response.
- Bass, midrange and treble all sound strong, musical and clean.
- Decent tracking ability.
- Good build quality.
Audio-Technica began life in 1962, being established and headquartered in Tokyo, Japan. While it’s current product portfolio is full of all manner of consumer audio and broadcast items, Audio-Technica (AT) originally got its start producing solely phono cartridges for the Japanese home market. By 1969, AT had produced a number of successful cartridge and tonearm designs, including the development of their proprietary VM dual magnet phono cartridge, and soon it began exporting these products abroad.
Moving Magnet Phono Cartridge featuring a proprietary dual-magnet VM design
2.2 x 0.12 mil Nude MicroLine Diamond tip mounted on a tapered aluminum cantilever
4 mV @ 1 kHz
Frequency Response (Manufacturer):
20 Hz – 27 kHz
Channel Separation (Manufacturer):
28 dB @ 1kHz
Recommended Tracking Force:
1.8 – 2.2 grams (2.0 grams standard)
Recommended Resistance Loading:
Recommended Capacitance Loading:
100-200 picofarads/channel (includes tonearm wiring and phono preamp input capacitance)
Installation screws and washers, screwdriver, cleaning brush and lead wire set
Audio-Technica VM540ML Phono Cartridge MSRP:
Audio-Technica, VM540ML, Phono, Cartridge, Audiophile, Moving Magnet, Dual, MicroLine, Phono Cartridge Reviews – 2017
In the ensuing years, Audio-Technica has branched out into a number of other product categories finding success and acclaim particularly with its headphones and broadcast microphone expertise. As a matter of fact, Audio-Technica microphones have been selected for exclusive use at prominent events such as the GRAMMYS, The SuperBowl and multiple Summer and Winter Olympic Games. And yet, 55 years later, AT has not forgotten it’s roots and is still producing a broad array of both moving magnet and moving coil phono cartridges. Audio-Technica introduced their cartridges to the US market in the 1970s. Some well-reviewed examples of AT cartridges in the US include the AT25, AT-160ML, AT-ML170, AT440MLa (and b) and the AT-OC9ML/II.
The VM540ML that we have here is the top model in Audio Technica’s new 500 series of moving magnet cartridges. At an MSRP of $249.00, it represents a serious step up from what’s available at the $100.00 price point, let alone over whatever cart that may have been bundled with your turntable. Does the new VM540ML bring a commensurate increase in performance to warrant the upgrade? We aim to find out!
The Audio-Technica VM540ML is a moving magnet type phono cartridge and is the most expensive of the four models found in AT’s new 500 series line of cartridges. All the carts in this series feature essentially the same body shell design but are differentiated by varying types of styli. The styli are easily interchangeable so one could conceivably convert a VM540ML to any of the other three models in the line with a simple change of the replacement stylus, should you prefer the sound of a different tip. This philosophy also applies to Audio-Technica’s, higher end, 700 series as well. The design of the VM540ML is based off of AT’s proprietary, VM dual magnet design architecture. The main driver of the VM cartridge design is in its use of twin magnets (one per channel) arranged in a “V” pattern, in place of a traditional single one.
The VM540ML also features a nude diamond MicroLine stylus tip mounted to a tapered aluminum canteliever. The cartridge housing itself is made of a low-resonance polymer material. The VM540ML comes pakaged with installation hardware, a non-magnetic screwdriver, cleaning brush and a replacement lead wire set. Optionally, the cartridge is also available for purchase pre-mounted to one of Audio-Technica’s AT-HS10BK universal headshells for an additional $40.00.
For this review, the connected components consisted of: Technics SL1200 Mk 6 turntable with a KAB fluid dampened tonearm mod and a custom power supply, an Emotiva XPS-1 Gen 2 phono preamp, a Bryston BP-25 line-level preamp, a Marchand XM-44 2-way active crossover, a Marchand BASSIS parametric EQ, two Class D Audio SDS-470C power amplifiers (300 watts @ 8 ohm, 600 watts @ 4 ohm) and a Panamax M5500 power conditioner. My speakers are Bamberg Engineering Sound Labs Series 2 Monitors and a pair of sealed DIY 15-inch subwoofers. Speaker wire and interconnect cable by Blue Jeans Cable.
The Audio-Technica VM540ML was installed in an OEM Technics SL1200 head shell and was mounted using the Technics Overhang Gauge and aligned using an aftermarket alignment guide. Tracking force was set using a digital tracking force scale and anti-skate was set with the aid of the anti-skate band track of the Shure “An Audio Obstacle Course” LP (TTR-101). Tracking force was set to the optimum levels as recommended by the manufacturer, in this case 2.0 grams. The tonearm fluid damper was removed for bench testing so that tests results would be reflective of typical usage.
Immediate first impressions upon opening the shipping box and examining the contents are that the VM540ML arrives nicely packaged and seems well put together. From a build quality standpoint, the predominantly plastic and polymer construction of the cartridge is of a high standard. The act of stylus replacement seems reletivly straightforward as it’s recommended to remove the stylus when you initialy install the cartridge body onto the headshell. Upon re-installation, the stylus snaps back into the body in a reassuring manner. The cartridge otherwise presented no undue or particularily finiky installation issues.
Sonically, this is a well balanced cartridge that immediately sounds more even-handed than the Shure M97xE that we previously tested. Throughout my listening, I also noticed that the VM540ML exhibited a bit of a euphonic quality to its sound signature. Not by a huge amount, but noticable enough that it made this cartiridge enjoyable to listen to and seem like a good “all-rounder” with a wide variety of musical material. The upper frequencies, in particular, are certainly more pronounced than the Shure but, all the while, still maintaining a smooth and enjoyable presentation. It was such that massed strings were a definite joy to listen to with the VM540ML. Horns and brass also did really well through this cartridge, sounding vibrant and well placed yet not getting abrasive when the volume levels got feisty. The midrange was also very smooth sounding and still retained plenty of detail with vocals and instruments throughout the bandwidth.
On jazz vocals, in particular, I got the sense that there were more layers to the sound and it added an extra, and welcome, sense of dimension to some of my favorite LPs when I spun them. All the while, finer details were still there to be found in that sonic space. The subtleties weren’t blurred or lost within that added depth. Bass was certainly reproduced in good measure, with plenty of weight and impact, through this cartridge. Kick drums, tympani, double bass and electric bass all sounded excellent and well defined. At no point during my listening did I feel that the cartridge favored one band of the audio range over another. The VM540ML seems so reliably evenhanded in its nature that I think you’d be hard-pressed to find a genre of music that it doesn’t play nicely with.
The New Stan Getz Quartet featuring Astrud Gilberto, Getz Au Go Go, Verve LP V6-8600, 1964.
One of my favorite live jazz recordings that features Getz playing saxophone at his best, Astrud Gilberto’s beautiful distinctive voice, and top supporting talent including Kenny Burrell on guitar.
From the opening notes of “Corcovado” you are greeted with an enveloping amount of room ambience and Ms. Gilberto’s voice just flows over you like a soft, rich blanket of sound. The VM540ML treats her voice with a nice even hand, never veering into sounding overly thick or heavy allowing her unusual vocal phrasing to shine through. Getz’s saxophone sounds appropriately big and powerful out of the left channel but is still handled with the proper finesse in that I could make out all the subtler details in his playing as well.
On the track “It Might as Well Be Spring,” the double bass line is deep, solid and anchored in the center along with Ms. Gilberto’s voice. But the two are sufficiently isolated so as to not muddy up each other’s performance. The drums and cymbals are firmly in the right channel with the cymbals having just the right amount of sheen and crispness to them while the snap and reverb of the drum skins sounded quite correct and natural. The audio goodness continues with “Eu E Voco,” an up-tempo shuffle, where Ms. Gilberto sings in Portuguese (I believe). The rapid lyric delivery is so smooth and melodic but so clear that I feel that the VM540ML is giving me all the detail it can muster out of those grooves.
It’s also making me want to learn Portuguese, but that’s another story! Kenny Burrell’s rhythm guitar work, while more of a background element in this song, comes thorough sounding fully formed and rendered, complete with detectable slides down the neck and ample string detail. Listening to this album is a transportive experience and if there’s one type of music that a turntable setup must excel at for me, it is stuff like this.
Jean-Pierre Rampal/Claude Bolling, Suite for Flute and Jazz Piano, Columbia Masterworks LP, M33233, 1975.
Here we have two renowned instrumentalists, one a classically trained flutist and the other a pianist/composer with jazz leanings.
These two join forces (while adding drums and acoustic bass) to compose a suite of music that neatly flows back and forth between jazz and classical sensibilities. While listening to the tracks “Baroque and Blue” and “Javanaise,” the more linear upper end response afforded by the VM540ML was particularly appreciated. The solo flute parts came across as effortless, with a vibrant yet sweet sounding quality to them.
There was plenty of the performer’s breathing heard between notes, indicating good subtle detail recovery. The piano solos also had a vibrancy about them, with wonderfully clean ringing sounds to the notes and a good weight to the lower registers. On “Versatile” the flutist switches to a bass flute which is fleshed out nicely by the VM540ML. The deeper, now almost midrange, body to the notes was quite palpable and the change up in the performer’s breathing and mouthing was also quite noticeable.
The piano was also in its element producing clean notes that were deftly dancing around the bass flute creating a lovely sonic contrast between the two instruments.
Supertramp, Crime of The Century, A&M Records LP, SP-3647, 1974.
Probably one of a handful of “desert island” records for me. I’ve heard this album backwards and forwards and own it on multiple formats so it’s safe to say that I’m relatively familiar with it! As a whole, the LP sounded as clean and clear as I’ve ever experienced it through the VM540ML.
Imaging seemed excellent and regardless if it was Rodger Hodgson or Richard Davies at the mic, their respective voices were rendered with plenty of body and locked dead center of the soundstage. One of the notable qualities that stood out with this record was the bass. I’ve heard this record with certain carts (let alone a CD master or two) where the bass comes off somewhat shy and restrained. Not so here. After the opening intro, the bass line in “School” is nice and punchy giving the song a solid foundation throughout. Kick drum also had great impact and pace here as well.
Davies keyboard work sounded clean and rang nicely. Paired with Hodgson’s tasteful and detailed guitar work, the song came across as the proper tour-de-force that it is. This bass lushness continued in songs like “Hide in Your Shell” and yet contrasting with this abundant low end were details like the finger snaps that sounded eerily real and echoing just above my left and right speakers. The drum cymbals on this song also sounded properly fantastic, the metallic sound truly coming through most effectively. There is also a lot of varied percussion happening in this song and every type was exceedingly specific and distinct in the mix. The VM540ML spelled it all out exactly and it was all richly rewarding to listen to.
Frank Sinatra, Sinatra’s Sinatra, Reprise Records LP, R9-1010, 1963.
At the time, this was a more modern recording of some of Sinatra’s classic songs with orchestral arrangements by Nelson Riddle. On the track “In the Wee Small Hours of the Morning” the massed strings in the background are detailed and sweet sounding with excellent upper end energy and air.
They contrast well with Sinatra’s vocals being right smack in the midrange and placed forward in the mix. While I love Tony Bennett for sheer vocal power and range, Sinatra has a magnificent tonality and clarity to his voice that just comes out so well through the VM540ML. He is imaged very much in the room on this track with Riddle’s orchestra expanding nicely around him. On “Nancy” the horn section that solos in the middle of the song sounds truly vibrant without any sort harshness. The opening bassoon to “Witchcraft” sounds extremely detailed yet properly weighty for the instrument.
And Sinatra’s voice when the sings the word “Taboo” and stretches the end note, sounds so good with this cartridge. It sounds exceedingly three-dimensional. On the track “All the Way” the clarity of Sinatra’s singing is just so striking. Yet the VM540ML still gets the background details just right on this track with the sweet handling of dual flutes in the left channel and the subtle crispness of the riding cymbal in the right channel. Even though these are background elements to the song, they sound properly and completely rendered here. On “Pocket Full of Miracles” there is a nice and meaty stand-up bass line that travels through the whole performance that sounds properly deep and the children’s choir that backs up Sinatra here has a great sense of depth and dimensionality as well.
Handel, Concerti A Due Cori, Phillips LP, 6882 004.
A well-done recording of a chamber orchestra comprised of three concertos, two featuring strings and horns and one with only strings. I mentioned earlier that massed strings sounded especially good with this cartridge and this LP does not disappoint.
The VM540ML handles violins and violas from “Concerto No. 1” with a smoothness and delicacy that makes this material so easy to listen to and includes the added upper extension that, for me at least, completes the sonic picture.
The different instrument sections come across as well-defined with plenty of string detail being rendered in the presentation. The cartridge also successfully expresses the hall ambience in the recording thus adding to the depth and dimension of the entire soundstage. This album presents you with a big, reverberant backdrop which begs to be turned up in volume and then you get those great sonic detail hits of strings, harpsichord, oboes, hunting horns and bassoon that just sort of sparkle on that canvas. This music is decidedly brisk and up-tempo and the VM540ML is sufficiently light-on-its-feet to keep things moving along smartly and with complete clarity and command. This is one of those albums where you can just close your eyes and bask in the rightness of the sound as delivered by the VM540ML -nodding your head approvingly all the while.
This cartridge is most certainly a step up from the Shure M97Xe. While there are a few aftermarket stylus options for the Shure, that vary both in price and claimed performance benefits, the VM540ML is a superior sounding cartridge when compared out-of-the-box. The $150.00 price premium over the Shure is a worthwhile investment to make if you are looking for something in that price range straight away or are considering an upgrade.
Audio-Technica’s website recommends this cartridge to be considered as a replacement for the discontinued AT440MLb, which was a popular and well-regarded cartridge for many years. They both possess many similar features including the dual magnet “VM” design although the older cartridge is spec’d to operate with a lower level of tracking force (1.4 grams versus 2.0 grams). There are possibly a few readers who may be 440 owners and wondering if they should consider moving to the newer 540. I can’t make any listening comparisons between the two cartridges as I don’t have a 440 around. However, my colleague David Rich does, and he was able to take some comparative measurements from it that he will fold into the discussion in the Benchmarks section of this review.
If there is something I wish that this cartridge had, and you will likely hear me banging on about this in other cartridge reviews, is a dynamic stabilizer brush like the Shure M97xE has. A damped brush of this type, designed for the cartridge, works as good as having a damped tonearm in reducing low resonant frequencies excited by the cartridge/tonearm combination. It should be standard issue on phono cartridges of this price.
Before we move on to the bench tests, David Rich has prepared the following sidebar explaining in more detail the evolution of the 4th generation stylus.
The picture of the diamond tip (as supplied by Audio-Technica) is identical to a diamond tip that appears in a patent issued to a company in Japan called Namiki Precision Jewel Co. Ltd. (US Patent Number 4521877, June 1985). A very similar picture appears in Dynavector literature where the term “Micro Ridge” is used, which is the term Shure used for its cartridges with this shaped stylus tip.
Micro Line is a 4th generation stylus for which the only equivalent (but very different looking) is the one Fritz Gyger disclosed in US patent 4855989. Not all stylus listed as a Gyger have this unique shape. Not all spec sheets which call out a Fritz Gyger stylus are this advanced shape. You need a microscope to be certain.
Since I am citing patents, I should point out both of the stylus inventions above rely on US patent 4416005 by Van Den Hul. Some put this in the 4th generation category given the common manufacturing steps, but many do not consider the shape as optimum. I will call it generation 3.5.
A very comprehensive discussion of the evolution of stylus shapes is found in this thread including more patent citations and photos of most of them.
4th generation stylus shapes require more cuts and grinds to the diamond than 3rd generation shapes which, in turn, are more complex than 2nd generation ellipticals and 1st generation conical tips.
The Elliptical stylus was created in response to the demands of stereo while the 3rd generation shapes were developed for the short-lived RCA CD-4 quadraphonic LP. The 4th generation tips were designed for the biggest RCA flop of all, the vinyl video disc.
If you want the best phono cartridge, you need one with a 4th generation stylus.
This best site for layman which goes through the history of stylus development.
It is hard to explain the details without a drawing but the copyright is uncertain, so I am not reproducing them here. 4th generation shapes are characterized by two dimensions. The line of contact is the vertical dimension that indicates how much of the groove is being traced by the stylus. This is referred to as “wall contact” or “contact patch” in the above reference links. The reference goes on the explain the significance:
“because the total contact surface area increased, the amount of pressure per square area was substantially reduced – less pressure equals less wear on both the record and the stylus."
The second dimension is the side radius. On 4th generation cartridges this dimension ranges from about 2.5um – 4um.
"the reduction in side radius reduced distortion and improved tracking of the high frequencies."
Ok, I’m sure that someone is now banging on their screen pointing out that the best of the old 2nd generation elliptical stylus were 0.2mil or 5um. Back to the reference:
"but the elliptical only ever contacts the same small area – which can become worn – resulting in degradation in high frequencies".
The contact patch area became a big deal with CD-4 LPs which had a frequency response extending past 40kHz and that could get erased really fast.
What does this translate to in the real world? I do not have the VM540ML at my place, but I do have the Audio-Technica AT150MLx, AT440MLa and Shure V15V/MR as well as bunch of cartridges with older stylus shapes.
On the bench, these produce lower harmonic and intermodulation distortion figures than older generation shapes that I’ve tested, using the same test LPs Carlo used. This is consistent with measurements made in Audio, High Fidelity and Stereo Review magazines when the Micro Ridge (Line) first arrived in the 80s. In the measurements section, we will show direct comparison between the AT440MLa and the replacement VM540ML. The AT150MLx and Shure V15V/MR were put through the same series of tests creating a big picture view of the performance. You need to read the measurement section for more granularity on the differences.
There are dozens of cartridges (MMs and MCs) that I have used over time on close to 1000 LPs. Until proven otherwise, I would not think of purchasing a cartridge without a 4th generation stylus. The difference in mis-tracking is obvious as is the improved performance in less then well-treated recordings.
From my experience, the 4th generation stylus makes itself known most easily at the end of each side of a symphonic recording. Save for the slow movements, most parts of classical orchestral or choral works climax at the end of the movement just when the stylus has wound up in the inner groove of the LP. Why is that a big deal? Back to another expert:
“The first sounding turn of the groove of a 12" LP record has a radius of 146mm, and the last a 56mm diameter. The length of the first turn is thus 2 x π x 0.146m = 0.917 meters and the last, 0.352 meters. Given that a record turns at 33⅓ RPM, which equates to 0.556 turns per second, the velocity of the stylus within the groove is 0.509m/s (20 inches per second) on the outermost turn and 0.196m/s (8 inches per second) on the innermost. A 10kHz sinewave inscribed in the groove wall has thus a wavelength of (0. 509/10000) = 51μm on the outermost turn of the groove, and a wavelength on the innermost turn of 20μm.”
In the inner grooves the side radius must be small or the stylus will not fit and mis-track. It is unable to follow the scrunched grooves just as the movement is climaxing. Subjectively distortion is significantly degraded and clicking may be heard. When I first heard my LPs with a 4th generation stylus the world changed. That lasted only a couple years when the CD arrived. LP reproduction was still important at that time since few LPs had been reissued on CD. By the late 1980s most of my collection was on CD and my interests in LPs dropped. I was not the only one. Shure and Audio Technica saw sales plummet and with that, stylus development came to an end.
The VM540ML performs about as expected in the distortion bench tests for a cartridge with a 4th gen stylus. We document this in great detail at the end of the review. For those of you wondering what of the now mystical Shure V15/VMR (original mid 80s design), the VM540ML is as close as you are going to get, at least this side of $1000, with the exception of the Audio-Technica’s own AT-OC9MLII moving coil at $500. It outranks all of these in some THD and IM tests that are highly modulated with low frequency grooves but does not do as well in other tests.
Forget about looking at listings for NOS Shure units on eBay at crazy prices and forget trying to use a 3rd party ML stylus with an old Shure body. You have no idea what frequency response that produces. Shure makes that clear on its website.
As we will see in the measurements it is not the stylus that prevents the VM540ML from matching the best Audio-Technica and Shure produced in the late 80s, it’s the frequency response. The good news is, things have definitely improved from the last generation of Audio-Technica cartridges.
Outside of this cartridge, you would need a time machine to find a competing cart with a 4th generation stylus, flattish response and affordability.
Benchmarks were obtained by using a Technics SL1200 Mk 6 turntable, which has been modified and rewired by KAB Electroacoustics, as a testbed. The CBS Technical Labs (STR 100) test LP was used for frequency response and distortion at the standard recording level of 5um/ sec groove velocity. The CBS Technical Labs (STR 112) test LP was used for high level THD and two-tone intermodulation distortion tests. Three tone intermodulation distortion tests were performed using the Shure TTR 117 LP. A CBS Technical Labs (STR 151) test LP is used for measuring lateral (mono) frequency response.
The output, from the phono stage, was recorded digitally at 24-bit 48 kHz (to minimize groove wear on the test LPs) on a TASCAM HD-P2 digital recorder. Those results were analyzed on my computer using SpectraPLUS audio measurement software via the Lynx TWO B professional sound card. The Parasound Zphono and Emotiva XPS-1 phono preamps where used. We found the gain of the Parasound was set too high for the largest, low frequency, lateral grooves found on the CBS STR 112 and the preamp clipped. The Emotiva has lower gain and did not have this problem. In practice it is unlikely a music LP would clip the Parasound.
This chart shows the left channel frequency response directly compared to the right channel separation as well as the reverse condition. This is not an automated test. There are 116 total measurements for this graph comprised of 29 individual tones over 4 sweeps.
This first figure is the most significant for the VM540ML reflecting an improvement over the predecessor AT440MLa. The AT440MLa had a rising high end starting at 2kHz and culmination in a 6dB peak above 10kHz. You only got that result if you terminated it at the low side of the recommended capacitive 100pf which is impossible to achieve unless your preamp allowed you to change the input capacitance. With a typical 250pf load, the peak became larger to about 15kHz when it started to roll off. The LRC resonance frequency was moving into the passband.
Without external equalization this resulted in a bright cartridge. Some say the AT440MLa burns in with use and becomes less bright. It is the other way around. The user gets accustomed to the high-end push.
Audio-Technica can do flat when it wants to. Stereo Review reported that the ML170 (Stereo Review June 1989) produced “one of the flattest frequency responses we have seen” at +/-0.5dB 40Hz – 20kHz using the same CBS STR100 we use. But for some reason, achieving a textbook flat response is not always the goal for Audio-Technica. In the 80’s, the company had similar priced cartridges to the ML170 with a frequency response like the AT440MLa (the model was an Audio-Technica Signet brand MR5.0ML) tested by Stereo Review January 1988. That is within a year and a half of the ML170 test, where the same CBS STR 100 LP was used for both tests. Pricing of the cartridges was similar. The ML170 was $345.00 in 1989.The VM540ML is flatter than the AT440MLb and it can do it with the 250pf loading which is typical of the combination of the cable and preamp capacitance. ML170 level flatness unfortunately is not achieved.
For the left-channel-only groove or right-channel-only groove, the frequency response fits in a strip +0.9dB/-0.4dB from 40Hz – 6kHz with excellent matching between channels to 8kHz. Below 40Hz arm – cartridge resonance effects can enter the measurement for any cartridge. The cartridge then starts to work its way up starting at 8kHz when it is +2dB for both channels. The left channel finally moves up +4.3dB at 12kHz dropping back to -0.5dB at 20kHz. The right +2.6dB at 14kHz dropping back to -1.5dB at 20kHz. Note it is only the 7kHz – 14kHz octave that is problematic. The mismatch above 8kHz in the frequency response and channel separation may be manufacturing tolerance but it could also be that the mono (lateral) response differs from left only and right only.
Left channel grooves are the summation of the lateral (horizontal back and forth) movement and vertical (up and down) grooves. The right channel is the difference between lateral and vertical. We expect frequency response changes for the very different stylus movements left to right and up to down. Mono LPs have only lateral grooves. This is how compatible stereo was made. Stereo information is in the vertical grooves. For a full characterization you need more than left only and right only. You need response of a mono (lateral) groove. Finally, you need the vertical only modulation which will yield another pair of frequency responses.
V(Left) = V(lateral)+V(vertical)
V(Right) = V(lateral)-V(vertical)
This will make more sense if you watch the animated cutting of lateral, vertical, left only and right only grooves here.
Thus, when Vertical and Lateral move at the same frequency and velocity, in phase, a signal should only come out of the left channel. Any output from the right channel is from the fact the cartridge did not do the subtraction ideally. This fact results in the finite channel separation.
Moving on to the right channel only grooves, we see that the vertical and lateral are out of phase. Now the left should ideally have no output. From the graph above, you see below 8kHz the process is only good enough for a 20dB (10 to 1) separation. As you look at the two channels of the separation graphs (bottom of graph above), note how they deviate more at 8kHz which is when the left and right channel (top of graph) start to split.
The CBS STR 100 does not have a mono frequency response test but the CBS STR 151 does have mono, left and right. STR 151 has the RIAA emphasis placed before the cutting head, as would be the case for a normal LP would. STR 100 is flat without RIAA. Unfortunately, when testing frequency response, flat without RIAA is better. The cartridge produces the same voltage at its output pins which makes the response with a frequency change more stable. We are thus not showing the STR 151 response. Not subject to error is the difference response between Left, Right and lateral (mono) taken at the same time on the STR 151. We found virtually no difference between mono-left and left only. The same result was found for mono-right and right only. You will not get a tonal shift from right to center to left. To see this kind of match is very rare in cartridges but the AT440MLa also did it as well, perhaps indicative the dual magnet design does do something positive.
With 6 frequency response parameters locked in and tracking (the remaining two right and left crosstalk), vector algebra tells use vertical (L-R which is ambience to a 0th order) is also correlated to left only, right only and mono. Again, this is very rare in cartridges. You will get the depth of the image with the same tonal balance as the engineer intended from the master tape.
Unfortunately, with all 6 locked together everything points up at 7kHz and stays up until the conclusion of that octave at 14kHz. Come on Audio-Technica, you know how to do flat, as was produced in the ML170. The ML170 uses the same dual magnets and electronic coil design as the VM540ML. For the moment, we have to live with some brightness in the VM540ML although it is in the single octave centered at 12kHz. It is not the burn your ears off AT440MLa bright starting lower in frequency and ending higher in amplitude, but it could be state of the art ML170 flat.
At low frequencies, turntable rumble typically dominates channel separation graphs. For this reason, chart recorder graphs typically stop at 500Hz. Using the spectrum analyzer to isolate the fundamental increased resolution below 500Hz, but below 100Hz, the results are pessimistic. Let’s take a look at the spectra of some of the spot frequencies of the CBS STR 100. These are standard operating level 5cm/sec. It is interesting to note the RIAA de-emphasis improves the distortion numbers. The de-emphasis curve is down about 6dB per octave above 1kHz. The harmonics levels are higher at the cartridge output then what is shown on the spectrum analyzer. We listen after the RIAA de-emphasis is applied by the phono preamp so the distortion on the spectra is what we hear, lower than what the cartridge produces.
The left channel produced the lower crosstalk value at 21dB. What is not average is the distortion since the VM540ML has a 4th generation Micro Line stylus. You can see the fundamental tones as well as harmonic distortion. THD for the worst-case left was 0.5% at 2.0 grams dropping to 0.36% at 2.2grams. Lesser cartridges can be 5 times this value. Note the rise in the noise floor below 400Hz which is the turntable rumble. You can see how the rumble at low frequency could hide the crosstalk spur. Spurs at 60Hz and multiples of that frequency are from power line hum getting into the cartridge. Depending on the cartridges design, this can change significantly. The Technics / Shure combination produces well suppressed power supply harmonic spurs.
This graph shows measured channel separation at 5kHz to be 22 dB for the worst case left channel. The left channel also produced the worst-case distortion at 2.0% at 2 grams dropping to 1.6% at 2.2grams. This was one of the only measurements that were not close to state of the art, but it appears to be some sort of strange distortion peak centered at this frequency. 2kHz was only a couple tenths higher than the best (see below) and as we will see next, distortion came down at 10kHz. With an elliptical stylus at 5kHz, this can run over 5% with a continued increase as the frequency goes up. Third generation stylus would still produce worse performance than what you see here.
Distortion at 10kHz takes into account only the 2nd harmonic but that is the dominant one. The results are again state of the art at 0.9% in the worst case right channel at 2.0grams with only a slight reduction at 2.2grams. This is state of the art and again a result of the stylus shape.
This graph shows measured channel separation at 20kHz to be 15.5 dB on the worse right channel. Less expensive cartridges can produce very low channel separation numbers above 15kHz. As an absolute measurement, this is unimpressive for a state of the art moving magnet cartridge in the 1980s. I cannot report distortion with the 2nd harmonic well outside the audio band.
We are using an unorthodox test for the low frequency resonance. This is the resonance excited by groove noise and rumble. We do not measure the resonance with spot frequencies. The spectrum above is typical of the sub-sonic response you will get when you play an LP. The FFT band size is 0.4Hz for a 64k FFT at a sampling rate of 48kHz spreading the resonance out. The trade for the increased down force requirements of the VM540ML (1.8 grams – 2.2grams) from the AT440MLa (1.0 grams – 1.8 grams) was conjectured to be a higher resonance frequency (above record warp frequencies) and lower peak resonance in today’s higher mass arm. That does not appear to be the reason. The resonance frequency moved from only 7Hz to 7.5Hz. The Q of the resonance is a still high at 3. Fluid damping reduces this significantly. An easy add on from KAB for the Technics SL1200 but rare for other turntables.
If improved low frequency resonance was not the goal for the VM540ML, we are left to assume the issue was higher friction found in cheaper tonearms produced today. I should point out that the last generation top dog Audio-Technica AT150MLx has a much lower resonance frequency and much higher Q than what you are seeing here. The AT150MLx required a silicon damper to be usable on warped records.
It is time to show you the results from all the distortion tests we did with the AT540ML. All our distortion measurements were taken at 2.0 grams and 2.2 grams for the VM540ML. In addition, we tested the last generation AT440MLa. Some tests are better with the VM540ML at 2.0 grams and some at 2.2 grams. We recommend the lower downforce given the mixed results for the VM540ML at is maximum 2.2grams.
We did measurements of the VM540ML and the predecessor AT440MLa. The AT440MLa has a minimum tracking force of 1.3grams and it does well. Moving to 1.8grams is state of the art with the AT440MLa and yes, we have a complete chart for the Shure V15/VMR which we will publish separately. Without the 4th generation ML stylus, you are not going to see numbers like this. This can be corroborated by scanning measured data in issues of High Fidelity / Stereo Review / Audio before the ML stylus appeared. Hi Fi News has these kinds of figures on its website for more modern cartridges. The distortion in Hi Fi News is down 8dB from the 5cm / sec we used here.
Looking at the Hi Fi News distortion measurements, including the AT440MLa, we again conclude it produces state of the art distortion performance.
The VM540ML has the cost of a downforce increase to 2.0 grams. No significant distortion performance reduction is noted in the chart above. We again remind you though that, as nice as it tracks, the AT440MLa frequency response renders it un-usable without a filter to reduce the high frequency lift. State of the art tracking with an ear-bleeding bright high end does not qualify as a super cartridge. As we saw above, things are better now if not perfect.
A cartridge’s output is proportional to the groove velocity not the amplitude. For a constant voltage output, groove size grows as the frequency goes down. Without the RIAA emphasis which attenuates at low frequency the groove width and depth vary by more than 1000 to 1. The harmonic distortion measurements are thus, typically taken, at a constant groove velocity. In our tests, the peak velocity is 5cm / sec above 500Hz. At low frequencies, the CBS STR 100 backs off the velocity.
To the left is a photo of CBS STR 112, a distortion test LP. You see 200Hz and 400Hz grooves required to produce 5cm / sec velocity. These are modulated laterally (mono) up do a distance of 90um. The STR 112 also has grooves that are vertically modulated. These go to 50um. Any larger and the cutting stylus would punch through the lacquer.
We will now show spectra of these extremely wide grooves. The measurements were done at the “Tracking force – optimum setting” of 2.0 grams.
Above is the spectrum of 100Hz lateral groove at 50um. THD is 0.8%. We see 2nd and 3rd harmonics.
This spectrum is a 300Hz lateral groove at 88um. The worst right channel is 1.1%. You see additional higher order harmonics which decline monotonically.
At low frequency, the stylus shape is not what dominates. The design of the cantilever, magnet and rubber assembly are the keys to getting this performance. As an example of this, the Audio-Technica AT-OC9/MLII performs better in these highly modulated groove tests, for reasons that are not clear, using information published in Hi Fi News and Record Review and independent measurements by John Elision in a news group.
High frequency distortion is lower in the VM540ML despite the same stylus. The increased mass from the moving coils is responsible for this.
Above is the rarely reported distortion in the vertical direction. For a 50um groove at 100Hz, the distortion is 3.9% which is more than 4 times the lateral. Vertical distortion differences from lateral are a secret cartridge manufactures would not like you to see. The mechanics of moving up and down are different from side to side.
Here is a 300Hz vertical spectrum for a groove 44um long. At 2.7%, this is double the lateral. Note the significant number of harmonics all the way out to 5kHz, although they are low in level at that frequency thanks to the RIAA de-emphasis.
To the large grooves now at 400Hz, we add a 4kHz tone set at 2.5 cm/sec which will produce a tone at -6dB standard recording level. This is tiny at 2um because the frequency is up 10x and as we pointed out above, groove size goes down with frequency for constant output. The small 4kHz frequency groove is being tossed around like a tiny ship in a storm. Will it sink?
This is a 22um groove at 400Hz. THD at 400Hz is 0.8%. 4kHz is also at 0.8%. The wild stylus movement has not moved this up significantly. The IM spurs at 3.6kHz and 4.4kHz tell a different story. The RMS sum of the spurs is 6.3%. We do not have a cartridge expert to explain why the interaction of the two grooves results in such high IM. The 2.2 grams numbers are about the same as you can see from the chart above. Cartridges with elliptical stylus can have 4 times the IM and generation 3 stylus will split the difference. We do not understand the noise lift in the right channel.
Moving up to a hurricane sized groove of 88um lateral, what happens to our little 4kHz groove? The IM distortion is now up to 25%. Yes, this is audible. It is especially unpleasant if you high-pass filter the 400Hz tone and listen only to the 4kHz tone. Note the fundamental level has dropped 6dB but the groove size is unchanged. Our 4kHz ship has gone under the sea. The 4kHz THD is up to 1.3%, but that is meaningless with the drop in level. THD for the wide groove at 400Hz is still 0.8% but we have lost 4kHz.
No noise increases in the right channel, which we saw in the lower level 22um spectra above, can be seen. I have no understanding of the noise rise in the 22um spectrum. The AT440ML at 1.8grams turned in a lower 11% which is one of the few tests where the two cartridges differed significantly, but the spur was also reduced in level by 2dB, so the cartridge is mis-tracking. Once you reach that state, differences have little importance. This result shows that cartridge and stylus development still have a long way to go.
Having tossed our little 4kHz groove back and forth, lets punish it further by going up and down.
This is a 22um vertical grooves test for 400Hz and with a vertical 4kHz again at 2um. The distortion is about the same as the lateral. THD at 400Hz is 0.8%, 4kHz is up a tad at 0.9% along with the IM at 6.8%. Increasing the downforce to 2.2grams makes things slightly worse. Lateral showed little change. Next, we move our little 4kHz ship up and down at twice the height.
This is a 44um vertical grooves test for 400Hz and with a vertical 4kHz again at 2um. All numbers have increased from the 22um test. 400Hz THD is 1.4%. 4kHz THD is 1.2%. The IM is significantly higher at 18.5% worse than the lateral. We also see a 1.2dB increase in the 4kHz amplitude. I have no idea why it went up given the constant groove size, but this is clearly an indication the cartridge is in distress. Again, we have mis-tracking here. The results at 2.2 grams were equal or slightly better. This is a reverse from the 22um result. Again, this split result points to using the lower 2.0 gram setting. The maximum lateral is 90um wide, a number you cannot do vertically without the cutting stylus having a China syndrome. Given the 2X groove, the IM lateral is higher at 25% as we discussed above.
We move now to the Shure TTR117 trackability test LP. While it is a Shure test LP, it turns out that Audio Technica cartridges with Micro Line stylus perform close to or exceed the Shure V15/5MR performance on the TTR117. Indeed, the AT440MLa has about the best performance we have seen, as can be seen from the table. The TTR 117 LP tests harmonic and intermodulation distortion. It has 3 tones at 200Hz, 2.1kHz and 17kHz.
The fundamental frequency spurs and the harmonics of the 200Hz and 2.1kHz tones are shown above 17kHz harmonics are out of band. Level 1 has the 200Hz tone groove velocity at 1.0cm /sec, 2.1kHz is at 4.8cm / sec and 17kHz is at 4.4cm /sec. The RIAA de-emphasis changes the relative levels of the test tones in the spectra. TTR 117 has only a lateral (mono) test and no vertical. The LP has 6 levels. They go up 7dB for the top Level 6 test. At Level 6, groove velocity for the 200Hz tone is at 2.2cm/sec, 2.1kHz is at 11cm / sec and 17kHz is at 10cm.
The IM tests above with the CBS STR 112 had much larger low frequency levels. With the TTR 117 it is reversed. At Level 6, the 2.1kHz and 17kHz are at twice the standard recording level of 5cm / sec used in the THD tests above. This makes the THD of the tones of interest but, as with the IM tests above, the harmonics may be increased by the presence of other tones in the grooves thereby increasing the stylus excursion. With two tones on the test track with the same groove velocity, the composite signal at the cartridge output (before RIAA de-emphasis) is twice the single tone level. A little more with the 200Hz tone added in. Combined, this is a hot groove, but since it is mostly high frequency, it is not very wide.
For the VM540ML, changes in IM and THD were small moving from Level 1 to Level 6 so we will show only the Level 6 spectra. The location of the signals, harmonic distortion and IM of the Level 6 test are shown above. Mixing of the 200Hz tone with the 2.1kHz tone results in intermodulation sidebands at 1.9kHz and 2.3kHz. Mixing of the 400Hz harmonic of the 200Hz tone with 2.1kHz gives rise to the 1.7kHz and 2.5kHz sidebands. The same thing happens between the 2.1kHz tone and 17kHz tone with sidebands at 12.8kHz, 14.9kHz, 19.1kHz and 21.2kHz. All the fundamental tones are lateral grooves only for the TTR 117.
THD for the 200Hz tone is 2.0%. This is close to the results we got for the very large grooved low frequency test we showed above. It is the 2.1kHz and 17kHz mixed into the same groove that has pushed the 200Hz harmonics up. The 2nd harmonic (400Hz) is at 1.8% with the 3rd harmonic (600Hz) at 0.7%. The THD of the 2.1kHz tone is 0.8%. This is an impressive result given the level of this tone and the other tones in the groove. The 2nd harmonic (4.2kHz) is at 0.7%. Note the IM spurs around the 2nd harmonic are almost as strong as the fundamental. This is typical of the TTR 117 with super tracking cartridges that have low levels of harmonics in this test. Perhaps the RMS sum of the 3 closely spaced tones should be the value of the 2nd harmonic which would take it to 1.2%. The 3rd harmonic (6.3kHz) at 0.3%. No THD measurements for 17kHz since the harmonics are out of band.
The IM spurs around 2.1kHz are at similar levels. These are at intervals of 200 Hz around 2.1kHz. 1700Hz is 0.5%, 1900Hz is 0.47%, 2300Hz is 0.37% and 2500Hz is 0.41%. The RMS sum of the 4 spurs is 0.8%. The IM spurs around 17kHz are at much higher levels. These are at intervals of 2100 Hz around 17kHz. 12.8Hz is 4.7%, 14.9kHz is 16.7% 19.1kHz is 15% and 21.2Hz is 0.4%. The RMS sum of the 4 spurs is 23% which indicates the 17kHz is not tracking. The 17kHz fundamental level was at the expected value. It did not reduce despite the high IM distortion. Increasing to 2.2grams reduced the number by only 2% but the IM between 200Hz and 2.1kHz actually increased slightly from 0.8% to 1.1%. The AT440MLa at 1.8 grams turns in about the best number we have seen at Level 6, but it is still 13%. We still have more room for improvements in cartridges. Level 1, which has the tones 7dB lower than Level 6, but it did not produce much better numbers with the AT540ML at 2.0grams. On Level 1 the 17kHz IM with 2.1kHz was still very high at 19.4%. The 2.1kHz IM with 200Hz moved from a low value of 0.8% for Level 6 to 0.7% for Level 1.
So, why did we do all this? Over 100 measurements across the VM540ML and AT440MLa went into the chart above. Producing 100 spectra from which we cut it down to 10 for this presentation. A repeat of it all for a Shure V15/VMR will be shown later. The answer is we wanted to know if you could purchase a state of the art tracking cartridge at $250.00. The answer is yes, and you are now free from scanning eBay for 1980s cartridges. Yes, we will keep testing cartridges to see if something better is out in the wild. What we want is this tracking but flatter frequency response in the octave around 12kHz. On the other hand, why wait? What else in audio can produce state of the art performance on the test bench for $250.00? Finally, nothing prevents you from having multiple cartridges in different shells. When your cartridge with flatter frequency response mis-tracks in the inner grooves of a 20th century symphony, take that shell out and put the VM540ML in.
THE VM540ML gets so much right that, for $250 bucks, it’s hard to go wrong with this cartridge. Buy it.
- Balanced frequency response.
- Very dimensional sound quality.
- Excellent performance for the price.
- Great build quality.
- Wish it had a Shure-type stabilizer brush
The Audio-Technica VM540ML is a cartridge that saw a lot of use during our time together. In fact, it stayed on my tonearm a good long while, not just because I had to submit it to an extended barrage of merciless testing (which I did), but because I could not find a compelling reason to swap it out. With album after album, not once did the VM540ML turn out a disappointing performance. So enjoyable was it to listen to. Its balanced frequency response and dimensional rendering ability make this cartridge an appealing go-to choice, if you want superior sound for a relatively modest investment or are upgrading from the $100.00 price point.
In many respects this cartridge is a bit of a “sleeper” in that it doesn’t appear visually flashy or have any “extra-special” features that draw any sort of curiosity towards it. What it does have, however, is excellent engineering and design. The dual-magnet architecture, laminated cores and nude MicroLine stylus are features that actually matter and collectively create a bottom-line performance that would be enviable in more expensive cartridges. The tracking force may be slightly higher than the discontinued AT440MLa (or b), but I doubt you would find that detrimental at all in real world usage. What you will notice, is the exceptional sound quality for the money and the grin on your face when you listen to your favorite music.
If you are looking for a top-notch, daily-driver cartridge and $250 bucks is in your budget. Buy this cartridge, you won’t regret it. Sometimes, as the saying goes, “Less is more.” In this case though, a little bit extra gets you way more than you bargained for. The VM540ML is highly recommended.