However after I write this month-to-month column, I discover myself aiming for a unique really feel, extra like driving cross-country in a ’70s Ford station wagon, documenting motels and fuel stations. A visit the place it is enjoyable to roll straightforward, take within the views, and cease at each automobile museum, snake farm, and stalactite cave.
This month, I’ll put some miles on the Ford’s odometer as I examine the results of Ron Sutherland’s latest current-drive creation: a $3800 transimpedance shifting coil headamp known as the SUTZ. Alongside the best way, I will even re-review Dynavector’s $1250 DV-20X2 shifting coil cartridge and study what is likely to be the sweetest spot in Dynavector’s cartridge lineup: the $2150 XX-2 MKII.
Lastly, I will pull right into a relaxation cease, get out of the automobile, and refamiliarize myself with Lounge Audio’s $355 Copla headamp, a product I’ve used with enthusiasm since I reviewed it in February 2018 however haven’t written about since that first evaluate.
Sutherland Engineering SUTZ
I’ve spent loads of time attempting to image all of the electromagnetic hoopla brought on by wiggling a stick related to some wire coils in a magnetic discipline. I’ve pictured the bumpy report grooves shaking a tiny stylus/cantilever/coil meeting, stretching its tensioning wire whereas swinging its coils by means of the mounted strains of magnetic flux created by a really small equal of a horseshoe magnet. Because the coils transfer by means of the magnet’s flux, an electrical present is induced alongside their size.
I discovered to image this Faraday’s regulation half in grade college. In highschool, a instructor defined Lenz’s regulation, and that was trickier to understand: “The polarity of the voltage generated by adjustments in magnetic flux produces a present whose magnetic discipline opposes the change which produced it.”
Surprisingly, as I labored to think about how current-drive audio levels work and why they have an effect on the sound of cartridges the best way they do, I remembered Lenz’s regulation and its magnetic pushback. That reminiscence prompted me to take a position that loading a shifting coil cartridge with a digital quick (no voltage on the enter) would maximize present stream by means of the cartridge coils, which in flip would max out the power of the Lenz’s regulation pushback, instituting the best potential damping on cantilever-coil motions (footnote 1).
Subsequent, I attempted to think about how this current-induced damping may examine to the damping instituted by a standard shunt resistor previous an lively stage. I’ve at all times presumed that each one variations in loading/damping have an effect on how reliably the stylus traces the report’s grooves, and I had already concluded that variations in damping (nonetheless they come up) are answerable for variations in monitoring, groove noise, the sense of internal element, and intermodulation distortion.
After which my Herb-brain questioned: what about step-up transformers?
Up to now, I’ve reviewed a bushel of shunt-load phono levels, quite a lot of step-up transformers, and three “transimpedance” phono levels: Lounge Audio’s $355 Copla, Dynavector’s $895 P75 MK3 phono preamplifier, and Sutherland Engineering’s $3800 Little Loco.
Traditionally, my style in phonographic copy has favored high-nickel step-up transformers trying to vanish in entrance of the atmospherics and incandescence of tubed RIAA equalizers. Currently, although, I have been bathing within the excessive densities of low-signal info being recovered by Sutherland Engineering’s Little Loco current-drive phono preamplifier, which I have been utilizing with the My Sonic Lab low-output (0.3mV), low-impedance (0.6 ohm) Extremely Eminent EX shifting coil cartridge. The Little Loco appears to enlarge each little factor this cartridge offers it. In comparison with how the Eminent EX sounds into Parasound’s Halo JC 3+ phono stage, the My Sonic–Loco combo performed greater (picture and soundspace-wise) and extra elegantly (texture and proportion-wise)—with an abyss-deep silence sitting behind the notes.
So abruptly I’ve this dilemma: How do I get all that short-circuit silence and grainless microdata and never be compelled to surrender the CinemaScope and Technicolor of tubed RIAA levels?
I defined this dilemma to my “turntable-whisperer” pal Chad Stelly, and he defined it to our mutual pal Ron Sutherland of Sutherland Engineering (footnote 2); Ron responded instantly: “I’ve already solved that!” Every week later, I am connecting Ron’s latest invention, the “SUTZ” transimpedance headamplifier, to the 47k ohm shifting magnet enter of my all-tube Tavish Design Adagio phono stage.
Sutherland Engineering’s SUTZ headamp arrived in the identical 17″ × 2″ × 13″ chassis because the Little Loco preamp I described within the January 2022 Stereophile. Actually, the SUTZ seems precisely the identical, inside and outside, because the Little Loco. Inside, it sports activities the identical three jumper-activated Acquire settings because the Little Loco. Once I requested how a lot acquire the SUTZ makes, Ron informed me in an e mail that each one future SUTZ can have 5 acquire settings; however solely after scolding me, explaining that “transimpedance amps wouldn’t have ‘acquire’ as a result of the models in (amperes) are totally different than the models out (volts).” (footnote 3)
Earlier than I start my listening tales, I ought to point out that the element grouping I used was what I name my all-tube “real-fi” system: cartridge and step-up transformer du jour, connected to a ten.5″ Thomas Schick tonearm connected to Dr. Feickert’s Blackbird report spinner, feeding Tavish Design’s Adagio phono stage or SunValley’s SV EQ1616D phono equalizer, feeding Lab 12’s Pre 1 line-level preamplifier, into Elekit’s TU-8600S SE amplifier (with Western Electrical 300B tubes) powering Falcon Gold Badge audio system. Throughout these auditions, I used to be always reminded how a lot I get pleasure from this method and the way it performs recordings with larger verity of tone and lifelikeness than any system I’ve assembled since I began writing for Stereophile.
Dynavector DV-20X2
Since I reviewed it in Gramophone Goals #10, no cartridge has performed extra discs in my room than Dynavector’s $1250 DV-20X2 shifting coil. I’ve put a whole lot of hours on it, enjoying it by means of at the least a dozen phono levels. It performs the best way I like phono cartridges to play: clear, quick, and insightfully. It is acquired sufficient mojo-vivo to make high-energy recordings with sword-sharp transients sound gunshot explosive and completely relaxed on the similar time. Few cartridges at this worth degree can do each. Many cannot do both.
Even with all these hours on it, the 20X2 had no problem doing this explosive-but-relaxed factor whereas cleanly reproducing considered one of field-recordist David Lewiston’s most interesting and hottest recordings: “Ketjak: the Ramayana Monkey Chant” from the Nonesuch Explorer Collection LP Golden Rain (Nonesuch Explorer LP H72028). The highly effective percussive transients generated by 200 monks chanting in unison got here by means of as startling, even after I knew their shouted “tjak” outbursts have been coming. The concentric association of the monks within the courtyard was simply discernable. Throughout quiet passages, my thoughts’s eye loved pinpointing the placement of particular person monks chanting on the far sides of those circles. When the monks paused their shouting, the ambient sounds of the courtyard allowed me to see and really feel their presence. Cartridges with this diploma of insightfulness are uncommon at this worth degree.
Each time I performed “Monkey Chant” with the Dynavector’s 20X2 MC into the Sutherland SUTZ and the all-tube SunValley SV EQ1616D phono equalizer, I used to be awed and dizzified by the uncooked readability, breakneck pace, and free-swinging dynamics of the presentation; these “tjak” transients got here by means of sharply and powerfully with noticeable areas between chanters’ voices. For me, this was a brand new kind of Wow! second: current-drive info aesthetically enhanced by the SunValley’s tubes.
Dynavector XX-2 MKII
Chad Stelly raved to me in texts concerning the “unbelievable synergy” of Dynavector’s XX-2 MKII shifting coil with the Sutherland SUTZ, so I contacted Mike Pranka at Toffco, Dynavector’s US distributor (footnote 4), and he corroborated Chad’s statement: At $2150, the XX-2 MKII might be the “candy spot” in Dynavector’s cartridge lineup. It is the purpose the place the largest portion of Dynavector pleasure kicks in.
My ongoing attraction to Dynavector cartridges is fueled by their claims that they focus their engineering packages on the coronary heart of the matter: magnetic circuit design. Their web site explains, “By our calculation and experiments, it was proved that even a really small deviation of flux makes a change of magnetic power within the air hole, which impacts intermodulated distortion within the output sign.” That’s the reason Dynavector favors Alnico 5 magnets over samarium cobalt or neodymium boron. The said function of Dynavector’s patented “flux damping” and “softened magnetism” is to reduce “unfavored magnetic fluctuation.”
The XX-2 MKII makes use of Alnico 5 magnets (footnote 5) as a result of they exhibit excessive magnetic flux density, which “generates a extra secure flux-field which maintains a extra secure output voltage” than different magnet varieties, in response to the Dynavector web site.
The XX-2 MKII sports activities a low (6 ohm) inner resistance and a low, 0.28mV output voltage. Its motor is housed in a inflexible 7075 aluminum physique, and the cartridge weighs 9.2gm. Compliance is specified at 10µm/mN, and Dynavector recommends a low (30 ohm) load.
The 20X2 makes use of a nude MicroRidge stylus on a tough aluminum-pipe cantilever, whereas the XX-2 is the lowest-priced cartridge within the Dynavector lineup that makes use of a stable boron cantilever, tipped with a 7 × 30µm Pathfinder line-contact stylus—which, if I bear in mind appropriately, is identical Ogura diamond utilized by Lyra and Koetsu.
Footnote 1: Herb has it precisely proper right here. For the mathematically inclined: Low resistance means increased present, which implies a bigger magnetic power on the present loops. That power is proportional to the shifting coils’ velocity—the primary spinoff of the place—which is the damping time period within the differential equation describing any resonant spring system. Extra power at a given velocity makes the coefficient of velocity bigger, which implies extra damping.—Jim Austin
Footnote 2: Sutherland Engineering. Tel: (816) 718-7898. Net: sutherlandengineering.com
Footnote 3: Technically, there is not any problem defining acquire for a transimpedance phono preamp: It is the identical as at all times, the ratio of voltage out to voltage in or present out to present in—decide one. However that’s not the amount of curiosity for a current-input phono stage, the job of which is to remodel present into voltage. For such a tool, the analogy to a step-up transformer is irresistible; that is in all probability answerable for Ron Sutherland’s resolution to name this product the SUTZ: You’ll be able to consider it as a brand new form of step-up transformer even when it is not a transformer within the typical sense. Why the Z on the top? In all probability as a result of the pure strategy to characterize a transimpedance gadget is through the ratio of the output voltage to the enter present, which has models of impedance, and impedance is often indicated by the letter Z.—Jim Austin
Footnote 4: Dynavector Techniques Ltd., 3-2-7 Higashi-Kanda Chiyoda-ku Tokyo 101-0031 Japan. Tel: +81 (0) 3-3861-4341. Net: dynavector.com. US distributor: Toffco, 2020 Washington Ave., Unit 314, St. Louis, MO 63103. Tel: (314) 454-9966. Net: dynavector-usa.com
Footnote 5: The quantity after “Alnico” signifies the actual alloy of aluminum, nickel, cobalt, copper, and iron. Alnico 5 is particularly wealthy in cobalt and barely extra magnetic than different Alnico alloys. For what it is value, electrical guitars with pickups primarily based on Alnico 5 are mentioned to have sharper transients and brighter tone.—Jim Austin
