AP 275 grand piano

AP 275
PETROF presents the very top model made in its workshops. The ANT. PETROF 275 is brand new concert grand piano. The flagship designed for the big concert halls and to fulfill the demands of todays best pianists.
Traditional family brand ANT. PETROF was chosen for this flagship. Antonin Petrof, founder of the company, used this abbreviation on his first grand pianos and now, after 150 years, the brand is reborn.
Nothing but top quality is allowed in this new grand from PETROF. It aims to the highest posts, the concert halls and most demanding players.

ANT. PETROF 275 grand piano is result of 5 years of development and research in PETROF R&D department. The whole construction is designed from scratch. Over 50 innovations are used in the construction of the piano, 2 of them were patented.

Only 1st class materials of European origin are used in this instrument. More than 75 % of the operations are made manually and all the operations are made with the great care. And of course it is 100 % made in PETROF factory in  Hradec Králové, Czech Republic.

Explore the ANT. PETROF brand at www.antpetrof.com.
Technical specification
AP 275 celek1
AP 275 zhora
AP 275 celek3
AP 275 det3
Pages: 1 2 3 4 5 6 

Inner rim

Original Petrof construction.

Inner rim is a conglomerate of preformed beech mouldings wide 50 mm, layered in 4 layers each above other. These layers are shifted each to other that way, that longitudinal joints of mouldings don´t meet in nearby layers. Inner surface of inner rim is veneered with beech counterveneer thick 2 mm, varnished with transparent lacquer.

Outer rim is laminated from birch plywood laminas, its thickness is 30 mm. 
Total thickness of side wall of the grand piano (Inner rim + Outer rim) is 82 mm.
The rim is braced inside with 4 longitudinal and 2 transversal braces (beams) that are oriented crosswise (see below).
Cross block (belly rail) is made from beech wood. It is reinforced with steel „T“ profiled rail that is embedded to the groove of cross block, sealed with Epoxy resin.
The components of wooden frame of the piano are CNC machined. Wooden frame is hand-built.
Unusually robust wooden frame provides the grand piano Ant. Petrof 275 high firmness and ensures longtime stability of the shape of the piano, longtime tuning stability and action regulation stability what is precondition for excellent  performance of a piano player.
Highly robust wooden frame keeps stable crown of the soudboard that retains stable quality and colour of the tone of the piano.
Inner rim braces (beams)
Original Petrof construction.
The inner rim is braced inside with 4 solid wood longitudinal braces, fan oriented and 2 transversal braces that are oriented crosswise, in parallel with the keyboard.
First three left longitudinal braces and both stransversal braces have a spruce wood core, bottom and top surface are laminated with beech flanges. Right treble longitudinal brace is made from solid beech wood. All braces are embedded to the inner rim. They are overlapped in their crossings.
Overall 6 braces of the rim, interlaced each with other, ensure high stability of the shape of the rim, that provides tuning and regulation stability, soundboards crown stability, therefore stability of sound quality and tone colour.
Original Petrof construction.
Soundboard is made from solid European spruce wood. The board is diaphragmatic tapered from 9 mm in the centre to 6,5 mm along its perimeter. Total surface of the soundboard is 2,253 m2, vibrating surface inside soundboard mouldings and cut-off bar (left corner cross rib) is 1,879 m2.
The soundboard is reinforced with 16 ribs and with 1 curved cut-off bar (left corner curved cross rib). Crown of the sounboard is asymmetric.
Original structure of the soundboard provides high sound power of the piano in its whole tone range and characteristic romantic tone colour. Grand piano Ant. Petrof 275 will sound well in big concert halls.
Original Petrof construction.
The soundboard is reinforced from lower side with 16 ribs, made from European spruce wood. The ribs are asymmetric shaped and support asymmetric crown of the soundboard.
Arc shaped cut-off bar (corner cross rib) is laminated from beech wood laminas.
Asymmetric crown of soundboard and asymmetric shaped ribs give the piano high sound power and characteristic tone colour.
Original Petrof construction.
Bass and treble bridge are made from solid maple wood.
Bass bridge is lightened by horizontal holes to reduce inertial mass and for faster transmission of strings vibrations to the soundboard.
Upper surfaces of the bridges are hand-notched, hand-drilled for bridge pins and graphitized.
Maple wood of the bridges enables perfect transmission of strings vibrations to the soundboard. Lightened bass bridge reduces loss of energy of vibrating bass strings and enables exceptional sound of bass tones.
Key bed
Original Petrof construction.
The key bed is three-layer sendwich of spruce wood veneered with beech veneer.
There are beech wood inserts placed in spruce core of the sendwich in zones of mounting of lyre and legs.
Thickeness of the key bed is 47 mm.
The key bed is additionally reinforced from below with bulky solid beech wood rails. One longitudinal and two transversal.
Bulky firm key bed of Ant. Petrof grand is form stable. It enables high stability of the instrument, providing long lasting stable action regulation and certitude for pianist.
Pin block
The pin block is made from special compressed beech plywood Multiplex type, with density about 800 – 850 kg/m3.
The pin block is high resistant to climatic changes, providing stable and even torque of tuning pins and high tuning stability.
Iron plate
Original Petrof construction.
Iron plate is made from grey cast iron, cast to wet sand, made in Czech Republic. It has 6 longitudinal and 1 transversal brace.
There are 5 big windows in hitching zone. Surface of the plate is hand-worked. Iron plate is CNC drilled, painted with gold metalic lacquer.
CNC drilling of iron plate ensures high accuracy of strings scale. Exact speaking length of the strings and duplexes creates conditions for optimal strings vibrations and production of bright exact tone.
Largely open hitching zone of the plate enables good sound propagation from the soundboard.

Iron plate support
Original Petrof construction.
The iron plate is supported in its fore part with adjustable steel bolt against cross block (belly rail) of wooden frame.
Supported iron plate increases its form stability and then also tuning stability.

Strings bedding
Original Petrof construction.

The strings are bedded into brass gold-plated agraffes in bass and middle zone. There are two capo V bar fields in treble zone of iron plate. Hard steel wire is inserted to the edge of capo bar. All strings are single hitched.

Single hitching of the strings increases tuning stability and enables to play the piano even when one string cracks. Steel capo bar contributes to long and bright sound of treble tones.
Original Petrof construction.
Grand piano Ant. Petrof 275 is equipped with front duplexes placed in front of capo bar in the range of tones d2 – c5 (54 – 88) and with rear duplexes placed behind the treble bridge in the range of tones d1 – c5 (42 – 88). Duplex frets are gold-plated. Front and rear duplexes are tuned to harmonic frequencies.
The application of duplexes takes a share in rich sound of the piano in the whole tone range.
Original Petrof construction.
Steel core of wound strings and flat strings are made from first-class string wire Röslau Germany. Copper winding of wound strings is made from special copper wire Degen Germany. The longest bass string is 2090 mm long.
The grand has 9 one-string bass tones, 7 two-string bass tones, 3 three-string bass tones and 69 three-string flat choirs.
The strings of Petrof grands are made from world best string wire.
Tuning pins
The tuning pins are made from nickel-plated steel.
The tuning pins are top-grade quality, stain resistant.
Renner Germany.

Wippen rail is made from vertically oriented plywood Multiplex type.
Hammer flange rail is made from solid beech wood.
Action parts are made from hard and tough hornbeam wood.
Grand piano action Renner is generally rated as one of the world best. It is reliable and fast. Renner actions are most frequently used actions in supreme grand pianos in the long term.
Renner Germany.

Dampers Renner Germany are used in this grand piano. They are made from hornbeam wood and top-grade quality damper felt.


These dampers are rated as ones of the world best.


Hammer heads

Renner Germany.


Renner hammer heads are made from special hammer felt of top-grade quality, with hornbeam mouldings and hornbeam hammers shanks.

These hammers are rated as ones of the world best. They take a share in wide dynamics of the piano sound and rich coloured tones spectrum.

Key board
Original Petrof construction.
The keys are made from European spruce wood.
White key tops are made from polymethacrylate Polyplex Sweden.
Black keys are made from genuine Ebony wood.
The keys are individually balanced.

Grand piano Ant. Petrof 275 is equipped with the Petrof key board made from European spruce. Its quality is proved by 150 years tradition of its production. Ebony wood of black keys provides pleasant feeling when playing the piano.
Original Petrof construction.
Grand piano is equipped with 3 solid brass pedals. Left pedal (piano pedal) to shift the action and keyboard, middle pedal (sostenuto pedal, prolongement pedal), right pedal (forte pedal, sustain pedal) to lift the dampers.
Construction, materials and function of Ant. Petrof 275 pedals are full comparable to pedals mechanisms of other top-grade grand pianos.
Original Petrof construction.
The legs of Ant. Petrof 275 grand are made from one block of beech plywood Multiplex type including the legs consoles (heads). The legs are mounted to the piano with steel legs locks.

Robust structure of the legs without any construction-joints ensures extraordinary stability when playing the piano.
Fittings, hinges, castors
Original Petrof construction.
All the fittings, hinges and castors are designed by Petrof and made from solid brass and steel, polished and painted with protecting lacquer.
Solid brass fittings are protected by varnish against corrosion, they are maintenance-free.

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President's word

Zuzana Ceralova PetrofovaI am honored that grand and upright pianos of PETROF brand have been a source of delight not only for top-class piano players, composers, students and their teachers, but that they with their romantic and sophisticated tone have also been touching the hearts of music lovers all over the world for more than 150 years.
Mgr. Zuzana Ceralova Petrofova
President of PETROF Group
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© Copyright 2016 | PETROF, spol. s r.o | Na Brně 1955 | 500 06 Hradec Králové | ČESKÁ REPUBLIKA

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