edible zone
- March 16, 2004
Let’s begin by considering what the audio philosophers have to say:
I mistrust all systematizers and I avoid them. The will to a system is the lack of integrity. - Frederic Nietzsche
The whole is more than the sum of its parts. - Anon
Everything counts in large amounts. - Depeche Mode
Trust your ears. If it sounds good it is, and if it doesn’t, it ain’t. - Anon
Tuesday evening, 10:00 pm, the lights are out and vinyl is spinning
on the platter. In my left hand is a single malt whiskey and in my right
some freshly roasted espresso. I sit and sip slowly, alternatively from
the left and then the right. The LP for tonight is one of my favourites,
‘Concorde’ by The Modern Jazz Quartet. As the stylus goes down the walls
of my apartment melt into the darkness and I find myself transported to
a dimly lit, vast expanse of space. Guitars, vibes and vocals emerge
eerily from the shadows. Audio ‘chiaroscuro’, the play of light and
shade. Subtle shifts of color and texture. Drama. Contrast. I hear with
great clarity how notes develop in time, their attack, sustain, and near
endless decay. It’s not long before my mind is lost somewhere
out-in-space; it’s as if I am swimming, immersed in a amorphous volume
of liquid sound. Oh yes, I have much luck, there is good electricity
tonight!
This article tells a story about turntable DIY. It’s the
story of my very own time machine with which I willingly curve both
space and time. At the ‘clunk’ of a switch I can travel almost anywhere
I like. If you’re anything like me, audio is more than a polite academic
interest, it’s a way of survival. Perhaps I should admit from the start,
I have not owned many turntables. My first was an AR spring suspension
deck, later came the Thorens TD124, and now I enjoy spinning with a
beautiful old Garrard 401. Oh, and since I am currently studying abroad
for the next three years, I temporarily spin with a nice Thorens TD160.
Perhaps I should also add that I got into tweaking classic rim drive
turntables mostly by way of circumstance. Being a university lecturer, I
don’t have, or want to have, the spare cash that is required to buy
those to-die-for super decks, such as the Air-Forsel, the Platine
Verdier, or the Teres. If I owned ones of these I probably would not
waste my time with my ‘old clunker’, or would I? Many audiophiles have
commented on the ‘very good’ sound that can be had from old rim drive
Garrards and Thorens, provided they are set up correctly. I read these
reports with much interest, and so when I started down this road I was
fully aware I had chosen a cost-effective path. I was hoping to get good
results but did not expect to land up where I find myself today. After
two years of tweaking away on my beloved Garrard 401 I can truly say the
results are way beyond my wildest expectations. The moment of truth
usually comes when one has the opportunity to visit audiophile friends,
to hear their systems, to be honest when comparing notes and so to
reflect upon one’s own sound at home. I have had the good fortune to
hear some rather fine vinyl playback systems, and my usual experience
these days is to say, ‘yup this dudes deck does this, this and probably
even that better than mine, … but on the other hand, mine …’. Yes
indeed, I can honestly say a properly set up Garrard is not easily
embarrassed, and it does some things so darn well I’m still waiting to
hear another deck that can compete!
This makes me a rather contented analogue fan, with spare change
in the pocket for more vinyl, which brings me to my first point. High
performance turntable are finely crafted musical instruments, and just
like the famous master violins, each TT deck out there has its own
unique character. I find it rather sad to read audiophile magazines with
reviewers who still believe the old, tired myth of ultimate sound. If we
are to believe the editors of Hi Fi News, for example, then a five
hundred watt Krell power amplifier driving Wilson loudspeakers
represents the current pinnacle of audio transparency. Well I have heard
this kind of gear, and to me it possesses a very distinct character
indeed. Krell amps sound like Krell amps, which in itself is hardly a
bad thing. It all depends of course whether you like this kind of sound
or not, and I should add this type of sound does absolutely nothing for
me. But my real point is this: when a listener seems unable to discern
the fundamental character of a given system, pretending instead that it
sounds perfectly neutral and transparent, then I must assume a serious
case of hearing loss. With this comment I will leave the mythical idea
of transparency and neutrality behind to those who are wilfully deafened
by what they wish to believe in their minds and so cannot hear from the
heart. Instead my point of departure starts with a respect for the
fundamental character of a given piece of gear. All audio devices have
their own unique character. Audio should not be about illuminating sonic
character. Rather we should ask whether this character speaks in a way
that is musically profound or not? Identifying the fundamental character
of a given component is important, especially for tweak-freaks such as
myself, because no matter what we do to this piece of equipment, we are
not going to change this fundamental sound. Tweaking and setup is mostly
about refinement and compensation for things that may be absent so as to
take the sound to the next level, BUT the fundamental character of the
sound will remain throughout. This observation is rather important
because if one is going to spend time and energy on a turntable project
then one needs to be clear from the start that the turntable in question
is one which possesses a character that one can identify with, that one
likes, and therefore is a character that one believes is worth
developing. It is also necessary to be critical as to what is on offer
and what is lacking so to establish some clear objectives as to where
one wishes to go.
Through time I was lucky enough to pick up a
Thorens TD124, a Garrard 401, then finally an early silver-grey grease
bearing Garrard 301, my prize possession. So the first step was to mount
these turntables onto test plinths and to take a listen to hear what
they had to offer. The big disappointment of the three turned out to be
301. This deck had a dark and ill-defined sound. I messed around with it
for quite some time but with no luck. My mate Gerald explained that to
his ears the 301 had a ‘claustrophobic’ kind of sound and I had to
agree. I was kinda pissed! The grease-bearing 301 is a real vintage cult
item, and besides it was the only one of the three that I paid real
money for (well almost real money). Add to this its drop dead gorgeous
looks …. Arrrghhhh!! But there was no cheating on the sonic truth. By
contrast, the 401 proved to be a winner right from the start. I can
still remember that first day when I plugged it in. Nothing was setup
right, but the glorious character of this deck immediately shone
through. There was a boldness and thrilling sense of presence, like
nothing I have ever heard before, add to this a real musicality and a
quiet, mysterious background. Wow, so this is the sound the Garrard
freaks are always going on about. Well I’m converted, amen.
The
Thorens TD124 also has much to offer. In some ways I agree with what
many say, that the 124 has a touch more air and grace, but it also lacks
the marvellous authority of the Garrard. The choice was not difficult to
make, it had to be the 401. As an aside, I wish to add I have had the
good fortune to email a few vintage turntable fans, and virtually
everyone out there has their own rather different stories to tell. In
the end I have come to the conclusion that the sound from idler wheel
turntable has a lot do with their condition. Let’s be clear we are
talking about rather old equipment here, and despite their tank-like
construction, parts do wear with time. So in my case, my strong
preference for the Garrard 401 might be based on nothing more than the
fact that it is the best preserved of the three.
As most probably
know, the Garrards were sold without a plinth. In the old days the
popular idea seemed to be that owners cut a hole into the
built-in-cupboard in their lounge and mounted the deck there. This must
have been disastrous for sound, and so it is hardly surprising that in
the new era of spring suspension decks, many a Garrard was passed over
and scorned for its poor sonic performance. In this way, it is told how
these British classic’s left Europe and made their way to Japan where
rather more intelligent audiophiles knew exactly what to do with them,
and the clever Japanese have been high fever for Garrard’s ever since!
Setting up a Garrard is mostly a question of building a solid and sturdy
plinth, this and the more regular choices of appropriate arm, cartridge
and support. During the last two years I have paid close attention to
all aspects of this undertaking and have experimented with no less that
three (possibly four depending on how you count things) different
plinths. The first MDF Lorricraft style plinth was ok, a second highly
damped, constrained-laminate experiment was a complete disaster, and the
last being a medium mass 36 mm thick Baltic birch ply plinth was the
winner by a large margin. In the process I was forced to do a lot of
theorizing about turntable design. I also felt I learned quite a bit
from the process, as well as from my new-found friends. So maybe one day
I will go out and buy that to-die-for super deck after all, but having
spent some time doing TT DIY I believe I have learned things about
analogue playback that I could not have learned any other way. In a way
I feel it is sad that more audiophiles don’t experiment with DIY because
for me it has proved to be a necessary way forward in understanding the
art of quality sound.
Turntable design has much to do with
managing vibration, and we may observe that there are at least four
primary sources of vibration that need to be considered. The first and
by far the most important is the vibration generated by the stylus
itself. Then we also have the vibration coming from the main bearing of
the spinning platter, the vibration from the motor, and lastly the
vibrations that come from the outside world. There may well be further
forms of vibration, but for the purpose of this article I wish only to
discuss these four. So lets start with vibration from the stylus. Now it
should be obvious that we are primarily wanting to amplify the vibration
of the stylus. The arm and table itself are just supports to this
intention, or are they? Many would argue that we wish to amplify the
stylus vibration and NOTHING else, and hence everything else, the
platter, arm, and support must be completely damped and vibration free.
Whatever the merits of this intention, I personally find this approach
to be rather optimistic and hence fundamentally flawed. The real truth
of the matter is that everything in the physical universe vibrates all
the time. At the atomic level it is well understood that we have these
particles whizzing around, little packets of energy dynamically
interacting within space. Whilst in the world of everyday life, where
our bodies move, and where small diamonds vibrate, a similar pattern
appears to hold. A lorry drives down the road outside, and I can feel
the walls of my apartment vibrate. It is quite impossible to stop the
power of vibration, and this is a basic fact of relevance for the
natural reproduction of sound. We want to enjoy the musical vibrations
that are trapped on those precious black disks, we want to hear the
vibrations, not cancel them. Fighting the interactive facts of vibration
makes no sense to me, and as I have discovered an overly damped
‘vibration free’ design can risk sounding the way one might expect, that
is dead and lifeless. Instead I believe the art of turntable design
concerns the channelling of energy in a way to produce a lively and
‘natural’ sound. As the Beach Boys aptly put it, we want: "Good, good,
good vibrations!"
Once again a turntable might best be understood
as musical instrument, finely tuned for good tone. An illuminating
comparison is that of an electric guitar. With e-guitar the sound comes
from an electrical pickup which detects the vibration of metal strings.
One might assume that the body and neck of the guitar are irrelevant,
because it is only the strings that vibrate and the pickup which does
the detection. But nothing is further from the truth. A Fender
Stratocaster sounds the way it does because it has a body made from ash,
a bolt-in neck from maple, a finger board from rosewood, and a light and
somewhat lossy bridge. A Gibson, by contrast, has a very different tone
due to its glue-in neck construction, heavy mahogany body with solid
bridge. Mounting a fender pickup on a Gibson will alter the sound, but
it will be apparent that one still has the characteristic sound of a
Gibson, if not married to the thinner character of the strat’s single
coil pickup. This is true because the vibrating strings set the entire
ensemble of the guitar into a vibrating network. The musical energy
flows in a loop down the string, along the neck, into the body, through
the bridge and back into the string. Change any one element in this
ensemble and you will change the entire resonant characteristic of the
sound. And, quite naturally, exactly the same is true for a turntable.
Stylus, arm, platter and plinth play in concert with each other and, as
is well understood, a change to any one item is effectively a change to
all.
Returning once again to the wisdom of those infamous audio
philosophers: "Everything counts in large amounts’", means we need to
carefully study all aspects of the vibration loop that operate on a
turntable. We essentially have a loop comprised of the turntable itself
together with its platter, the mat, the stylus, the tone arm and the
plinth which connects the arm back to the turntable. In my case three of
these elements are already defined, the turntable is the Garrard 401,
the arm is an SME 3012, and the cartridge is a Denon DL103R. And if I
might say, this combination is a rather classic arrangement which does
seems to work really well. Visiting fringe Japanese audio web sites will
quickly demonstrate that this exact combination has a way of turning up
alongside flea power single ended triode amps, such as those built
around the lovely 45 or 2A3 DHT’s (directly heated triodes) and
efficient loudspeakers, be they horns, open baffles or transmission
lines. This amounts to a truly excellent recommendation in my opinion.
I have not owned many tone arms but I have heard various arms in
other systems. All I can say is I will NEVER sell the SME 12" arm
because it is a stunning piece of engineering art. The SME 3012 brings
an alive and free kind of sound, with a smooth and magical midrange
which seems to work rather well with the more powerful and authoritative
sound of the Garrard. My friend Gerald who, unlike me, has owned many
tone arms, and who presently is the proud owner-user of a lovely ET air
bearing linear tracker (Yummy!), helped me to appreciate the family
sound of various types of tone arm design. Fixed gimbal bearing tone
arms can perform rather well at the frequency extremes, giving excellent
bass and detail, are well controlled, but are not always the most
gracious or tonally agile. On the other hand, loose bearing designs such
as uni-pivot’s and knife edge arms (such as the classic SME’s) may lack
a bit of bass power but tend to have a more alive, gracious, loose, free
and airy presentation, and certainly the SME3012 does sound this way.
With audio it is often a good idea to combine opposites so as to achieve
a subtle and sophisticated balance of virtues. Anyway whatever the
reasons may be, I can definitely recommend SME3012 together with the
Garrard, enough said.
This leaves us with only two further
primary elements with which to play within the vibration loop; the mat
and the plinth. Mats are a fascinating topic all of their own. There are
many schools of thought, around which I have done much experimentation.
In my experience, mats have a dramatic effect on the overall tonal
balance of the sound, and I even think some name brands are in part
sonically defined by their approach to this topic. The theory goes that
we are listening to a vibration interface which dissipates energy from
the stylus into the vinyl, into the mat, into the platter and then in
reverse as the vibration bounces back. The astonishing bit is that mats
seem to sound exactly the way you might expect them too! A glass mat
gives excellent transient attack but can also tend to sound hard,
brittle and a bit ‘glassy’ in the highs. Felt is airy and free in the
highs but rather grey everywhere else. Spongy rubber (such as
sorbothane) has rich colours in the low mids and powerful bass but also
tends to be overly warm. Acrylic sounds very clean but possibly a bit
anti-septic, possibly even a bit too clean, a bit ‘plastic’. Cork in
some ways comes close to felt because it is airy and light but is far
less grey through the mid-band and, overall, more natural sounding even
if it does lose a bit of transient attack. Through time I have come to
adopt a somewhat hybrid approach, because I find that combining
different materials together can help to create a more sophisticated
kind of sound. And so after many hours of careful experimentation I have
chosen to use no less than three mats. The first mat which sits directly
onto the naked aluminium platter is a thin 2 mm layer of pure cork. Next
I have a 4 mm disk of acrylic, machined for me by my machinist friend.
And lastly I have a DIY ‘ringmat’ which is loosely based upon a real
Ringmat I saw at a friends place (note: since mine is a loose diy
version I can’t vouch that it is as good as the real thing …
nevertheless it sounds pretty darn good to me …). Perhaps I should add,
the Garrard, fortunately, has a long spindle which is good if you go for
multiple mats the way I do. My multi-mat approach attempts to gradually
decouple the LP from the platter below. This strategy works rather well
on the Garrard because it helps to isolate the LP from mechanical noise
induced into the platter via the rim drive mechanism. The result is a
much more airy, alive and detailed kind of sound. One which retains a
natural tonal balance across all frequencies. The Garrard has moved
quite a few notches in the right direction with these simple mats.
Perhaps I should comment here on my design intentions. The Garrard
has glorious dynamic power and awesome bass. Some Garrard dudes seem to
go all out to optimize these strong points. Hence they opt for high mass
and rigidity at every turn. Heavy stone plinths and glass mats are a
common choice. Whilst I respect this approach, my way of thinking is
somewhat different. I find the Garrard has such good bass there is
little benefit to optimizing it still further. Instead I want to
retrieve a degree of air, of life and subtlety that is simply not
available from the standard Garrard sound. My kind of multi-mat approach
means a small loss in terms of bass and dynamics, but the gains in terms
of life and air are a truly worthwhile trade-off in my view.
The final part of the vibration loop is the plinth itself. As already mentioned, I experimented with no less than three or four plinth arrangements and in the end settled for a medium mass birch plywood plinth (36 mm thick). Baltic birch ply, from Finland, may be expensive but it looks beautiful and sounds beautiful too.
The birch brings an agile and fast kind of sound, which can be
characterized as tonally sweet and fresh. MDF may have a darker
background but also sounds somewhat grey and flat. A good friend of
mine, Peter, has done a lot of experimenting with audio equipment
supports. He has come to the conclusion that MDF and chipboard are
thoroughly non-musical sounding materials and as such constitute
inappropriate choices for high end audio. From my own experience with TT
plinths and loudspeaker cabinets, I don’t disagree. Birch plywood was
famously chosen for the classic BBC monitor loudspeaker designs, and
that’s a good recommendation if ever there was one. The simple reason
you don’t find birch used much these days has probably a lot to do with
attempts to cut corners and to lower manufacturing cost. MDF is a cheap
synthetic material and it certainly sounds that way to me.
I
mentioned previously my constrained laminate plinth experiment which was
a total flop. That story is almost too sore to tell because it involved
two weeks of solid labor toward a carefully designed and finely executed
construction process which proved to be a big waste of effort. The
constrained laminate was REALLY WELL damped. I wrapped it with my
knuckle and the vibration just sank into the depths of the slab. I was
expecting great results, but in fact the sound was a total disaster.
Dark, confused, slow and with an over abundance of surface noise. Highly
damped plinths may be attractive, in principle, but this experience
terminated my curiosity for good. By contrast the simple birch ply
plinth has proved to be very musical and I can’t imagine wanting to
change it in the near future. On the other hand, high mass plinths from
slate, marble or granite are a tempting option which I would love to try
one day. On the down side, I just can’t get used to the idea of a 40 kg
turntable that requires two or three men to move from one position to
the next. Besides I once heard a 401 in a granite plinth, at a friend’s
house, and I am not so sure this high mass approach produces the free
spirited kind of sound I am after.
The vibration loop discussed
above, might be described as positive vibration because it is the
vibration we are going to be amplifying, this is the vibration we will
be hearing through the loudspeakers. Tuning this loop is mostly a matter
of choosing the right compliment of materials. I believe, all in all, we
are looking for some elusive and ideal combination of weight, rigidity
and compliance. In my case birch ply, cork, paper, and acrylic have
provided the key to unlock a natural, well balanced, yet also colorful
and free kind of sound. I don’t tolerate analytical, dry and grey sound,
however ‘detailed’ or ‘neutral’ it may pretend to be. No doubt others
listen in a different way. The fun bit about TT DIY is you can select
the materials that capture your imagination and use them to move your
heart. TT’s are after all rather personal devices, so what better way
than to fine tune your own stairway to vinyl heaven.
The
remaining three sources of vibration I now wish to consider are
primarily negative forms of vibration. These vibrations are not part of
the audio signal, and as such need to be suppressed as far as possible.
The first of these three concerns the main bearing. The platter is
spinning and this means there is friction in the platter bearing, and
this friction is the source of significant concern. Let’s remember the
LP sits directly onto the platter and there is generally a rigid
connection between the platter and the bearing, so any vibration from
the bearing is going to make its way quite directly into the stylus.
Springs and cones are not going to help in this regard, whereas
something like a Ringmat might be just what the doctor ordered (I
personally think the Ringmat is a breakthrough in vinyl technology … get
one if you dare …!). The early Garrards are famous for their legendary
grease-bearing design, and it is well known that Japanese Garrard freaks
will pay huge sums of money for an early grease-bearing Garrad 301. This
means the grease bearing 301’s are now rather rare these days and rather
expensive too. Fortunately I got my early silver-grey grease bearing 301
for a decent price; it’s a real blast living in postcolonial Africa. The
Garrards are pretty much built like motor cars. They comprise a kit of
parts which bolt together and you can more or less trade parts between a
301 and a 401. Buying more than one deck is not a bad idea, in my view,
because spare parts are very expensive and hard to come by. A little bit
of cannibalism is ok, provided it keeps the main system spinning. With
this understanding in mind I made careful comparisons between my 401
with its original oil bearing and with the grease bearing taken from my
301. Well, all I can say is I love the grease bearing mounted onto my
401, because the grease bearing seems to take the Garrard sound a few
steps further, bringing substantial improvements to bass and dynamics
contrasts. The grease bearing also significantly lowers the noise floor,
making surface noise even quieter than is the case with the regular oil
bearing, and this is an improvement you just have to love. Being a bit
more philosophical, however, I would need to add that there is much to
recommend from both bearing types. Both are very well made and both
sound very good. The oil bearing seems to have a somewhat more lean kind
of sound, and is possibly even a little more airy in the highs. And so
quite frankly I can well imagine some listeners might prefer the oil
bearing; I, however, rather like having a bit of grease lightning!
Having taken the grease bearing apart, cleaning and re-lubricating
it, I can happily say that it is a small masterpiece of precision
engineering. Furthermore, my grease bearing is the only bearing, from
amongst all my other rim drives, that has absolutely no play, no play
whatsoever. It is really easy to check for play in the main bearing of a
TT. Just place both hands firmly to either side of the platter and try
to rock it from side to side. I have tried this on no less that four oil
bearing Garrards, and four Thorens TD124’s (ok, you guessed it, I had to
visit some friends who share my rim drive fetish!), some of which were
in lovely condition, and all had significant play in the main bearing.
Not so with the grease bearing from my old 301. No matter what you do,
it won’t rock. And when you turn in with your fingers, it moves so slow
and so smooth, you just know this is something really special.
The next source of negative vibration I wish to consider is the motor.
Having a good, powerful, yet low vibration motor is very important for
good sound. If we look at classic belt drives from the 70’s and 80’s,
such as the Linn Sondek for example, we can see that this aspect of TT
design was rather ignored in the hey day of high end vinyl audio. Sorry
to say, but the Linn motor is pretty crappy, however you look at it. The
Garrard, by contrast is blessed, or cursed, by an enormous beast, which
supplies clean agile power and this keeps the platter spinning with
spot-on accurate speed. The theory goes that bass notes force the stylus
to vibrate so vigorously that friction generated in the groove slows the
platter down. Most medium mass belt drive turntables, such as the Linn,
Pink, Logic, et al., are said to suffer from pitch instability induced
by low frequency vibration of the needle. Not so with the Garrard,
thanks to its strongly coupled friction drive (i.e. rim drive), and that
monster-motor. But like most good things in life, there is also a down
side. The down side is the powerful motor tends to shake the hell out of
the deck. And from this we probably get the characteristic Garrard
sound, awesome dynamic presence, but also a lack of refinement in the
highs.
Reducing vibration on the Garrard motor is rather
important, and results in a massive improvement to the sound. But before
I discuss how I have treated this issue, I wish to first explain a bit
more about the way the Garrard is built. Something I never realized
before owning a Garrard is the ingenious way in which the motor is
mounted onto the main chassis of the deck. The motor is suspended on six
highly compliant springs. We have a typical three point suspension
design, with each point supported by two springs, one going up and the
other down. The motor is literally floating in the air, and the
isolation provided by these springs seems to be very good indeed. Tap
the motor and it bounces up and down just like the platter on your Linn.
What many don’t realize is the Garrards in fact do have a 3-point spring
suspension design, only it is not the platter that bops up and down, but
rather the motor. I might add that the 401 seems to have a much better
spring suspension than the older 301. The 401 motor is also a fair bit
bigger than the 301 motor, it consumes less energy (12 watts versus 16
watts, if I am not mistaken), and puts out way less vibration too. The
401 motor is a much improved design, no question about it. Mmmm ….would
love to have one of those new 501 air bearing motors … oh well, that’s
me dreaming again.
I said the Garrard motor shakes the hell out
of the deck, but this is too much of an exaggeration. The Garrard motor
has lots of energy, and so it ain’t low torque, low vibration in the way
that we might expect from a standard belt drive 24 pole micro Philips
motor kind of affair. But it also ain’t so high vibration as it might
look given its marvelous size. The direct remedy is rather simple.
Dropping the supply voltage from 230v down to say 180v has a remarkable
effect, which greatly reduces vibration. All you need is a low wattage
light bulb wired in series with the motor. The lower the wattage the
lower the voltage you will get. A 60 to 40 watt bulb is probably fine.
As can be expected, lowering the motor voltage has a pronounced effect
on the sound. As the voltage goes down so does the dynamic presence, but
once again you gain refinement and air in the highs. I find 180v to be
about optimum, and 150v is too low because the deck starts to spin in an
irregular fashion. Further improvements can be had with a proper ac
power supply. I built the excellent supply designed by Prof. Mohammed
Imbabi. His design uses an analogue Wien Bridge to generate a very clean
and smooth sine wave, which is subsequently amplified by an IC power op
amp and lastly stepped up with a power transformer. Mohammed’s design
works a real treat revealing yet further levels of subtle nuance and
detail. On Baroque ensemble we can now hear fine grained textures
together with an exhilarating sense of timing. With the power unit
generating a clean ac supply and the voltage dropped to around 180 or
170 volts we are left with very little vibration. In my case, the open
plinth arrangement allows me to put my finger on the motor whenever I
wish, and I can assure you with the measures just described the
resulting vibration coming from the motor is very low indeed. Anyone
committed to getting the best from their Garrard simply MUST use a
proper ac power supply such as the one described here.
This issue
of motor vibration leads me to a further point. Many Garrard fans argue
that these decks need to be mounted on a very heavy plinth so as to
absorb vibration from the motor. I however, think this reasoning is
flawed. If you think about it, vibration will always follow the path of
least resistance (the law of conservation of energy). The Garrard motor
is already very well isolated from the chassis via its three point
spring suspension. This, in effect, means the motor is isolated from the
mass of the plinth, because very little vibration is going to get from
the motor into the chassis via the springs. The weak point in the design
is the rim drive, because here we have a fairly rigid contact between
the motor and the platter. If energy is going to flow from the motor
into the stylus then it is not going to go via the chassis, the weight
of the plinth and the arm, but via the rim, through the platter and
directly into the stylus. So if you think about it, no amount of weight
applied to the chassis is going to alter the direct flow from rim to
platter to stylus. A better approach is to attack the vibration at the
source. Kill the vibration by lowering the voltage and provide a cleanly
regenerated 50 Hz sine wave.
The last negative vibrations I wish
to consider are the vibes transmitted through the floor and air. We are
after all listening to music, music which thanks to the Garrard is being
reproduced with considerable force. This force is also feeding back into
the deck, and robbing us of those finer moments where one may well wish
to be transfixed by the subtleties of advanced musicianship. I want to
hear the bow on the string, the hammer on the piano, and the tongue on
the reed of the clarinet. So we need to isolate the deck from the
noise-ridden environment that surrounds it; as much is well understood
by most vinyl fans. Many believe that high mass can achieve the desired
effect. I am not convinced. I think high mass may well absorb energy and
lower its fundaments frequency, but it also traps that energy rather
than dissipating it. As previously mentioned, my apartment is pretty
heavy, but this does not stop it from responding to the truck that
drives down on the other side of the road. In my view we need some form
of compliance in order to isolate the deck from the world around. After
reading a rave review on the Symposium roller balls, in Listener
magazine, I was convinced that this roller ball concept is nothing but
pure genius. So I got my machinist friend to machine me a set of six
aluminium blocks, each with a smooth spoon-like depression.
A solid steel, or even better, tungsten, ball-bearing sits between
two such depressions, and three of these ‘roller ball’ double block
networks support the underside of the TT. If you push a TT which sits on
these roller balls it will wobble as if supported by jelly. That free
floating jello-wobble never ceases to amaze unsuspecting non-audio
conscious guests. With these free floating balls beneath your deck,
vibration from the outside world is converted into a low frequency
rocking motion, hopefully in the 3 Hz region, which is quite in-audible
to the otherwise sensitive stylus. The idea was developed as a way to
protect skyscrapers collapsing in the event of an earthquake; giant
balls are used at the foundation of these buildings which transfer
earthquake shock waves into harmless low frequency vibration. If the
idea works for skyscrapers in an earthquake zone then why not for your
TT in the presence of high voltage Led Zeppelin bass and drum riffs?
Just think about that one for a good few second. In practice the roller
balls came up tops. They bring new levels of refinement which may be
heard across all frequencies, and may have brought the single most
significant improvement compared with all the other mods discussed here.
Well that’s about it; the story of my turntable. It really does
sound rather good, even if I say so myself, and I can’t imagine ever
wanting to sell it. Maybe I will buy that dream TT one day, but the ol’
Garrard will stay even if just to remind me of the good times I had
thinking and tweaking away during those happy two years. Now please
excuse me … the 401 calls … and where did I put that singe malt, and
where are those freshly ground coffee beans … ?
End
PS: J. Noble's other DIY components can be viewed in the Systems Gallery