I first heard about their ceramic headshell last year when I was updating my turntable setup with a vintage Micro Seiki BL-91 turntable and a GrooveMaster 3 tonearm.
"Ceramics? Isn't that what they use in pottery and fine china?" I thought. Nevertheless, Jam Somasundram, a friend and turntable specialist, insisted I try Korf Audio's HS-A02 headshell. An engineer and audio designer of some renown, I met him when I reviewed the Pass Labs HPA-1 Headphone Amplifier (HERE) that he designed. I became better acquainted with him while reviewing his Quadratic Audio MC-1 Moving Coil Transformer (HERE).
For my edification, Jam lent me a spare Korf Audio HS-A02 headshell from his extensive collection of turntable accessories to try out. After receiving it, I noted its much lighter weight compared to the Audio Creative HS-01 Titanium Headshell that came with the Audio Creative GrooveMaster 3 Tonearm (HERE) that I reviewed and, eventually, purchased.
I used the Korf HS-A02 Ceramic Headshell to compare the Gem Dandy PolyTable Signature (at the bottom of the photo) with my reference Micro Seiki BL-91, applying small strips of masking tape to it with color-coded markings for the screws and finger lift placement to shorten cartridge realignment-related time lag when swapping turntables.
I was impressed with the Korf HS-A02's sensitivity and performance with several cartridges, including the Goldring Ethos SE that was in for review. Using it to compare two turntables in my review of the Gem Dandy PolyTable Signature, I found its great ability to convey the differences between it and the Micro Seiki BL-91 turntables extremely useful, as noted in the following passage:
"I was immediately struck by how both turntables rendered the vitality of vinyl with sublime imagery, detail, and balance," I wrote. "The differences were subtle, but overall, the PolyTable Signature played slightly warmer and organic sounding through the midrange and a scintilla softer in the highs." (You can read more HERE.)
A Screwy Hiccup—and Quick Fix—with an Ortofon Cartridge
That said, I also noticed that the Korf HS-A02 was a tad thicker than my other headshells, making the installation of my reference Ortofon MC Quintet Black S cartridge a bit more cumbersome, as the tiny screws that came with it were too short, and others were too long (rather than exit out holes to either side of the cartridge like the Goldring Ethos SE I reviewed, with the Quintet screws bore directly into its body, restricting the usable length).
I reached out to Alexey Korf, owner of Korf Audio, and he emailed back, "The (Korf) shell is exactly 3 mm thick. I use 6 mm screws with my Ortofon Kontrapunkt b, (and) they fit perfectly." Ortofon didn't carry that length, so I special ordered a set of 6 mm phono cartridge screws from Amazon.
After that, setting up the cartridge was a snap: holding their lightweight brass lift atop the headshell, one at a time, I inserted, then screwed them into place. I plugged the headshell into the GrooveMaster 3 Tonearm, rotated the securing cuff, and went about aligning the cartridge using the Korf protractor and adjusting the tracking force (VTA, anti-skating, and azimuth (which is adjusted on the GrooveMaster, itself, as the HS-A02, as a solid unibody, cannot be adjusted via the cartridge itself) were previously set).
Now, the Korf HS-A02 worked hand in glove with my Ortofon MC Quintet, bringing out more detail in its presentation than I'd remembered. I continued using it for reviews and personal use. After I procured a second Korf HS-A02 headshell review sample from Alexey, I was able to conduct A/B comparisons between the Goldring Ethos SE cartridge and my Ortofon MC Quintet Black using identical headshells for my review of the former (you can review that HERE).
But what made it so special, I wondered.
No Porcelain Pony - It's an Alumina Ceramic Thoroughbred
"Korf headshells are made of alumina ceramic," Korf wrote on their website. "Why did we choose it? Studying dozens of headshells, we discovered that their rigidity (stiffness) impacts the sonics most. This led to a question, which material can provide the best rigidity at minimal weight? Turns out, ceramics have very little competition here.
"We chose alumina ceramics because it is the lightest and one of the strongest," he continued. "Looking at Young's Modulus (a measure of stiffness) of aluminum and alumina ceramic, the latter is almost four times as rigid while being only a third heavier.
"To deliver a high precision monolithic (one piece) ceramic headshell, we have partnered with the British ceramics specialist IPS. Nobody else has this ability—this is why Korf HS-A02 is the world's only one-piece ceramic headshell."
Digging a little deeper, I accessed an article on IPS's website. "Thanks to its alumina material, the HS-A02 Ceramic headshell has twice the rigidity of the next best product in the market," it read. "Thanks to the advances in ceramic production which we have developed, it is comprised of one single piece without any connectors or components to compromise its design. It also has a reinforcing rib which allowed us to decrease its effective length, moving its resonance frequency up and deflection down. The result is a unique product which stands head-and-shoulders above its competitors – the best headshell in the world." (www.ipsceramics.com)
Image courtesy of Korfaudio.com
Testing, One, Two, Three...
If nothing else, Alexey Korf is a meticulous researcher and engineer. In 2019, he compared the performance of a slew of different manufacturers' phono cartridges using a unique approach. To isolate the performance of the headshell from a tonearm, Korf deployed a drill press chassis to hold test cartridges with a standard SME/JIS bayonet which, in turn, was gripped tight by a vise. Instead of using a broadband shaker, they employed a very small calibrated hammer; the resulting impulse response, in turn, was analyzed to provide resonant modes and damping estimations data. This was their cost-effective way of testing using broadband excitation, or IET (Impulse Excitation Technique). (Korfaudio.com)
"While for many IET measurements, a microphone is enough, we have decided to use the Endevco Picomin 22 accelerometer as we did before," Korf writes. "It gives a better low-frequency resolution and is known to be linear to its 11kHz resonance frequency. If we discover any significant resonances above that, we might use the microphones, too."
Below is an impulse response from the SME 3009 headshell looks like:
By plotting a spectrogram (spectrum development over time) of the recorded impulse, things become clearer, Korf asserts (see the image below). "There are strong modes at 450 and 600 Hz, and then at 6, 8 and 10 kHz. Damping is relatively poor, with the main modes clearly visible 200 milliseconds after the strike."
Here's that same impulse shown as a waterfall plot, with a 6kHz mode dominating:
Bottom line, with all this research, Alexey Korf came away with a better working knowledge of what works—and doesn't—for the competition, which can be an invaluable tool in running a top flight business. (You can read more about Korf's comparison testing at this link HERE.)
To Infinity and Beyond with Finite Element Analysis
Now, to design their headshells, Korf enlists a technique called Finite Element Analysis. Alexey Korf described it this way via email:
"In our application, Finite Element Analysis (FEA) is a computerized method to predict and visualize how a given object will behave when subjected to forces, vibration, etc. It allows us to iterate the designs without physically building them. It is particularly useful for predicting the design's vibration modes, perhaps better known as 'resonances.' Using FEA, we select shapes and materials that maximize rigidity (stiffness), thus creating a more stable platform for the pickup cartridge to do its job."
The results with their HS-A02 Ceramic Headshell have been well-received. In The Absolute Sound's article, "2024 Recommended Products Under $1000," author Tom Martin wrote, "If you are using a standard removable headshell, this would seem to be the one to beat. We like removable headshells because they make cartridge swapping fairly easy and they save the expense of multiple arms. The Korf has good mechanical rigidity measurements and is reasonably priced." (Theabsolutesound.com)
The Danish website, Pladspillerin.dk compared the HS-A02 with other, more expensive headshells and wrote, "If you are using a standard removable headshell, this would seem to be the one to beat. We like removable headshells because they make cartridge swapping fairly easy and they save the expense of multiple arms. The Korf has good mechanical rigidity measurements and is reasonably priced at $215 or thereabouts."
Moreover, Jam Somasundram also asserted, "I have tested and listened to multiple headshells and I can honestly say that the Korf HS-A02 is the finest device of its kind by a wide margin. You might be surprised that something so seemingly insignificant can change the performance of your tonearm dramatically. The design is based on scientific principles and painstaking research, no snake oil here."
Korf HS-A02 Specs
The Korf HS-A02 fits all the tonearms that accept the standard "SME/Ortofon/JIS" type straight headshells. If you are worried about the headshell mass and its impact on tracking, Korf advises you to use their Tonearm/Cartridge Matching Calculator. Most arm/cartridge combinations work fine with HS-A02.
- SME/Ortofon/JIS type turntable headshell
- Single seamless casting, material: Alumina Ceramic
- Pure silver Litz connecting wires
- Custom gold-plated contact pins
- Custom non-magnetic brass mounting hardware
- Double locating pin for extremely secure connection
- Weight 13 grams, including wires and finger lift
- Light and incredibly strong, arguably as rigid as steel at half the weight
- No internal breaks or lesser materials
- Unique supporting rib minimizes resonances
According to Korfaudio.com, some cartridges need extremely light or highly resonant headshells to sound good and, as such, those cartridges wouldn't benefit from using the HS-A02. Examples include JICO Seto Hori moving coil cartridges and all Grado MI cartridges.
Alexy and Irina Kornienkov (photo courtesy of Ken Micallef/Stereophile)
From Russia to Austria with Love: A Q & A Session with Alexey Korf
So, who exactly is Alexey Korf and Korf Audio? To find out more, I conducted this question-and-answer session via email with Alexey Korf, who co-founded Korf Audio with his wife, Irina Kornienkov.
On engineering, a space program, and his early career:
I was born and grew up in Moscow, then USSR. Got an engineering education. Just started to apply it, working for a Soviet space program, when the USSR fell apart. Escaping the post-Soviet chaos, I found work in the oil industry, living in the UK and later the US (Houston). I came to Austria on a 3-year contract in 2005, but started a family here and stayed for good.
On getting into vinyl, audio, and music:
When I was growing up in the 1970s and 1980s, one didn't "get into vinyl"—vinyl was virtually the only way to enjoy recorded music. Of course, there was radio, cassettes, and reel-to-reel tapes, but the LP was definitely the preferred medium. I started building my own collection as soon as I began making pocket money—at 14 or so if my memory doesn't fail me. I bought a decent turntable as soon as I could afford it—a used Thorens TD-145 with an Audio Technica cartridge.
I am largely omnivorous when it comes to music, but it so happens that about 70% of my collection is classical. We are blessed to enjoy friendships with some truly extraordinary classical musicians. They definitely influenced my tastes. For popular music, the collection stretches from Comedian Harmonists (on pre-war 78 rpm shellacs) to Massive Attack, from The Damned to Ryuichi Sakamoto.
On how Korf Audio came about:
Tried my luck in many different businesses, but always had a dream of doing something with hi-fi. I love music, collecting records, and sharing my love of music was always very important to me. As I don't play any instrument, hi-fi is my way of connecting people to music.
In the late 1990s, my friends and I started a hi-fi repair business. Very quickly we decided to concentrate on turntables, especially the top Japanese ones. They cost pennies back then—Micro Seiki, Yamaha PX-2,3/GT series, Pioneer PL/Exclusive, Sony PS-X, Kenwood/Lo-D, Denon and JVC/Victor "flying saucers" etc. Even had a Teragaki Σ-2000 once (this is when I understood that the whole effective mass/compliance resonance calculation is complete bunk). We had more than 200 repairs documented, of the turntables we deemed very high quality or unusual. This gave us a good understanding of what works and what doesn't. Stopped offering this service once the cost of proper ground-up service for these machines became larger than their market value. Not many people are willing to pay €1000 to get a €400 turntable to "as new" condition.
Initially, my wife Irina and I started Korf Audio in 2011 as a consulting company to share our knowledge of analog with manufacturers, dealers, etc. After a few years, we understood that most of our clients are not really ready for truly interesting ground-breaking solutions. So I thought, ok, we will build them ourselves then.
Our first product was a fully ceramic headshell made as one uninterrupted casting with no joints. Nobody did that before. We launched it in December 2019. It sounds great, the customers love it, and it really put us on the map.
Currently, we build six different tonearm types, the second iteration of our ceramic headshell, and some accessories. We are working on a turntable and hope to introduce it this year.
Alexey Korf at right and Korf Audio employee, Serhii Moroz in front of their window view of the Danube River at Korf Audio headquarters (photo by Alexey Korf)
And now?
Korf Audio is based in the pretty little town of Klosterneuburg, which is a suburb of Vienna. Our office/lab faces the Danube, which makes sunny days so much more enjoyable. Apart from Irina and me, we have one skilled full-time worker building stuff, and a part-time engineer who helps me with research. We outsource some of the metalwork to CNC providers in neighbouring countries, but the final assembly is always done by Korf Audio.
The TechDAS Air Force III (photo courtesy of https://techdas.jp)
On the TechDAS Air Force III, other turntables, components, and loudspeakers in their reference system:
We have a collection of more than 40 turntables that we periodically rotate (sorry for the pun) from storage to the lab bench and back. Currently, TechDAS Air Force III is doing most of the work. Others in the testing duty at the moment are Micro Seiki RX-1500, JVC/Victor QL-10 (TT-101), and the Garrard 401.
I do not know how many pickup cartridges we have in our collection, but it must be more than a hundred. We own (and use) many significant cartridges from the 1950s, 1960s, 70s and 80s.
For amplification in the reference system, reliability and repeatability are super important. Hence, it's all-Accuphase. C-37 phonostage, C-3850 pre, and 2x A-46 power amps. I know that every morning it will switch on, and sound exactly the same as yesterday. No blown or drifting tubes, no temper tantrums. I realize that it is quite possible to get better sounding components cheaper. But they will not provide the same everyday consistency.
For speakers, I am a fan of Greg Timbers's designs. The only one that fits the room that we have is the JBL Array 1400. We also have a pair of 1980s ELACs with omnidirectional ribbon super-tweeters.
That's quite a reference system! However, playing on my Micro Seiki BL-91 turntable with an Audio Creative GrooveMaster 3 Tonearm, Goldring Ethos SE cartridge, Quadratic Audio MC-1 Moving Coil Transformer, Pass Labs XP-17 phono preamplifier, Pass Labs XP-12 preamplifier and Pass Labs X150.8 stereo amplifier connected with Straight Wire premium cabling and their Crescendo 3 speaker cables to a pair of ATC SCM40 loudspeakers in for review, it's sounding pretty good in my listening room, too (you can read more about my system and room by clicking on my byline at the beginning of this review).
Listening Session
But enough talk! The comparison table is set and plated with fine china (the Korf HS-A02 Ceramic Headshell) and silverware (the Audio Creative H-01 Titanium headshell), and now it's time to serve up the aural delicacies!
Listening to Billy Strayhorn's "Take the 'A' Train" with the Korf headshell is a delightfully detailed and tactile experience. From the softer, muted tones of a Yamaha KX25 Midi Keyboard, plucked strings, and resonant body of Yasuo Arakawa's double bass, Takeshi Inomata's brushed snare, to the brassy textures of the saxophone, trumpet, and trombones by Kenji Yoshida, Takeru Siroiso, et al., it's a vivid and vibrant potpourri of big band sound (The Third, Take the "A" Train. Direct Cutting. Toshiba Records– LF-95011. Japan, 1977). You can hear bassist Arakawa's involuntary vocalizations, humming some notes as he plays them!
With the heavier Audio Creative HS-01 Titanium headshell, The Third's rendition of "Take the 'A' Train" remains breathtaking, but it's not quite as detailed in Arakawa's plucked bass strings and resonant body, for example. While rich in the bass, mid-bass, and midrange, it sounds slightly darker, with less articulation in the highs.
Listening to Dire Straits' uptempo "Down to the Waterline" with the Korf HS-A02 headshell is punchy, detailed, and defined, particularly in the mids and treble (Dire Straits. 33 ⅓ Vinyl. Dire Straits. Warner Brother Records, Inc. BSK 3266, 1978). David Knopfler's guitar, sometimes gilded with phase effects, meshes well with Mark Knopfler's, while Pick Withers' shimmering cymbals and crisp drum kit blend well with John Illsley's precision bass and Mark Knopfler's soothing, nasally baritone vocals for a very focused and tight performance.
With the Audio Creative HS-01 headshell (which I also love, by the way) the presentation is lush and a little warmer. In particular, it's a little less bright-sounding in the upper mids and treble regions than with the Korf HS-A02. Sporting a more classical warm vinyl sound, the highs are a little less sparkling with the guitars, snares, and cymbals, for example.
In Eva Cassidy's performance of "It Don't Mean a Thing," the Korf HS-A02 delivers her vocals range and dynamics—one moment scatting, the next belting out lines with sass and swing—with detail and nuance (Eva Cassidy. Nightbird. 33 1/3 LP. Blix Street Records - G8-10210, November 13, 2015). Ditto for the rich piano solo, ride cymbal and punchy drums!
As ever, the Audio Creative HS-01 headshell delivers a splendid and captivating presentation, just a touch heavier and darker sounding with Cassidy's vocals and the band. The contrast between the two calls to mind a time years ago when I sold a Lexicon 212 amplifier (a re-badged Bryston 3B amp) and purchased a used Mark Levinson ML-9 to use in my main system. As with these headshells, I loved them both, with the Lexicon had a wonderfully detailed midrange and highs, presenting a very vivid soundstage, while the ML-9 (which delivered more power and bass to my loudspeakers) sounded slightly darker while delivering a slightly more visceral experience.
This latter point was supported by Alexey Korf, who wrote while fact-checking my review, "The Audio Creative headshell probably sounds richer in the bass simply because it's heavier. For most cartridges, more tonearm effective mass means more bass!"
In Conclusion
The Korf Audio HS-A02 Ceramic Headshell is a superb component to use in the turntablist's arsenal. Enlisting an alumina ceramic unibody construction, at 13 grams, it is extremely stiff, lightweight, and minimally resonant, making it an outstandingly transparent conduit to hear what's going on with your tonearm and cartridge, as well as the music being served up. The resulting aural image is extremely neutral and detailed—especially in the mid to upper registers. It's quickly become a favorite of mine, and one that I can't see doing without. And, as such, I highly recommend it.
HS-A02 Ceramic Headshell
Retail: $210
Korf Audio
