Robert Deutsch Upgrades His Record Player Soundsmith Zephyr MIMC phono cartridge

Sidebar 1: Soundsmith Zephyr MIMC phono cartridge

The Soundsmith Zephyr MIMC ($1499.95) is a new cartridge that uses much of the technology of the Soundsmith Sussurro ($4799.95), which Michael Fremer raved about in the March 2012 issue. Like all Soundsmith cartridges, the Zephyr MIMC uses what's usually called a moving-iron design, but which Soundsmith designer Peter Ledermann prefers to call fixed-coil. Ledermann makes a persuasive argument about the superiority of fixed-coil over moving-coil cartridges, lower moving mass being the major factor (footnote 1).

Like the Sussurro, the Zephyr MIMC uses Soundsmith's Dynamic Energy Management System (DEMS), designed to neutralize unwanted vibrations. The Zephyr MIMC is a low-output (0.4mV) device intended to be used with high-gain phono preamps, the type normally used with MC cartridges. (MIMC stands for Moving Iron for Moving Coil.) A unique aspect of Soundsmith cartridges compared to other high-end designs is that they can be completely rebuilt for 20% of the original price. Thus, if/when its stylus wears out or its cantilever is damaged, you can have your Zephyr MIMC rebuilt to as-new condition for $300. In these days of electronic appliances that cost more to fix than to buy new, Soundsmith's policy is most welcome.

The load recommended for the Zephyr MIMC is 470 ohms or greater. My Convergent Audio Technology SL-1 Renaissance Black Path Edition preamplifier has a transformer-based MC section with an output impedance of 4k ohms, but this value can be changed with paralleled plug-in resistors. I discussed the load issue with CAT's Ken Stevens, who suggested that I try the Zephyr first with no plug-in resistors, an arrangement that he said worked well with most MC cartridges, though he admitted to having had no experience with low-output MI/FC cartridges such as the Zephyr MIMC. He sent me a collection of plug-in resistors and suggested that I try all of them. Using the formula he provided for calculating the total parallel resistance (R1 x R2/(R1 + R2), with R1 being 4000 and R2 whatever is plugged in), I compared the sound with: 1) no plug-in resistors (ie, 4k ohms); 2) plug-in resistors of 500 ohms (total 444 ohms, just under the recommended minimum of 470); 3) 1k ohm (total 800 ohms); and 4) 2k ohms (total 1333 ohms). My favorite was 1333 ohms, which produced the most neutral tonal balance; in second place was no plug-in resistors, or 4k ohms; and 444 ohms sounded rather thin.—Robert Deutsch

Footnote 1: Click here for more information.

Boogieman1's picture

Dear Sir,
I enjoy your writing very much - all of your pieces are very well written. However, a big question remains after reading this article: how did you go about selecting the turntable? There are so many brands out there - vpi, clearaudio, rega, avid, sme, spiral groove, oracle, basis, kuzma.....

Add combinations of tonearms and cartridges, and one can go completely crazy just thinking about all the possibilities, let alone listening to all the combinations.

So how do you recommend one select a turntable?
Thank you

Robert Deutsch's picture

Thank you for the comment on my writing.
You're right: selecting a turntable is not an easy task. There are lots of 'tables out there, and there is hardly ever an opportunity to compare the sound of different turntables in stores with everything else in the system kept as a constant. In the absence of personal experience, turntable selection is a bit of a guessing game, albeit an educated one. Prior to my experience with Acoustic Signature, I have not reviewed any turntables myself, so, in selecting a new turntable, I had to rely largely on the opinion of others, including reviews in Stereophile (and, yes, even other magazines/webzines). It was actually Herb Reichert's writeup of the WOW XL that first piqued my interest, and, talking to some people in the industry, including Peter Ledermann of Soundsmith, helped me to zero in on Acoustic Signature as offering high quality and high value. And, I figured, if the XL is good, the XXL is likely to be better. There were some other turntables that I was considering, and I can't say whether the one I chose was the best, but it's certainly an excellent turntable, especially with the various tweaks I described.
As for a general recommendation on how to select a turntable--well, I don't think there's a formula that will guarantee you'll choose the right one. An obvious first step is to make a tentative decision on how much money you're willing to spend--keeping in mind that if you're also buying a tonearm and a cartridge, there may be tradeoffs in allocating parts of your budget to various components. By all means read reviews--but don't expect them to make the decision for you. Go to local audio stores, and talk to them about turntable recommendations. (Just don't expect them to be completely impartial in any negative comments about products they don't carry.) Go to regional audio shows, where you're likely to see products you may not be familiar with, but which should be considered. Try to get a demo.
And once you have your new turntable setup, stop reading about other turntables and just listen to the music!

billdevaux's picture

Dear Robert,
I am very interested in your opinion of the Soundsmith cartridge but what really got my attention was your mention of using plugin resistors in some of your listening tests with it. I'd like to know if you felt they degraded the sound in any way? I'm curious because I'm thinking about using plugin capacitance adjusters (from DBSystems) to match capacitance on MM cartridges. Many good MM phono stages lack the ability to match preamp and cartridge capacitances.


Bill Devaux

Robert Deutsch's picture

The plug-in resistors did not degrade the sound in any way (except for the one that represented a mismatch). However, this conclusion should not be generalized to the use of other plug-in resistors/capacitors with other phono stages/cartridges. The CAT preamp has paralleled phono inputs, so there is no external device involved.
But, now that I think of it, years ago I had a preamp that had no built in provision for plug-in resistors/capacitors, and I remember using RCA Y-connectors for capacitors. I never checked whether the Y-connector itself caused any sonic degradation, but the appropriate capacitive loading improved the sound.

helomech's picture


I enjoyed reading your article. I recently purchased a Wow XL and awaiting its arrival.

I also ordered the Acoustic Signature tonearm and opted for the DIN connector.

Can you tell me if the Cove cable that came with your tonearm has a 90 degree or straight connector at the table end? The Zavfino site displays both types. I would imagine the straight connector might have clearance issues on the Wow. This information would be of great help because I'd like to make my own 1/2 meter cable before my Wow arrives.

Many thanks.