Picawood® by Pyon Sound
The only way that Pyon could make fine objects, like arm tubes and headshells, dimensionally stable, was to pursue a structure with many more alternating layers. With standard products, like Panzerholz, much thicker laminations mean there is less stability when using the product on a very small-scale. When you release the confining tension of various layers, above and below, natural wood fibers will start to relax somewhat. This is not a problem with large objects, like plinths, or bullet proof doors, but can create issues when trying to guarantee dimensions that will not change. With Picawood, many thinner plies are used, and are pressed at higher pressures for a longer time. The result is something that it stable, even in very small objects. For apples to apples comparison, here is an armboard made from 1.5″ thick Panzerholz (stacked, glued, then cut by the plinth maker), next to samples of Picawood. Both are rigid and dead, but the Picawood has advantages, especially in the world of arm tubes and headshells.
Picawood® is a specialized form of plywood made of thin plies, or veneers, of Finnish Birch, held together by oil-based phenol resins, and compressed under very high pressure for a specified time. The amount of pressure, and the time held under compression, is important for the curing process of the phenol resins. The process cannot be rushed. The result is an incredibly dense, rigid, rugged and machinable product that surpasses plastics and metals for many critical applications where minimal resonance and maximum strength is desired.
The order of production:
- Prepare and air-cure Finnish Birch wood veneers for thirty days in a drying room.
- Sort and select quality veneers by carefully screening for proper shape and pattern (at this stage, non-conforming veneers are discarded).
- Stack the selected veneers, alternating each layer at 90-degrees, crossing the grain patterns at right angles.
- During the stacking process, oil-based phenol resin is applied between veneers.
- Steam-pressurize the accumulated veneers with a 250-ton press, and air-cure for one week while maintaining pressure.
- While pressurized and curing, the thickness decreases by 35%. The original single veneer thickness of 0.9mm, or 0.035″, decreases to 0.6mm, or 0.024″.
- The final product is harder, but lighter, than Duralumin (aerospace-grade aluminum).
- Because Picawood® is a hardened, solid block of material, and is appropriate for precision machining processes (milling and turning), it is most often used for ultra-expensive precision instruments and aircraft materials.
- Although compressed, and very rigid, the internal structure preserves the connective fibers of natural wood, and is ideally suited for absorbing and dissipating resonance and vibration.
- Picawood® is arguably the best critically damped structural material for audio equipment applications.
Carefully chosen 1mm thick Finnish Birch veneers are cured in a drying room
Available colors are walnut-brown or charcoal-black
Walnut-brown stained Birch wood veneer
Stained Birch veneers are dried at ambient temperature for 30 days
After the drying process, Birch veneers are piled up to obtained a desired thickness, applying phenol resin (adhesive) between veneers. The piled-up and glued Birch veneers go to the hydraulic press. The Birch veneers are compressed by 35% in thickness. For example, fifty 1mm thick Birchwood plates are used to obtain a 30mm-thick panel.
The hydraulic press used to make Picawood®
The hydraulic press in action
The hydraulic press applies 250 tonnes (kGf/cm3) for hours to obtain the desired hardness
The hardness of Picawood® is being measured
The meter shows a reading of 67.8. In comparison, aluminum’s hardness is around 50, while stainless steel is around 70. Picawood® is harder than aluminum and almost approaches stainless steel.
This block of Picawood® shows one half that has been compressed at 250 tonnes, while the other half has not been compressed.
A precision-cut amplifier chassis made of Picawood®, the best amplifier chassis money can buy. Absolute non-conductivity eliminates eddy currents. The resonance and vibration damping are second to none.
The photo shows the tonearm wands which are mad of various wood materials. Two arm wands from the right are made of brown Picawood® and charcoal black Picawood®. Picawood® arm wands boast excellent performance, if not the best, in supporting the cartridge and headshell for the best possible vibration and resonance control.
This photo shows headshells made of various wood materials. The second headshell from the right is made of Indian Ebony wood. The three other headshells are made of Picawood®. The finger clip is also made of charcoal black Picawood®. The Picawood® headshell is surely THE BEST HEADSHELL money can buy. It offers excellent rigidity (much harder and stiffer than aluminum), but is lighter than aluminum or magnesium. At the same time, it provides the best damping properties, absorbing and eliminating vibration generated by the cartridge.