all know that the turntable, the arm and the cartridge interact
in a very delicate way. The diamond tip picks up the tiniest information.
The analogue source has far more bits than the digital formats!
The minute movements are transformed into electrical signals by
the coils in the cartridge and send to the amplifier.
Turntable-arm-cartridge should be seen as an entity. That is why
one commercial arm performs better than another in conjunction
with the same turntable (motor unit) and why a given cartridge
does not always deliver as pure a signal with certain arms and
I designed this arm with a Denon DL 103 cartridge in mind and
in practice. The DL103 is a very fine cartridge not only if one
takes the price into account. There are many audiophiles and music
lovers who have been frustrated by the use of some expensive and
fragile cartridges that prevented them form relaxed listening
because of the constant worrying about the fragile cantilever,
the expensive thin shaped diamond tip and in some cases the collected
dust in an open cartridge. That is not to say that the high quality
and high end cartridges need to be a pain in the neck. They perform
extremely well if the owner takes care and has the right equipment
in order to display the virtues.
cartridge performs best with a specific tone arm. Not only because
of the sonic qualities of the arm, but also because of the effective
mass of the arm. The effective mass should be perfectly suited
to the cartridge that you want to use. The first SME was built
at the beginning of the stereo era for the new Shure lightweight
pick up. Fidelity Research have built cartridges that had to be
adopted by arms with an effective mass as high as 30 gr. And they
built the arms to go with these cartridges.
For the Denon DL 103 the English magazine Hi-Fi Choice states
16 gr. as the maximum effective mass of the arm. To those 16 gr.
the weight of the cartridge has to be added. That means that more
than the 16 gr. (without counting the weight of the cartridge)
will put the resonance too low. The sound will then have a lumpy
quality and impair speed. On the other hand too little mass will
mis track the groove and blur mid and high frequencies, and will
give the sound some vagueness at the same time because of the
fact that the fundamental frequencies of instruments are not well
controlled and thus not well transmitted. Just to remind you once
this DESIGN you can find out and adjust the effective mass of
the arm tube without the need of adding weight as is usually done
by means of a sliding metal ring or screwing some weight in between
the cartridge body and the head shell. At the same time you will
keep the arm as long as possible. My impression is that the 'unused'
part of the arm tube at the other end of the pivot has a significant
influence on the sonic properties notwithstanding the fact that
the tube will be secured above the pivot and the propagation of
sound waves will be stopped to a certain extend because of the
tight connection with the short tube with knife bearings.
For every 10 mm of the aluminum tube that I used I had to calculate
a weight of 0.6 gr. For the screws used to fit the cartridge and
the small acrylic mounting plate some 2 gr. should be added. The
result was that an effective mass of the arm of 16 gr. could be
calculated as follows: 16 - 2 = 14 : 0.6 = 23.3 cm.
N.B. A friend of mine told me that I had not calculated the effective
mass according to the appropriate equation. Therefor I will recalculate
it later and write in this section about it.
The total length of the arm tube used by me was 38 cm. I tried
the arm at 28 cm which gives a mass of 16.8 gr. without counting
screws, mounting plate (and of course the cartridge). At first
hearing the sound was well controlled but was lumpy and muddy.
So I had to experiment and detect a more suitable mass. (See at
the end of this article.)
CALIBRATION AND SPRING
arm lift you can use an existing arm lift or you can think up
something as I did. My lift works as a lift but is not suitable
for positioning the cartridge on the right spot.
For calibrating the arm (overhang, horizontal tracking angle)
you should use a template from a manufacturer, a shop or you make
one yourself. Be sure to firmly secure the arm at the base after
alignment. Also the arm tube should be secured very firmly so
that a swinging mode can not occur and an accentuation of some
frequencies is impossible.
Now it is time to calibrate the vertical pressure. I use the arm
in its dynamic version. That is the version with the spring. That
spring has to be very supple but at the same time not too long.
A long spring has to be shortened when you have shifted the tube
to the back, that is when you have shortened the effective length
of the arm tube. You will notice that. If you do not do that the
spring and the ring n the arm tube are likely to touch the platter
When calibrating the tracking weight first of all the sliding
ring on the arm tube to which the spring is attached should be
close to the pivot so that the spring does have no influence and
the weight of the ring (little as it may be) has no significance
either. Balance the arm with the counterweight. Than move the
ring in the direction of the cartridge and the spring will get
some tension. Use a tracking weight balance of Nagaoka, Shure
or any other make and move the ring so far that the scale indicates
2.25 gr. for the Denon; if you use another cartridge you will
have changed for another effective arm mass and you will have
to use the proper tracking force indicated by the manufacturer.
All moving parts that are not well secured and thus can vibrate
have an influence on the sound. In order to eliminate any resonance
provoked by the ring and the spring you should take a tiny bit
of balsa wood or a very small part of a match and push that in
between the arm and the ring so that the ring cannot move or vibrate.
Originally I had damped these resonance by means of tape. But
when a collector from abroad came to visit me and we listened
to various records we decided that the sound was too well damped
and the mid band was not open enough, which as I discovered later
was caused by the small pieces of black plastic insulation tape
in combinations with the mass of the arm which was too high. So
finally I adjusted the arm and reduced the effective length of
the arm tube to 25 cm.
In time you will also discover that the tracking force needs adjustment
as well as the side thrust (bias).
VERSUS STATICALLY BALANCED
the maximum of mass for a given cartridge will especially be of
benefit to the reproduction of recordings from the nineteen fifties
en sixties, the era when tone arms were much more heavier. All
of a sudden I became aware of the fact that Samson François
must have been playing on a grand piano manufactured by Erard
(or Pleyel?) when recording the Four Ballads of Chopin (Columbia
FC 1041, 10"). And it is amazing how good the piano tone was captured
in those days. Also you can notice that Jorge Bolet probably plays
a Baldwin on his Remington recordings.
Using a spring for the vertical down force has the advantage that
the pressure is practically always the same. There is just a slight
variation when warped records are played. As said earlier the
variations in pressure when using a statically balanced arm are
much greater because of the swinging of tube and counterweight,
while with a spring this movement is suppressed, (better controlled).
If you use a gimbal bearing as in the Thorens arms in combination
with the spring, the arm will play records in whatever position
the turntable is in. Nevertheless you should however always adjust
the turntable so it is level.
OF TIP AND COUNTERWEIGHT
the proposed design you will see that the pivot is at the same
horizontal level as the diamond tip. On top of that the counterweight
is positioned underneath that horizontal plane. So this arm can
also be used as a statically balanced arm and will perform well.
I de-coupled the counterweight by means of a few centimeters of
rubber insulation (shaft) taken from an old, yet supple interconnect.
I put this insulation over the bolt which holds the counterweight.
The amount of play between counterweight and bolt depends on the
tightness of the insulation and the sort of rubber or plastic.
performance of a tone arm depends also on the sonic virtues of
the turntable itself and if they match the arm's behavior. The
sort of turntable mat is of great significance. If you use an
acrylic mat (à la Goldmund) on a rather heavy platter you
need high quality amplifiers that perform extremely well in the
top end of the audio band. If you use a rubber mat distortion
will be increased. If you use a turntable mat of glass the top
and bottom ends of the audio band will be much cleaner but also
"lighter" in nature.
I must say that I am very pleased with this arm. The sound has
weight and transparency, nevertheless the audio curve appears
very even and straight. Transient response is very good. The soul
of the music is conveyed in a very realistic way.
aim was to have a long tone arm in order to minimize the lateral
(horizontal) tracking angle. Also I wanted the arm to have a long
tube, as long as possible. First for reasons of sound and secondly
a long tube would make it possible to find the optimum effective
mass for a specific cartridge without adding weight to the wand
or by inserting blocks or little plates between the cartridge
and the head shell (mounting plate).
article is meant as an inspiration to those who want to try building
a tone arm themselves; not necessarily in the same way and with
the same parts as I did.
It is possible to use lighter aluminum tube but it has to have
enough rigidity to avoid bending (it easily does even if you do
not see it).
Eventually I will try to improve my arm by finding and using a
higher grade of tube which is used in medical equipment for example
or I will try to get hold of a carbon fiber tube combined with
aluminum as is used for arrows even though I am a fan of aluminum,
more than of carbon fiber. But the combination will have the benefit
If you have questions and/or comments send an e-mail.