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From: chowkwan@alumni.cco.caltech.edu (Raymond Maihin Chowkwanyun)
Date: Thu, 17 Feb 1994 21:03:04 -0800
Subject: The Empire Strikes Back

The Empire Scientific that is.  Owner, Ernst Benz, co-inventor with 
Dr. A. J. van Den Hul of the moving coil cartridge, is not going down
to the forces of CD without a fight.  Together with his partner,
Albert Lukaschek, Herr Benz manufactures a complete range of cartridges from
the entry-level Silver and Gold models to the state of the art,
MC Reference and Ruby.  Still, it's a far cry from the glory days
when they turned out 9,000,000 styli a year.  That's 17 styli a minute
and the machines ran day and night.

I had the distinct pleasure of visiting the Empire's headquarters in
Neuhausen Am Rheinfall, site of the (surprise!) spectacular Rheinfall.
It's not that high but it has a certain dash and vim about it.  The factory 
is what you'd expect a Swiss factory to be.  Incredibly neat and tidy.
And Herr Benz kept telling me what a mess the place was on account of
they were re-arranging the shop floor.

When is a moving coil cartridge not a moving coil?  When it has iron
in the magnetic field.  This means all micro Benz cartridges are not
true moving coils, saving only the top of the line Ruby where the coils 
are wrapped around a (second surprise!) ruby.  The only other ruby cartridge 
I'd come across was the old Grace F9E Ruby whose cantilever was made of ruby.  
I'd breezily made the assumption that the Benz Ruby was an MC Reference
with a ruby cantilever.  Wrong!  They, in fact, share the same boron
cantilever.  It's the coil assembly that's completely different.
Even to the naked eye, it's apparent that the MC Reference's coils are
wrapped around a small metal cross.  The Ruby's coil arrangement is
considerably denser and more complicated.

It takes a technician 15 minutes to create the MC Reference's coil
assembly, the whole time looking through a microscope (Olympus).
Gold wire, thinner than a human hair, has to be painstakingly 
wrapped with the aid of a machine tool custom designed and built by Benz.
And you have to keep track of which wire is the right channel, 
the left channel, positive, negative.  The Ruby's coil assembly takes 
30 minutes to create. As you can imagine, the attrition rate amongst 
trainees is pretty terrific.  Herr Benz told me it takes about two 
months to train a technician in the art of coil winding.

Because these cartridges are hand-wound, there are inevitably
differences of sound between individual units (within tolerances).
Herr Benz assured me these differences are small for which I will
take him at his word, not being ready to invest in a bunch of
Rubies and References to engage in an experiment.  Besides, I 
kind of like the idea that no two cartridges are exactly alike.
It makes me feel they were created by a human being instead of
being churned out en masse.

Under the microscope, these moving coil cartridges are revealed to be the 
beautiful works of art that they are.  This is one lean, mean, music-making
machine.  I found them endlessly fascinating to look at - the incredible
detail of the coil windings, the tiny but burnished metal parts all
bespeaking a loving hand craftsmanship but there were other things to see
like the complete machine tool shop where they make all the iron yokes 
from scratch, beginning with little chips of raw iron.

A wooden body protects this delicate engine.  Benz uses Bruyere (accent
grave over the e) wood which is used to make pipes No two surfaces
in the body are parallel in order to reduce resonances and there is no
bottom.  i.e. the cartridge is semi-open.  I asked if the practice of
running nude cartridges had influenced this design to which Herr Benz
forthrightly replied in the affirmative.  And the wooden body idea
came from Koetsu of which I saw a couple of examples in for repair.
Koetsu owners take note.

How did the Empire get its name?  It is, in fact, the old American
Empire company.  They still have an Empire turntable of early 70's
vintage.  I had completely forgotten about Empire but seeing that
turntable flashed me back 20 years to when I started out in audiophilia.  
Of course, the old turntable is of historical interest only.  Nowadays they 
use Micro-Seiki and Revox turntables which are only 10 years old in design
and themselves collector's items.  The Micro-Seiki is a direct drive design
which can accomodate 3 pivoting arms at the same time.  A god-send
for the cartridge manufacturer wanting to test out arm compatibility.

Herr Benz quizzed me about the Graham 1.5t arm which I had no hesitation
in recommending to him as a replacement for the SME V.  Such a change would
net him more accurate bass performance at the least.  Surely the
Graham is the top pivoting arm in the world today.  I'll just as
surely hear from a lot of angry Wheaton owners for that last remark.

The Revox is a linear tracking turntable which Benz modifies by
damping the platter with bitumen, replacing the plastic headshell with
a tooled metal shell, and eliminating the automatic damping circuits.

They also have a special linear tracking turntable for measurement
purposes only.  The arm can only be moved by human intervention,
i.e. it doesn't follow the groove.  They plonk the cartridge down
onto different sections of a test record and the results are automatically
measured on a Bruel (umlaut over the u) and Kjaer paper recorder.  Each Ruby 
and MC Reference is tested out on this rig as a final quality control and
the resulting graph showing frequency response and crosstalk is supplied with 
the cartridge.  

We pored over a couple of graphs for the MC Reference and Ruby.
The first thing you notice is that the frequency response is ruler flat.
Moving coils have a reputation for a rising top end but it just
ain't so.  Herr Benz explained that judicious selection of
materials and careful arrangement of the geometry of the internal
engine were responsible for the flat response.  I have encouraged
him to write a treatise expounding in general terms about cartridge
design so I will leave it to him to go into greater details.

I did ask how did he know what to change if a design turned out to be 
unsatisfactory. Basically, he uses the standard scientific approach of 
changing one variable at a time to see the effect it has.  There are some 
preliminary calculations that can be made beforehand but they are, at best, 
a rough estimate.  To really find an optimum arrangement takes lots of 
tedious trial and error.

When looking at a chart of frequency response and crosstalk, what
is measured is the frequency response of *one* channel vs the crosstalk,
or interfering signal, from the other channel.  The lower the crosstalk, 
the better the separation in signals between the left and right channels.  
While the frequency response curve may be flat, the crosstalk curve tends 
to rise with frequency.  At times, this curve can be quite choppy.

At 1Khz, the crosstalk was around -40 db for both the MC Reference
and Ruby.  Beyond that point the crosstalk curves had very different
shapes.  I would say the Ruby curve was choppier but on average,
showed better separation by about 5 db.  You understand, I'm eyeballing
the chart, it's not precise but it's correct to first order.  
>From 1 to 5Khz the crosstalk rose rapidly for the Reference and hits 
a plateau.  The Ruby has a peak at 3Khz but generally is has less
crosstalk.  The same pattern is repeated for the 3Khz to 10Khz range
and for the range from 10Khz to 20Khz by which point the crosstalk
is about -30 db.

I asked Herr Benz how come his top-line cartridges don't come with
instructions?  I mean beyond the basic (but nevertheless vital) stuff 
about how to wire it up, how about some instructions on VTA, loading, tracking
weight - details like that. His answer was that at this stage of the game, 
anyone buying a top-end moving coil most probably knows what they are doing.  
Also, the top-end cartridges tend to have rather short runs so that the
expense of producing an instruction booklet cannot be easily amortized.

I was surprised to find that they don't use a record cleaning machine.
Alcohol is used to clean styli and records are given the occaisional
bath when they get too dirty.  No Stylast either.  Contrast that with
my own regimen of cleaning with the Nitty Gritty and Torumat fluid
before *every* play and religous use of Stylast on the stylus.  And I
know I'm not the only one who does this.

Both Herr Benz and Lukaschek were unfailingly polite and patient with
me throughout my visit, even though this was a busy and trying time
for them, what with the redeployment of the factory floor and all.
Nay, I would say they were positively enthusiastic to share their
vast knowledge.  But I was completely bowled over when Herr Benz
invited me to his home for dinner.  I mean aren't the Swiss supposed
to be, like, so reserved?  

That evening, over homemade cheese fondue *with garlic*, Herr Benz told me
a little of his history and a very interesting story it is.  Turns out
he's a fellow alum.  Yup, the guy is a Techer (graduate of Caltech).  
It's always nice to see a fellow alum doing something useful with his
life instead of frittering time away on trivial pursuits like the
Nobel Prize.  He came to Caltech to learn about aeronautical engineering,
in particular strain gauges (invented by another fellow Techer (alright, 
enough already with the alma mater boostering)).  

After graduation, he worked for an aerospace company in Los Angeles 
before transferring back to Switzerland to a job in the watchmaking industry.  
It sounds quaint now, but in those days, watchmakers would tout the quality of 
their wares by indicating how many jewels a watch contained.  And so it was 
that Herr Benz became a leading supplier of jewels to the watch industry.  The 
skills learned fashioning diamonds and rubies transferred directly to the 
manufacture of styli.  Coming full circle, Herr Benz has begun making 
chronometers, especially for aviators.  He's a pilot himself.  I told you
it was an interesting story.

-- ray