Antiphon Audio Labs MC Drive
Passively powering up a moving coil cartridge.
Review By Steven R. Rochlin
Click here to e-mail reviewer.

  Over the years i have tried a staggering amount of cartridges, turntables, tonearms, and phonostages. As a result, when the good folks at Antiphon Audio Labs asked if there was any interest in reviewing their MC Drive i was all ears (pun intended). Like every good audiophile seeking the next plateau, my hopes were to increase the resolution and musical bliss from the grooves within the 7,000+ records in my humble abode. While the politics and major electronic companies continue their nearly never-ending sword fight concerning the digital disc format wars, many music lovers seek what in considered by many to be higher ground. SACD and DVD-Audio combined do not add up to a small handful of releases as compared to CD, let alone vinyl. With "perfect sound forever" being the early mantra of Sony's and Philips' CD format decades ago, and "The look and sound of perfect" being HD-DVD call tag, why is there zero consensus about any format being perfect? And no matter what any of the major manufacturers say, audiophiles enjoy their vinyl hardware and software as new products and music titles fill the desires of a clamoring faithful.

To that end, four turntables, a myriad of cartridges, and more phonostages than one man should be allowed to own occupy my home. My recent fave you can purchase today and enjoy hundreds of thousands of music titles (take that SACD and DVD-Audio!) include the Oracle Delphi MK. V turntable (reviewed here), Clearaudio Stradivari MC cartridge (reviewed here), and Ray Samuels Audio Emmeline XR-10B MM/MC phonostage (reviewed here). For this review the only change to the above setup is the use of Antiphon Audio Labs' MC Drive and Lehmann Audio's Black Cube with uprated power supply in exchange for the Emmeline unit (review forthcoming). And with all that said, it is time to investigate the advantages of passive step-up transformers.

Stepping-Up To The Plate
Audiophiles have various ways to change the volume, impedance match, and increase the output of various devices. These options are generally in using active or passive devices. A web glossary defines an active device as "Devices such as transistors, integrated circuits and vacuum tubes that require an external power source in order to perform an intended purpose, such as amplification." Meanwhile a passive device uses virtually none of the above and is, usually, transformer-based. Transformers are found in virtually all electronics for use in power supplies, tube output stages (except OTL of course), and for interstage use.

For many decades transformers have played a key role in delivering power to homes worldwide. My guess is that there is perhaps 5 transformers for every man, woman, and child in the world today. So as you can see, this form of technology is understood and in wide use globally. But what does this have to do with moving coil cartridges and what are the benefits?

Without active components, a step-up transformer does not suffer from electricity delivery and power supply related problems. Another benefit is step-up transformer devices can be specifically 'wound,' the coupled windings within a magnetic core, for the specific task at hand. Generally, and in the case of Antiphon Audio Labs' MC Drive, more wire windings produce additional gain. Like virtually all things audio, the quality of the transformer's wire, the materials (laminate, etc.), plus the overall design and quality can spell the difference between a great product and one that could be considered mid- or low-fi. The reason to use a passive step-up transformer for moving coil (MC) cartridges is that it raises the output to moving coil (MC) territory, thereby we need less active amplification in the gain stage.

Antiphon Audio Labs feels that (their words, not mine):

1. Narrow band of frequency response.
The conventional step-up transformers for moving coil cartridges have rarely provided the acceptably flat frequency response for Hi-Fi music reproduction purpose. In terms of technical specification, most transformers insist to have frequency response of 20Hz to 20kHz. However, in reality they usually emphasize only the middle frequency range while they show declining frequency response at extreme frequency spectrums. For instance, conventional transformers do not provide flat response for frequency below 100Hz or above 10kHz. When music signal of these extreme frequency ranges is fed, with the conventional transformers the music signal is amplified at a far lower level than that of the middle frequency range (say, above 100Hz and below 10kHz). Accordingly, to human ears, the reproduced music seems to lack low frequency impact and weight and high frequency extension and openness.

2. Deficient ability to preserve musical information.
The most conventional transformers usually offer the sufficient and robust amplification of the fed music signal. However, such amplification is provided only at a macro level. In other words, although the fed music signal is boosted at an acceptably loud level, all the musical details and inner resolution are gone and lost. This leads to the loss of musical nuance, taste, impression, spatial sense, soundstage layers, and, most of all, the rejection of the virtual-experience of original venues.

3. Limited life span for its optimum performance.
Due to inappropriateness and deficiency in transformer winding skills, the conventional transformers usually begin to deteriorate its performance after 2 to 3 years. The reason is that the intervals and the tension of wound coil are constantly changed and deformed through the course of usage. The life of a transformer is the repetition process of physical expansion and contraction. When an electric signal is fed to a transformer, the transformer generates heat and its temperature rises, expanding its physical size. When the transformer is not in use, its temperature returns to a lower degree and, therefore, it physically contracts. After repetition of these expansion and contraction process, the internal structure of a transformer becomes loose and the interval and the tension of wound coils are changed, leading to a deteriorated performance of the transformer. This is why conventional transformer-based audio equipments show a lowered level of performance after 3 to 5 years of use.

More Technicalities
So with that said, we now see why Antiphon Audio Labs feels their design is noteworthy, and why curiosity led me to reviewing their unit. They were kind enough to send me their lowest gain model with 14 times gain that has an input impedance of 100 Ohms. The output impedance of 10,000 Ohms, which is said to be good for cartridges with 0.5mV or higher output. Antiphon Audio Labs does note "Due to the very low DCR of the secondary winding coil, the MC Drive does not necessitate separate impedance matching for the connection to the 47,000 Ohm input of a RIAA equalization circuit."

This is not my first time with such units, as my very low output Audio Note Io-2 cartridge enjoyed its marriage with the truly excellent and first-class Audio Note AN-S6c silver wired step-up transformer. While the Audio Note did offer various selections/winding for load plus impedance, and cost around twice that of the Antiphon Audio Labs' MC Drive, the unit under review is a simply plug and play with no adjustments. The rear panel has right and left RCA inputs and a centrally located ground terminal. The RCA jacks are of very high quality and all rear terminals are gold plated.

Antiphon Audio Labs claims a wide and flat frequency response from 10Hz to 40Hz (±1dB), which is quite good considering the virtually flat response. Of course the specification would go higher up in frequency if they played the ±3dB game. Over ten years of research and development have allowed for a very mature design with their proprietary transformer technologies. Specifically, the mixture of coil winding direction and location, where Antiphon Audio Labs uses twice as thick a coil in comparison to other transformers.

Once the transformer is made, it is vacuum-pressurized and placed within a vacuum tank filled with Antiphon Audio Labs' proprietary impregnating solution fluid. During this vacuum pressurization process, the proprietary impregnating solution fluid fills every space inside the transformer structure, no matter how tiny the space is, without exception. After impregnating, the transformers are naturally dried for 24 hours. Oh, and then the unit goes through multiple baking processes at varying temperatures for 24 hours. And so says the company, "In order to pick up a precisely matching pair of transformers, five transformers are accurately measured and tested to satisfy the requirement of 0.1 percent tolerance."

The chassis is designed to avoid vibration and milled from an aircraft-grade duralumin block. Inside the milled duralumin, one chamber is provided to accommodate a pair of steel cylinders that are also entirely milled from a steel block. These steel cylinders encase each step-up transformer. The thickness of the steel cylinder is a minimum of 7mm to avoid any magnetic interference, while the duralumin case has a minimum of 10mm thick wall. Finally, three pointed cones support the chassis to drain any air-bone vibrations. This chassis is gorgeously wrapped in ten-year matured African Bubinga wood. The assembled case is treated by multiple steam-pressurization and drying process to keep its rigidity and shape. It is then stained and hand polished to expose the natural beauty of Bubinga wood grain.

Finally, My Listening Notes
Antiphon Audio Labs felt their low, 14 times amplification ratio step-up unit would work best for the Clearaudio Stradivari. This was a simple plug-n-play affair and then just had to sit back and wait for things to settle in. Right out of the box the unit sounded very impressive! Fortunately, as time passed there was no major changes, just a nice small evolution to more of...

Those of you who read my Oracle Delphi MK. V review (seen here) know how much joy it brought into my humble abode. The only real quibble was the lack of lowermost frequency extension. One of the first things in my notes is how well the deepest bass notes were brought back into the fold of the upper frequencies. This is not to say a bass boost, but more of bringing things back into how they should be. Perhaps my ears have been so attuned by the nearly decade-long tweaking of the Voyd Reference turntable that anything to come close to its performance has a formidable task at hand. 

Moving upward on the frequency scale, midbass was tight and tuneful with perhaps a touch more PRAT (pace, rhythm and timing). Some of this could be attributed to the deeper bass. As this is all part of the lower frequency range, one would expect a natural interaction as the frequency range and harmonics come into play. From acoustic jazz to electronica, my ears felt there were only gains and nothing lost by using the MC Drive compared to sans the MC Drive.

Moving to the midrange, it was hard to detect much of a difference, which is a good thing! All the midrange bloom and high resolution as written within my Oracle review (i.e. the difference between room acoustics and that ol' studio reverb sound) was all there to be heard. Harmonics were neither rosy-colored nor etched. They were simply brought forth in a natural, relaxed yet highly defined way. This is something high-end vinyl replay gets so right, whereas digital easily gets so wrong. This is not to say digital midrange is bad mind you, far from it! It is to say that the ease with which vinyl gets midrange right as compared to its digital counterpart.

As for the uppermost frequencies, above 1kHz, extension was excellent as cymbals shimmered and concert bells/chimes on classical recordings shined. Speaking of CD, only the vinyl of Pink Floyd's album Division Bell [Columbia C64200] is the format to choose (note: the CD version is horrendous). The beginning of the first track "Cluster One" has very high frequencies amidst the 'noise,' then the piano comes into play as do other instruments. Over the years i have found that, sadly, very few systems can reproduce this vinyl album without leading towards edginess and/or miss the very subtle graceful microdynamics within the grooves.

As i type this and once again listening to Division Bell, there is a gentle flow and decay with what i'd consider a medium reverb set at slow decay on the guitar. Very well balanced, as then the deep bass kicks in for the song "What Do You Want From Me." Guess what i am trying to say is the MC Drive provided...

"You can lose yourself this night
 See inside there is nothing to hide
 Turn and face the light"

Front soundscape was perhaps a touch deeper while surrounding and enveloping of the soundscape had a more relaxed, naturally gentle feel. This could be due to the ability of the MC Drive to handle the very small electronic signal changes and send these to the phonostage, which now has to provide less active amplification. Imaging remained excellent, very precise and well-defined.

Harmonically, the MC Drive provided a more even and preserved top to bottom rendition than i felt was possible with this setup (quite frankly). Perhaps there is something about top quality MC step-up transformers that should, no, make that need to be investigated by vinyl lovers with MC cartridges? Perhaps this transformer magic is also why many audiophiles are now clamoring for transformer-based volume controls such as the Promitheus TVC passive preamplifier (review forthcoming) and Audio Consulting's Silver Rock Transformer Potentiometer (reviewed here). The plot thickens!

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Sum Of The Parts
While basic transformer design is not new technology, nor the latest in the never-ending commercialized and debated high-end digital format wars, you can rest assured that Antiphon Audio Labs' MC Drive will never need new firmware, never need to be reset, will never suffer from a power loss, and will perform day in and day out without a complaint. There is little doubt that transformer-based passive preamplifiers, tube amplifier transformers, and MC step-up transformers have their place within many high-end music reproduction systems.

To that end, the music now emanating from the Oracle/SME/Clearaudio/Antiphon/Lehmann combination was a resounding success! After months with the Antiphon Audio Labs' MC Drive all i heard are improvements from top to bottom and all aspects concerning soundstage and imaging. Maybe this is a magic combination where the sum of the parts is extremely synergistic? No matter what the cause, the affect is one road i am glad to have had the opportunity to travel. Needless to say, the MC drive will be leaving my home when you rip it from my cold, dead hands!

Antiphon Audio Labs' has informed me they are sending their 28 times gain unit so it can be compared to their 14 times unit. Very much look forward to receiving it and, perhaps, reporting on the differences if i feel it necessary. In conclusion, i wholeheartedly recommend all MC cartridge users to seek out top-quality transformer-based step-up devices.

Enjoy the Music (Pink Floyd "Keep talking" right now),

Steven R. Rochlin

"For millions of years mankind lived just like animals.
 Then something happened which unleashed the power of our imagination.
 We learned to talk" — Stephen Hawking

Specifications
Type: Passive transformer-based moving coil step-up unit 

* Due to the very low DCR of the secondary winding coil, the MC Drive does not necessitate separate impedance matching for the connection to the 47,000 Ohm input of a RIAA equalization circuit.

Frequency Response: 10Hz to 40kHz (±1dB)

DCR of the primary winding coil: 5 Ohms

DCR of the secondary winding coil: 140 Ohms

Inductance of the secondary winding coil: 80 Henries

Weight: 19 lbs.

Dimension: 6.5 x 8.25 x 4.5 (WxDxH in inches)

Warrantee: 20 years (transferable)

Price: $ 3,900

Company Information
Antiphon Audio Labs
Sinsung Officetel A-604
1857 Seocho 3-dong
Seocho-gu Seoul
South Korea

Voice /  Fax: +82-2-525-6550
E-mail: marketing@antiphonaudio.com
Website: www.antiphonaudio.com