Advantages of the construction and materials used in the PETROF P 159 Bora grand piano
Rim PETROF 159 Bora grand piano
The rim is a Petrof original design.
The inner rim is laminated with 9 ply’s of solid beech and birch lamellas and is CNC machined for high accuracy.
The outer rim is sandwiched from solid alder core and outer HDF lamellas with veneer.
The inside facing is veneered horizontally with Ebony Makassar.
The total rim thickness is 5,8 cm.
A solid rim ensures long term tuning stability and regulation stability. A firm CNC machined rim supports the proper crown of the sound board, which produces the precious Petrof tone. Rare Ebony wood on the inner face of the rim gives the noble appearance that is deserving of a Petrof grand piano.
Frame posts
The Petrof frame consists of 3 longitudinal spruce posts.
The joints of the posts and rim are dove tailed (fish tailed) and doweled with beech hardwood dowels.
The entire wooden frame is CNC machined to insure an accurate fit to support the crown of the sound board.
The firm frame with solid posts provides a high form stability of the frame, tuning and regulation stability.
Legs
The legs are a Petrof original design.
The legs are made with a solid beech core, an outer layer of alder, a Gabon counter veneer, and an outer decorative veneer.
The front legs are 625 mm in length.
Strong leg construction ensures high piano stability when being played dynamically. The legs are proportioned adequately to the size of piano.
Iron plate
The iron plate is produced in the Czech Republic.
The iron plate is made from grey cast iron, wet sand casted, and hand finished; then it is CNC machined for an accurate fit.
Each plate is finished in the new dynamic gold color.
CNC machining ensures high accuracy of string scaling and accurate fit to each piano. Our new plate color enhances the beauty and noble look of the Petrof grand piano.
Hardware fittings
The hardware is a Petrof original design.
The hardware is solid polished brass, lacquered, and stain resistant.
All the hardware fittings are maintenance free.
Pinblock
The pin block is made from special Multiplex type compressed beech plywood with a density 800 –850 kg/m3, laminated using very strong moisture resistant laminate glues.
The pin block is highly resistant to climatic changes, providing stable torque of tuning pins and high tuning stability.
Soundboard
The soundboard is a Petrof original design.
The soundboard is made from fine European spruce.
It is symmetrically crowned, and wedge tapered from 9 mm in front to 7 mm in back arc.
The traditional symmetric crown and wedge tapering of the soundboard gives the piano good acoustic performance in the whole tonal range and induces typical tone of Petrof grand pianos.
Ribs
The ribs are a Petrof original design.
The ribs are made from fine European spruce.
They are symmetrically circular shaped, the tips are machine fitted.
The straight corner cross rib (cut off bar) is made from solid beech wood. It is CNC machined to the form of soundboard crown.
Traditionally circular shaped ribs support the symmetric crown of the soundboard and conduce to the typical Petrof sound.
Bridges
The bridges are a Petrof original design.
The treble bridge utilizes a solid beech body with a genuine ebony cap in high treble section.
The bass bridge has a solid beech body with a foot bridge.
Both the bridges are blackened, machine notched and hand drilled for the pins.
The ebony bridge cap is used to most efficiently transfer of high frequencies to the soundboard. The bridges design contributes to the wonderful European sound of the Petrof.
Scale
The Bora uses agraffs in the bass and low treble and front and rear pre-tuned duplexes in high treble.
Petrof utilizes laser positioning of its duplex bridges (frets).
The Bora uses double string hitching of plain strings.
Using of agraffs and duplex scaling adds richness to the tonal color of the piano.
Tuning pins
The tuning pins are made of steel then nickel plated for prolonged service life.
The tuning pins are of the best quality and they are corrosion resistant.
Strings
The steel wire of treble strings and steel core of wrapped strings are made by Röslau Germany, and Mapes USA.
The copper wire for winding is made by Degen Germany.
The longest bass string is 1150 mm.
Strings are made from special string wire of top world quality.
Hammer heads
The Petrof utilizes Abel or Renner hammers made in Germany with walnut or hornbeam moldings and hornbeam hammer shanks.
Abel and Renner hammers are one from the worlds best, made from very special hammer felt. These hammers enable Petrof to obtain a wide scale of tonal color and power.
Dampers
The Bora is equipped with Petrof dampers. There is used the world top damper felt Laoureux France.
In this grand piano dampers are used which are produced by Petrof. Used French felt is a guarantee of the highest quality of the dampers.
Action
The action used in this piano is Petrof original.
The wippen rail and hammer rail are made from aluminium profile.
The action parts are made from hornbeam.
A Petrof grand action is generally rated as a fast, reliable, with good repetition. Special profiled aluminium action rails are very stable also in changing air humudity.
Keyboard
The Bora keyboard is another Petrof original design.
Petrof keyboards are made from solid European spruce.
White and black key tops are acrylic Polyplex from Sweden.
The entire keyboard is individually balanced.
Petrof keyboards belong among the top quality keyboards in the world. Polyplex tops provide a pleasant feeling when playing.
Key bed
The key bed is a Petrof original design.
Petrof construction, spruce sandwiched, between beech hardwood veneers.
A beech hardwood insert is inset in the spruce core in legs and lyre area.
The key bed thickness is 47 mm.
The key bed is additionally reinforced by a strong solid wood rail on the bottom of the key bed.
Key bed is CNC machined for a perfect fit and high accuracy.
A reinforced key bed ensures high stability both in play and regulation, it provides a feeling of reliance allowing the pianists to perform to their full potential.
Pedals
The Bora has three fully functional pedals made of solid polished brass.
The middle pedal has sustenuto function.
The pedal system is braced with two steel attached braces to insure stability when playing.
Construction, materials and function of the pedal system are fully comparable with that of other high-end grand pianos.
