The Galibier Bearing
The Best Bearing we can Make - fitted to all Galibier turntables
(alien not included)
- Damping stray vibrations entering or leaving the bearing.
- Cooling - as vibrational energy is converted into heat, the increased
volume of oil circulates and dissipates the heat into the bearing housing.
Frequently Asked Questions ...
What kind of oil should be used in the bearing?
The short answer is that low viscosity oils are ideal for use in a
Galibier bearing. Thick oils have the effect of suppressing dynamic contrast, pace, rhythm, and timing.
We find this unacceptable in a product with high aspirations.
Lubrication has been a source of much obfuscation, propagated in part by
certain Scottish turntable companies. Much time has been spent discussing this
question on several analog equipment lists and several lubrication engineers
weighed in on the subject. Ultimately, everyone had their own prejudices but
certain principles arose from the conversation:
- Additives like colloidal graphite (what makes the Linn and Merrill oil
black) are acceptable but unnecessary
- Stay away from detergent additives
- Match the oil viscosity to the tolerances of the bearing
Goal #1 - to Protect the Bearing From Mechanical and Thermal Stress
With respect to temperature stability, one needs to consider the application
and how over-engineered even the least sophisticated of these products is for
use in a turntable bearing.
Heat in a turntable bearing, from a petroleum engineering
perspective is virtually non-existent. The massive bearing housing and large
sump capacity (8.5cc) further minimizes stress on the oil.
During our early experimentation with bearing with thrust surface materials, we observed
that a Galibier bearing takes about 4 hours to warm up. This further demonstrated to us
how little thermal stress is placed on the oil.
Goal #2 - Mechanical Stability - Viscosity
A bearing requires lubrication with some minimum degree of viscosity in order to remain geometrically stable.
If the lubrication is too thin for the bearing's clearance, you will experience rocking which will manifest
itself in speed instability.
Frequently, higher viscosity oils (think of STP motor oil additive) are used to bring loose or worn
bearings back into spec - once again matching the viscosity to the bearing clearance.
On one analog list, a user of a VPI TNT reported great success by packing the bearing with lightweight
bicycle grease. Others have reported success using grease in the bearings of EMT's and Garrard 401's.
With the extremely fine tolerances in our bearings, you will have great difficulty getting even 50
weight oil to pass through the clearances. Don't even consider trying to get bicycle grease to pass through
these fine tolerances.
Goal #3 - the Music
Now that we've addressed the health of the bearing as well as ensuring that it is stable (doesn't rock), our
focus can return to the end-game - the music.
Realize that any mechanical drive system is a resonant system.
We can tune this system optimally by recognizing its components and varying one or more of them
Motor, its torque and mechanical moment of inertia
The controller circuit - how quickly it responds to the dynamic demands placed on it.
The drive interface and its compliance:
- Belt drives - the compliance of the belt
- Idler drives - the idler wheel's compliance
- Direct-drive - the torque characteristics of the drive system
Changing any one of these variables will affect what you hear (especially as far as timing is concerned), and
not necessarily for the better.