Kuzma Turntable Theory Brochure
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USEFUL INFORMATION
USEFUL INFORMATION
Setting up a Turntable - Theory
Supports
Levelling
Adjustments
Tonearm Mounting
Cartridge Mounting
Cartridge Adjustment
Fine Cartridge Adjustment
Practical fine VTA & Azimuth Adjustment
USEFUL INFORMATION
Much useful information can be found in our product instruction manuals. Here we provide some basics.
Setting up a Turntable - Theory
urntables fall into two basic categories, ie those suspended by springs and non suspended turntables with
minimum isolation provided by elastic feet.
Suspended turntables usually resonate in the range of 2-6 Hz, which is below the resonance of the tonearm /
cartridge assembly. The suspension system filters vibrations above the resonance of the system but is very
sensitive in the resonance range of the system and also allows through vibration below the range down to
zero Hz.
o avoid heavy movement of subchassis, platter and tonearm, some sort of damping is used in the spring
suspension. This restrains movement of subchassis and improves sound quality but it also lowers filtration of
the system, which accepts more vibration at frequencies above the resonance.
Systems with minimum elasticity (with rubber feet or other exotic material) also resonate but at a hi
of between 10-50 Hz. They are usually heavily damped to prevent movement between motor and platter but
are sensitive to vibration and acoustic feedback.
he system will be less sensitive to vibration if it has lower resonance and less damping but will, accordingly,
allow more movement to take place between motor and platter and the sensitivity of the tonearm to this
movement will cause unstable sound.
he use of a highly damped system will give a stable drive, but the additional vibrations will bring the sound
forward and cause loss of definition in lower registers.
ny turntable will be less sensitive to vibration if it has a high mass. A low mass chassis is only useful in that
it creates higher resonance with less stored energy, causing smaller movements. Such systems fail to
her level
reproduce low frequency energy, filtering it out and creating an artificially
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cleaner sound which can help a simple system to apparently perform "better".
Supports
he best turntable support is a rigid stand which does not have low frequency resonance to interfere with the
resonance of the turntable suspension. A stand is sensitive to vertical floor vibration but, being raised, will
also be sensitive to horizontal vibration, which will interfere still further with the horizontal resonance of the
chassis and ultimately affect drive and tonearm performance.
If the turntable is on a rigid wall support it will be insensitive to vertical vibration but more susceptible to
horizontal ones.
In practise there is always a mix of both types of vibration along with torsional ones.
Stabi Reference suspended turntable for example, will effectively filter out frequencies above 3-4 Hz. With a
mass of 40 kg, and its own resonance of 2.2 Hz, if placed on a wobbly stand it is likely to resonate in the
range of the turntable resonance. A very rigid stand will resonate above the turntable resonance thus
effectively filtering out higher resonances.
he turntables own suspension will, additionally, filter resonances in a lower range and the damping will
prevent chassis movement. If a suspended turntable, without damping, is placed on a stand we have to
ensure that the resonance of the stand is well above the turntable's own resonance. In this case the turntable
will filter out the stands horizontal movements. If the resonance of the stand is below the turntable
suspension resonance, then the whole turntable will move, creating problems in drive. The tonearm will also
move separately, creating wow. In practise the resonance of suspension, tonearm and support will be quite
close and will interfere with each other. There can even be different resonance in the stand in different
directions, ie back and forth can be different from side to side.
urntables with minimum suspension do not have this problem but will be more sensitive to all vibration of
the stand. Turntable and stand resonance will usually be in the ran
very rigid stand with high resonances, self damped in the stand is better.
dditional supporting platforms can work very well with some turntables, while creating problems with others.
platform with air suspension and low mass will audibly resonate and cause a confused sound. To decrease
the resonance, mass must be added. The best platforms combine high mass and low resonance in the range
of 2-3 Hz. It is useful if the mass used is a rigid supporting plate, which dampens vibrations in the turntable
structure itself but, once again, care must be taken to avoid resonance of the stand and turntable itself.
e of tonearm resonance, so once again, a
Levelling
he turntable should be level on the stand by use of spikes, feet, screws or adjustable legs on the turntable.
dding mass, adding the platter for example, will affect the suspension and alter the horizontal level. If the
turntable frame is horizontal and the platter parallel to this then all is well. If the turntable has minimal
suspension then this will not be a problem.
Adjustments
Manufacturers instruction manuals should be used when adjusting turntables and tonearms.
Tonearm Mounting
If mounting a tonearm on a turntable without a precut armboard, ensure that fit is correct by measuring the
distance from the pivot to tonearm , being careful to leave space for counterweight and checking that height
allows for lid closure. In suspended turntables care must be taken to fix cables in such a way that it does not
interfere with the suspension. Turntables with damping and a heavy subchassis are less sensitive to this
problem.
Cartridge Mounting
It is necessary to be very careful during this process, to use good screwdrivers or Allen keys and a good pair
of tweezers. Once the cartridge is fixed in the headshell ensure that the cartridge is parallel to the sides of
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