Auditorium 23 to release Step-up Transformer voiced for legendary EMT TSD-15 cartridge

Jonathan Halpern of Tone Imports, and Keith Aschenbrenner, the man behind Auditorium 23 products out of Germany, have confirmed that there will be a soon-to-be released EMT (Elektro-Mess-Technik) TSD-15 Step-up Transformer.

Halpern has had a pre-production version in his hands for more than a month and thinks demand for the new SUT, designed with transformers and windings exclusively voiced for the legendary EMT TSD-15 moving-coil cartridge, will be immediate.

The new EMT SUT will share the same, plain-Jane casework that the current A23 Denon and Ortofon Standard step-up transformers are using.

The new EMT SUT by A23 will feature the same casework as their Denon Standard step-up transformer pictured here.
The new EMT SUT by A23 will feature the same casework as their Denon Standard step-up transformer pictured here.

I had a chance to catch up with Halpern and Aschenbrenner recently via email, and they both graciously consented to answer some questions regarding their introduction to one another (Halpern became the exclusive North American distributor of A23 products after meeting Keith and hearing his products), the use of SUTs in analog front ends with MC cartridges, SUT math and where they stand on hifi and music in general. The following is an edited transcription of our back-and-forth.

SPEC's Yazaki-san and Jonathan Halpern of Tone Imports.
Jonathan Halpern of Tone Imports (right).

From Jonathan Halpern:

RA: A lot of people may not be familiar with Keith Aschenbrenner and his hand-built line of Auditorium 23 audiophile products, which range from horn loudspeakers, turntables, interconnects, speaker cables and of course, his much-lauded step-up transformers or SUTs.

Can you tell me a little about his bespoke line of products, and how did you come to carry them?

JH: Many of Mr. Aschenbrenner’s products have been in production since 1991 or so. I became aware of them back in 2002 while doing some deep, obsessive searching for a certain rare cartridge and Shindo electronics. His website had a mention of a possible upcoming remake of the Neumann DST. I inquired with Keith about this project and of course his experience with Shindo Laboratory products. I believe our first email exchange ended with me saying something to the effect of “one of these days, I hope to have a business just like yours.” I began with Shindo in the Summer of 2003. Keith became a mentor to me, teaching me how to extract the most from Shindo’s products. Everything from set up, to matching, how to really listen, what to expect from one model to the next and eventually the loan of a pair of his amazing hand-made speaker wires. From the moment I placed the cables into my system, I recognized I found the missing link in my Shindo audio chain. Next came his step up transformers, his turntable, his interconnects and turntable mats. Keith always referred to his products as “Shindo’s little helpers.” When he sent one of his step up transformers to Ken Shindo, the reply was simple — the addition of a MM input on all of his preamps for Keith’s transformers. Hearing Keith’s products in a proper chain is really something quite special. His products elevate a full Shindo system from amazing to truly unreal or should I say real.

RA: I learned from you this week that Keith’s latest SUT is designed specifically for the EMT TSD-15 moving-coil cartridge, this cartridge is legend in many circles among audiophiles because of its rich, lush sound, its timbral accuracy, incredible dynamics and natural presentation, how important do you feel this new SUT is in further enhancing the TSD-15’s reputation?

JH: The EMT TSD15 is a cartridge I have been using since around 1998. I found an example during my travels without any documentation or labels. At this time, vinyl was on a real downward spiral and very few people I came across had much info to share. I set up this unknown cartridge in my system, tuned its VTA and VTF by ear and couldn’t believe how much more “analog” things sounded. For years, cartridge companies had been and still seem to be making cartridges that are less and less about music and sound more and more like ice water in the depth of an Alaskan winter. The TSD15 still had a hint of that warm glow while being propulsive, energetic, dynamic and flowing. This new transformer brings out the best in this cartridge. Things tend to sound more natural, more resolute, the timing seems so much more realistic, the silences between notes, the space and inflections become so easy to hear. It’s a real feeling of working less hard to hear the musicians. My initial listening to this transformer was in conjunction with my EMT 927 turntable. A wonderful old broadcast turntable that can sometimes sound a bit too teutonic and mechanical. The transformer somehow removes this mechanical-ness and gives a much more natural flow and pace to music.

RA: One of Keith’s previous SUT designs, the A23 Standard, or A23 Denon, that he researched, designed and builds for the Denon DL-103 – often hailed as “a giant killer” among moving coil cartridges – helped (IMO) re-ignite a passion for this budget cart in no small part because of the tremendous synergy that audiophiles experienced between the 103 and Keith’s SUT.

The 103, like the TSD-15, has been around for over four decades. Why does Keith continue to focus his SUT design energies on cartridges that many would consider dinosaurs with plastic bodies, spherical styli, low compliance and that need to be (ideally) mounted in heavy tonearms?

JH: When one assembles a system based upon quality high-efficiency speakers, one quickly recognizes that these old dinosaurs really have a much more natural balance and correctness than many of the newer concepts. Great sound today is great sound tomorrow, and that was great sound yesterday. This was as true in 1930 as it is today. The marketing driven ideas that MK II, MK III, etc. products are improvements, only says to me they messed up the first time or lost their way. Nothing has happened in cartridge design since the late 1950’s that has been a true “improvement.” As a collector of all types of vintage audio equipment for 20 years, I can say the golden age of audio technology was the late 1920’s until the early 1960’s. Most of it happened on the pro side of the spectrum. The EMT TSD15, Denon 103, Ortofon SPU cartridges all come from the studio/broadcast world. We had talents back then throughout the audio world that stand head and shoulders over what we have today. Many of the designers of these old products would have worked at NASA had they been born 50 years later.

RA: From the few email exchanges I’ve had with Keith, he comes across as a passionate music lover first, and talented engineer and designer second. As a dealer who carries a lot of Keith Aschenbrenner’s gear, how do you think this particular step-up transformer will be received?

JH: One thing I can say when it relates to my dealer network; when I inform my dealers that Auditorium 23 has a new products, the immediate response is often “How soon can I get one?” It’s one of the few products that my dealers have such huge confidence in because of the man behind them. Once people hear this new transformer, I have no doubts it will be a huge success like the A23 103, SPU, Hommage T1 and Hommage T2 transformers before. One of the main differences between Auditorium 23’s transformers and most others is they’re not trying to be a “jack of all trades,” they are specifically voiced and tuned with a particular cartridge in mind. Many transformer “makers” simply buy off the shelf transformers, put them in a box with a switch to change step-up ratios and try to sell them as universal. This does not work nearly as well as the Auditorium 23 approach, in my humble opinion.

RA: Why, in your opinion, does it make the most sense to use an MC cartridge feeding into a step-up transformer connected to a valve-based moving-magnet phono stage for analog playback?

JH: For no other reason than that its by far the most satisfying sounding approach to my ears. Cartridges seem to love step up transformers and step up transformers seem to love MM tube phono stages. From a technical standpoint, this is a great way to minimize noise while adding tremendous gain. Active MC stages generally sound very forced to my ears while step up transformer/tube phono stages just sound so much more like real music to me.

From Keith Aschenbrenner:

RA: Many users of the TSD-15 use your Denon and T1 or T2  SUT with excellent results, what made you want to focus specifically on the EMT TSD-15 for your next transformer design?

KA: The Hommage T1 is designed for my most-loved cartridges, the Ortofon SPU A Classic and Shindo SPU A Classic in the old Bakelite shells. These cartridges are special regarding their coil impedance, amplification requirements  and need careful tuning between the spherical needle along with the characteristics of the transformer.

The Hommage T2 originated in the fact that Ortofon had stopped producing the historical line of SPU A cartridges and in consequence, the limited availability of Shindo cartridges, which are based on the bodies and motors of the original SPU A. Since Jonathan Halpern is the US distributor of EMT, it was an obvious choice to go for a SUT for the TSD cartridge. Thus, the T2 became a pretty good step up for the TSD.

The little transformers for the Denon 103 and Ortofon SPU A (with identical casing but different capsules inside) were always to be seen in context with Shindo’s preamps, good valued assistants for MC-cartridges which were our preferred cartridges for many years: Denon 103, an inexpensive and fair option. Ortofon MC with similar low impedance like the SPU A and also an inexpensive solution for the EMT cartridges from Germany.

Re. development: It grows step by step… one is listening for example, to a Neumann DST or to a Lumière, and the desire comes up to try to add some of their merits to the beloved SPU A by a transformer while trying to preserve the original characteristics, to supplement and to enrich in the best possible way. But there will never be the one and only transformer, because we don’t really know what is in a system as a “whole.” We don’t know how the complete chain with so many unknowns – from equalization, amplification, conversion to the speaker – at the end deals with the “component” listening room… A good transformer reminds me more of a sommelier than of a tapster – pouring or proffering.
RA: Is it true your SUT designs tend to be voiced by ear, or as I’ve heard it referred to recently “the new math,” as opposed to the “old math” of the 10-20x internal impedance of an MC cartridge that many audio enthusiasts like to cling to?

KA: Each manufacturer of transformers has to find his solution between winding mechanism and feeling for tone. “Math” is certainly a good “guide” to make SUTs.

To what extent the components around are helpful remains questionable. It doesn’t help much if “math” is perfect, but sound is not. As for me, I had it rather simple, because I always developed my products along the components of Ken Shindo, I didn’t care much about universal compatibility, and so I stood on solid ground. The fact that my transformers seem to match well with many different cartridges, I have learned from the end users. Priority wasn’t “math” and the study book.
RA: Do think step-up transformers are gaining traction among audiophiles for use with moving-coil cartridges as opposed to active gain stages?
KA: Almost 30 years ago, when A23 distributed the DIY-devices of L’Audiophile in Germany, we built big active transistor MC-amplifiers, battery driven, a huge capacitor supply of 3-Farad filtering, very elaborate, especially for the Denon 103. With the representation of Shindo products in Germany resp. Europe in 1991, we moved back towards the Ortofon TA familiy and got back to the old transformers from our collection like Triad, Partridge, WE, etc. and realized how exciting, and at the same time fluent, forward amplification can be. So, searching and finding holds true even today.
RA: Is the classic, and in many ways timeless sound of the Denon DL-103 and EMT TSD-15 making a comeback against many more modern designs in MC cartridges? And if you think they are, why specifically?

KA: To me it is very charming and satisfying listening to music in a holistic way. Soundstage, looking between, resolution, is not all that counts. I’m not interested in evaluating any coming and going tone to see whether or not I liked it. I believe that the simple needle cuts we see used on the SPU A Classic, Denon 103, the silver EMT-TSD reveal the more beautiful parts in the groove of a record. If the cutting stylus is the benchmark for all things – also for cartridges – why did a company like Neumann build no such thing with their DST 62, a company who knew everything about cutting operations? And what does it tell us that the Denon 103 from 1964 is still being manufactured? But isn’t it great that by the wide range of cartridges every consumer can find his personal preference during his journey through the audio world – there is a wide range and multiple opportunities for any taste.

Many thanks to Jonathan and Keith for taking the time to answer my questions.
–Rafe Arnott

About Rafe Arnott 389 Articles
Editor of InnerFidelity and AudioStream