Used to adjust the pitch of musical instruments. Setting up a musical instrument using gStrings

The invention relates to the design of a device for tuning musical instruments. A device for tuning stringed musical instruments contains a phonogram with twelve sound tracks, rotating on a seven-speed pulley. In this case, each pulley stage is made with given dimensions and rotates at a given speed. The device contains a motor that imparts rotation to the pulley using a drive belt put on a pulley stage and moved from one pulley stage to another, and an adapter with a light bulb located above the phonogram with the ability to move relative to it. In this case, the signal from the adapter is sent to a photocell installed under the phonogram, and through a low-frequency amplifier it is transmitted to the device’s speaker. The technical result achieved in this case is to increase the accuracy of tuning a musical instrument. 3 ill.

Drawings for RF patent 2383937

The claimed invention relates to a device for tuning musical instruments and is used for precise tuning of all types of stringed musical instruments. The device has exceptionally high tuning accuracy and produces 72 precisely tuned musical sounds. Currently, musical instruments are tuned using a tuning fork, and only one string is precisely tuned, and the remaining eleven strings of other octaves are tuned by ear. At the same time, even the most experienced tuners make large errors, and a poorly tuned musical instrument irritates the ear and distorts the beauty and content of a musical work.

A reed tuning fork is known for tuning musical instruments (see SU 153169 A1, class G10G 7/02, publ. 01/01/1963), made in the form of a round body bearing on the surface the musical notations of musical tones, and containing a voice bar with several reeds, a mouthpiece and an adjustment dial for switching to a certain tone or musical intervals, while the reeds are located along the chords of the circumference of the voice bar, and the adjustment disc is made in the shape of a truncated cone that interacts with the beveled edges of the body opening.

The known tuning fork does not allow achieving high precision tuning of a musical instrument.

The technical problem to be solved by the claimed invention is the development of a device for tuning stringed musical instruments, which allows achieving high tuning accuracy.

The problem is solved by using a device for tuning stringed musical instruments, containing a phonogram with twelve sound tracks, consisting of six octaves and rotating on a seven-speed pulley, each of the steps of which is made with given dimensions and rotates at a given speed, a motor that gives rotation to the pulley using a drive belt put on a pulley stage and moved during operation of the device from one pulley stage to another, an adapter with a light bulb located above the phonogram with the ability to move relative to it, while the signal from the adapter is sent to a photocell installed under the phonogram and through a low-frequency amplifier transmitted to the device speaker.

The diagram of the device is shown in Fig. 1 (side view) and Fig. 2 (top view). Musical sounds are extracted from a phonogram with twelve audio tracks, consisting of six octaves (72 sounds in total).

Figure 3 shows a phonogram made on X-ray film. The phonogram 3 rotates on a seven-speed pulley 1 and has seven steps with strictly defined dimensions and strictly defined rotation speeds. The pulley rotates from a synchronous motor 4. A belt drive 8 goes to the pulley stages. The accuracy of the adjustment of the entire device depends on the motor driving the pulley. The pulleys are ground with a rotating motor to the required dimensions. In this case, the diameters of the phonogram pulleys are 21, 21-22, 47-23, 81-25, 23-26, 73-28, 32-30 mm. All pulleys are manufactured with an accuracy of +0.01 mm. Above the phonogram there is an adapter 5 with a light bulb from a flashlight 6. Under the phonogram, the adapter has a photocell 7 installed. When the device is operating, pulsating light falls on the photocell through the rotating phonogram, the resulting signals are amplified by a low frequency amplifier (LF) and enter the speaker. The ULF is used two-channel, two-contact, with a power of up to 10 watts. In this case, a foot pedal is connected in series to the wires going to the ULF to control the volume.

The drive belt from the motor drive pulley is located on the thickest 30 mm pulley of the seven-speed pulley 1. The motor and the light bulb located above the first four-character audio track are turned on, while the soundtrack rotates at a speed of 16.33 rps. To determine the frequency of the sounds produced, the number of revolutions is multiplied by the number of characters in the audio track, and we get 4 × 16.33 = 65.4 Hz. This frequency corresponds to the sound of the C major octave. Next, we move the light bulb to the next track of the phonogram, which also has 6 characters. Accordingly, we get 6×16.33=98 Hz. This frequency corresponds to the sound Sol of the same octave. Then we move the adapter to the next tracks and get the same sounds for the other octaves Do and Sol. The most recent track has 192 characters. It corresponds to a frequency of 192×16.33=3136 Hz, corresponding to the sound Sol of the fourth octave.

Under the sounds of the C and G signals, we tune the strings of all seven octaves and then move the drive belt to the next pulley stage with a diameter of 28.32 mm. Now the soundtrack rotates at a speed of 17.3 rps. We make the same calculations, multiplying the speed of rotation of the phonogram by the number of characters on the audio track, and we get the sounds Do# and Sol#. We tune these strings of all octaves, each time moving the motor, secure it with a screw and move the belt to other steps of the pulley.

To find out whether the string of the instrument being tested is accurately tuned, a guitar pickup is installed at a close distance to the string to determine the accuracy of tuning. A microammeter is connected to it through diodes. The maximum deflection of the instrument needle determines the quality of tuning of your instrument. Even if a person does not have absolute pitch, with the help of such a device it will be possible for him to tune any stringed musical instrument with an accuracy of 0.6%. The error in tuning “by ear” even by the most highly qualified tuner is at least 3-5%.

CLAIM

A device for tuning stringed musical instruments, containing a phonogram with twelve sound tracks, rotating on a seven-speed pulley, each of the stages of which is made with given dimensions and rotates at a given speed, a motor that gives rotation to the pulley using a drive belt, put on the pulley stage and moved with one stage of the pulley to another, an adapter with a light bulb located above the phonogram with the ability to move relative to it, while the signal from the adapter is supplied to a photocell installed under the phonogram and transmitted through a low-frequency amplifier to the speaker of the device.

Musical instrument tuner is a specialist in tuning various types of musical instruments: grand piano, upright piano, organ, button accordion, accordion, etc. The profession is suitable for those who are interested in singing and music (see choosing a profession based on interest in school subjects).

The tuner is a fighter on the invisible front; he is not applauded at concerts. But a significant part of the successful performance of musicians is the painstaking and highly professional work of the tuner. Without it, the instrument will not sound beautiful, spacious, expressive!

Features of the profession

Tuning a musical instrument is not only a technical operation of tightening the strings, but, one might say, an art that makes the instrument “sing.” For example, a piano has more than 80 keys, which, when played using complex mechanics, makes more than 200 strings sound. And the tuner must catch and adjust the sound of each string. In general, this instrument has 3000 parts, the interaction of the components of which determines the sound. Even the most insignificant deviation and inaccuracy in tuning - and the musician’s virtuoso playing will lose its expressiveness.

To properly tune a piano, in addition to specific hearing and sensitive hands, the tuner requires a set of 23 high-quality instruments, as well as knowledge of tuning systems: quarto-fifth and tertz-sext.

The functional responsibilities of tuners depend on their specialization in instruments: keyboards, winds, strings, plucked instruments, reed instruments, etc. Common features for all customizers are:

• tuning and adjusting musical instruments;
• checking their settings by playing and listening to individual pieces of music;
• identification and elimination of defects that affect the accuracy of adjustment.

Piano tuning, for example, is as follows:

• aligning the keyboard along the line of rising and falling keys;
• checking string clothing: string layout in choirs, their direction, height, angle of fit;
• checking the correctness of winding and fastening of the strings on the virbels, inspecting the condition of all the main components of the piano;
• tuning the first string of the “A” sound of the first octave using a tuning fork 440 Hz;
• tuning the note “A” to the first string of the remaining strings of the choir in unison;
• tuning of all string choirs in the temperament zone using fourths, fifths, major thirds and major sixths;
• tuning all strings of the instrument over the entire range, checking for octaves, thirds, fourths, fifths, sixths;
• intonation of the instrument over the entire range;
• technical work to identify other tool defects and eliminate them.

Pros and cons of the profession

pros

Demand, decent wages. After all, piano tuning is required at least 4 times a year. This is due to the change of seasons, when humidity and the presence or absence of heating change. In addition, subsidence of all tool materials also affects.

Minuses

Intense, labor-intensive, very painstaking and responsible work that does not tolerate negligence and unprofessionalism.

Place of work

Conservatories, concert halls, philharmonic societies, music schools, theaters, musical instrument factories, musical instrument rental companies, restoration workshops, private practices for tuning home musical instruments.

Important qualities

Personal qualities:

• Specific musical ear: the musician’s ear and the tuner’s ear are two different things. The ear of a true tuner lies in the ability to capture the slightest nuances of the sound of an instrument. And tuning the extreme registers requires especially trained ears and skills.
• Patience
• Concentration
• Integrity

Professional skills:

• mastery of intonation and tuning techniques, as well as musical literacy;
• knowledge of the basics of acoustics, physical characteristics of volume, sound duration, sound timbre, laws of string vibration, pitch standards;
• installation and adjustment skills;
• knowledge of the manufacturing technology and design of musical instruments, the purpose and interaction of parts, methods of performing forging work and tuning musical instruments.

Where to study to become a musical instrument tuner

• There are special schools for piano tuners, with full-time and even part-time courses. But initially, the tuner must have a basic musical education and experience playing any instruments.
• The profession of a musical instrument tuner can be mastered at factories for their production (special courses), in workshops for the restoration of musical instruments. In addition, in music schools, experienced masters prepare a shift of musicians who have an inclination for this profession.
• The highest level of training is the Theodor Steinway Academy for Concert Tuners.

Salary

Salary as of September 19, 2019

Russia 33000—90000 ₽

The salary of a musical instrument tuner depends on the place of work, region of residence and the condition of the musical instruments. In Moscow - from 40 thousand rubles. In large cities of Russia 25-30 thousand rubles. In private practice, the salary is piecework, depending on the number of orders completed. For example, the average cost of tuning a piano is 1500-1800 rubles in Moscow and takes 4 hours. Setting up a button accordion is much more expensive - about 15,000 rubles and will take at least a week. Setting up an organ takes 8 hours.

An important fact: the salary of an adjuster largely depends on his reputation. High-quality craftsmen are passed on “from hand to hand”; they are recommended to friends and acquaintances. Therefore, their income is stable and high.

Career steps and prospects

To become a real professional, you need long-term practice of at least 10 years. The greatest experience can be gained in a tool factory. The career of a tuner is a constant increase in skill from rank 4 to 12.

Professional holiday

In December 2003, the Ministry of Labor and Social Security of the Russian Federation adopted a resolution to include the profession of a piano tuner in the list of particularly important and responsible jobs.

1. Musical instruments are a whole world that has its own classification: type of wind instruments, class of woodwinds, reed group, family of saxophones, types - alto, tenor, baritone, bass, double bass. No matter how different musical instruments may be in shape, design, or size, they were all created for the same thing, so that musical sounds could be extracted from them.
2. Instead of pills - a portion of music!
3. Ancient doctors believed that there was no better way to maintain health than properly selected music. Modern medicine confirms this. Russian scientists V.M. Bekhterev and I.M. Sechenov noted the enormous influence of music on the nervous system, breathing and blood circulation. Music can either increase or decrease blood pressure, speed up or slow down your heart rate.
4. In addition to conventional treatment, German doctors recommend music therapy to patients: listening to classical music - Beethoven, Mozart, Chopin, Strauss, etc.
5. Melancholic people are cured by the sounds of the violin.
6. Phlegmatic people are shown viola music.

MEASURING EQUIPMENT

A. Grekov

DEVICE FOR TUNING MUSICAL INSTRUMENTS

Tuning musical instruments, as is known, is a difficult and painstaking task. Sometimes a lot of time is spent on this. But it can be greatly simplified if you use special electronic devices. One of them, developed by G. Markosov from Kislovodsk, is described below. It allows you to tune any musical instrument at home, the tuning of which is based on the principle of equal temperament, such as, for example, a piano, button accordion, or harp.

The device provides high tuning accuracy, allows you to expand and contract intervals in any part of the range, and adjust the instrument “on tap”. Tuning can be done visually, as well as aurally, using the unison-octave principle.

The operating principle of the device using the visual tuning method is based on comparing the height of the reference semitone with the height of the instrument's semitone. The comparison takes place on a cathode ray tube. In this case, the so-called circular scanning method is used, which is widely used in various fields of radio electronics.

In Fig. Figure 1 shows a block diagram of the device. It consists of a semitone generator G1, a limiting amplifier A1, a frequency divider D1, an amplifier A2, a phase shifter A3, a sensor E1, a signal amplifier A3 from the sensor, a mark former A4 and a cathode ray tube HI.

Switch S1 changes the frequency of the signal generated by node G1 and the conversion factor of the divider D1. Switch 52 selects the octave by connecting the input of amplifier A2 with the corresponding outputs of divider D1. Depending on the method used to tune the musical instrument - visual or auditory, the signal through switch S3 comes from the sensor to amplifier A3 (visual tuning) or from amplifier A2 to the sensor (auditory tuning). Switch S4 allows you to cover amplifier A3 with positive feedback, in the circuit of which the quartz resonator Z1 is included. In this case, the amplifier is disconnected from the E1 sensor and turns into a calibration generator.

Rice. 1. Block diagram of a device for tuning musical instruments

With the visual tuning method, electrical vibrations with a frequency corresponding to the selected semitone, amplified by node A2, arrive at the deflecting plates of the cathode ray tube HI. On its screen, the electron beam will draw a circle or ellipse. Since the frequency of the applied signal is relatively high, the movement of the beam is imperceptible.

The signal from the sensor, the frequency of which corresponds to the pitch of the sound, is amplified in node A2. Node A4 forms short rectangular pulses from it - marks, which are fed to the cathode ray tube modulator. These marks look like luminous dots on a circle (ellipse).

If the frequencies of the reference signal and the signal from the sensor are equal, then the marks will be motionless. Otherwise, they will begin to rotate in one direction or another. The degree of detuning of the instrument can be judged by the speed of movement of the marks.

The schematic diagram of the sample halftone generator and frequency divider is shown in Fig. 2.

The generator is assembled on transistor VI. Thanks to the deep feedback on direct and alternating current (through resistor R2), the high quality factor of the Y coil, the use of mica capacitors KSO-G, which have high thermal stability of parameters, and the weak connection of the generator with subsequent nodes, high stability of the generated frequency is achieved. This is also facilitated by periodic frequency correction using a quartz oscillator built into the device. The fundamental frequency produced by the generator is 3520 Hz, which corresponds to the semitone A. If necessary, the generated frequency is adjusted with variable resistor R4. They also raise or lower the tuning, which is necessary, for example, when tuning a musical instrument “on tap”.

To obtain another 11 semitones, the SI switch changes the generated frequency and divides it accordingly using a divider made on D-flip-flops Dl.l, D1.2, D2.1, D2.2, D3.1, D3.2. The divisor conversion factor changes depending on what semitone needs to be obtained. In table Table 1 shows the values ​​of the generator frequency, divider conversion factors and signal purity at the divider output.

The generator is connected to the divider through a buffer amplifier-limiter made on transistor V2, connected according to the source follower circuit.

Trimmer resistors RI2 - R14 equalize the size of the figure image on the oscilloscope tube at different octaves. The required “format” of the image is set with a variable resistor R15.

Rice. 2. Schematic diagram of the genepatorus of reference pulses and frequency divider

By shifting the variable resistor R15 through the capacitor C17, the signal is sent to a two-stage amplifier assembled on transistors V3 - V5 (Fig. 3). The second cascade is made according to a push-pull circuit and operates in AB2 mode. The circuits formed by the primary winding of transformer T1 and capacitors C.19 - C2I, the primary winding of transformer 72 and capacitors C22 - C24 separate the first harmonic from the rectangular voltage.

From the output of the amplifier, the signal through phase-shifting chains R22C25 and C28R23 is fed to the deflecting plates of the cathode ray tube Ш. From the secondary winding of transformer T2, a low-frequency non-inverted signal is supplied to connector XI, to which a sensor is connected when tuning the instrument using the unison-octave method.

An amplifier for the signal coming from the sensor is assembled on transistors V6 - V8 (connected to connector XI). Transistor V9 generates short rectangular pulses, the duration of which is determined by the time constant of the differentiating chain C35R37. These pulses are fed through capacitor C36 to the cathode ray tube modulator. At the same time, bright marks are displayed on its screen in “orbit”.

The device does not have a separate quartz oscillator used to correct the frequency of the emperor of exemplary semitones. Its functions are performed by the first two stages of the signal amplifier from the sensor. In the correction mode, the cascades on transistors V6, V7 are covered by positive feedback, in the circuit of which the quartz resonator Z1 is connected. Its own resonant frequency must be a multiple of the frequency of the half-tone A, since it is at this frequency that the correction is carried out. The device uses a quartz resonator with a frequency of 8800 Hz. Therefore, when correcting the frequency, 20 me-currents will be displayed on the first octave in the “orbit”, and 40 on the small octave.

To tune musical instruments, two sensors are used: acoustic type DEM-4 and magnetoelectric. The latter is made on the basis of the DEMSh-Im capsule. In the winding of the sensor (magnetoelectric), when the string vibrates near the pole pieces, electrical vibrations arise, which are transmitted to the device. When tuning is carried out using the electromechanical resonance method, on the contrary, vibrations coming from the device to the sensor excite the string.

The acoustic sensor is also reversible. It can be used both as a sound vibration emitter and a microphone.

The device is powered from an AC mains voltage of 220 V. It consumes power of about 10 W. All amplifiers are powered by a rectifier with a voltage of 22 V. A stabilized voltage of 9 V is supplied to transistors VI, V2 and microcircuits. The supply voltage to the anode circuits of the cathode ray tube (700 V) comes from a rectifier using diodes V9, V10, assembled according to a doubler circuit voltage.

The device is mounted in a housing measuring 215 X 195 X 100 mm.

Table 1

Rice. 3. Schematic diagram of a two-stage amplifier

Instead of the elements indicated in the diagram, you can use others with identical characteristics. The winding data of the L1 coil and transformers are given in table. 2. The inductance of the LI coil is 65 mH.

When setting up, it is necessary to very accurately select the frequency-setting elements in the generator, since the accuracy of the instrument settings depends on this.

Before carrying out work, the device must be pre-configured. After turning it on with a variable resistor R25 (“Brightness”), the lowest brightness of the image of a circle (ellipse) is obtained on the screen of the cathode ray tube. The SI switch is set to the A sharp position and the variable resistor R15 (“Size”) is used to achieve the largest circle size. Then connect the sensor and adjust the device. In this case, switch S4 should be in the “Correction” position, S1 - A, S2 - “First”. By rotating the variable resistor R1, the marks on the screen remain stationary. After this, switch S4 is switched to the “Operation” position and you can begin tuning the musical instrument.

In the process of tuning the instrument, it is advisable to repeat the frequency correction one more time. This will ensure high tuning accuracy.

When tuning a piano using the visual method, use both an acoustic and a magnetoelectric sensor. If an acoustic sensor is used, it is placed to the left or to the right (it doesn’t matter) of the keyboard. Out-of-tuning strings are muffled with a rubber clip. Switch S4 sets the corresponding semitone. While producing a sound by striking a key, observe the state of the marks and tune the choir strings one by one. If the marks, for example, move counterclockwise, then this means that the height of the string needs to be lowered. Conversely, clockwise movement of the marks means that the string tuning height needs to be increased.

After tuning the strings of one choir, tune the strings of the neighboring one, etc. It is advisable to start tuning with the bass strings.

Using a magnetoelectric sensor, it is positioned so that the pole pieces are close to the strings of the tuning choir. They excite the string by plucking and, observing the marks on the screen, tune it.

table 2

Partial tuning of individual voices of reed musical instruments - button accordions, accordions - is carried out using an acoustic sensor, which is placed near the instrument. By supplying air (no matter in what way), a sound of average volume of the tuned voice is produced. The sign of detuning is determined by the nature of the movement of the marks. If they move clockwise, then the pitch of the voice should be raised, if counterclockwise, the pitch should be lowered. To raise your voice, you need to file the tip of the tongue of the voice bar with a file. To lower your voice, you need to file down the base of the tongue. When tuning reed instruments that have a “filled” register, it is necessary to switch the register to a unison sound.

Organs, harps and other instruments with equal temperament are tuned in the same way as pianos and button accordions, but only an acoustic sensor is used.

The described device allows you to tune electric musical instruments. Moreover, in this case, you can do without sensors: the output of the electric musical instrument is connected directly to the device. If you plan to use a sensor, then only an acoustic one will do.

When checking the tuning of wind musical instruments, switch 52 should be in the position of the first or small octave, and S1 - in accordance with the selected semitone. The acoustic sensor is located two to three meters from the instrument.

A few words should be said about the auditory method of tuning by unison and octave sound, although it is inferior to the visual one. In this case, switch S3 is switched to the “Sound” position, and the acoustic sensor begins to perform the functions of a loudspeaker. The sound strength of the semitones is regulated by variable resistor R15. By turning on one or another semitone, the tuner tunes the instrument by ear.

For ... equipment as a functionally complete unit of computer technology, automation devices, measuring ... devices: ultrachemiscope ( deviceFor ...

The vibration frequency of the reed depends to some extent on the force of the air flow acting on the reed. Within the limits within which the air pressure in the bellows chamber of the instrument changes, the frequencies of the reeds can change up to 12 cents, while the tuning accuracy achieved by qualified craftsmen is a few cents. Therefore, reed instruments are tuned at a strictly constant air pressure, close to the normal average air pressure in the bellows chamber of the instrument, corresponding to the average sound volume.
The minimum difference in air pressure on both sides of the reed, at which vibrations can be excited in it, the so-called reed excitation threshold, is on average 4-25 mm of water. Art. and increases from low to high notes.

On reed excitation thresholds and tuning stability indicators

The minimum excitation thresholds are one of the indicators of the high sound qualities of reed instruments. The difference in the excitation thresholds of adjacent tones should not be noticeable by ear. Too high air pressure on the reed leads to disruption of its oscillations. In good instruments, the vibration breakdown threshold is 210-250 mm of water. Art. Setting at an average air pressure in the chamber leads to the fact that when the threshold pressure values ​​are reached, the vibration frequency of the tongue will deviate from the average value by 1 -1.5 Hz. The total amount of change in the frequency of the reed when the air pressure changes from the excitation threshold to the oscillation breakdown threshold is an indicator of the stability of the system.

Tempering area and setting steps

The pitch position of the tempering region in a reed instrument is somewhat different than in a piano - usually the octaves E 1 - E 2. This is explained by the fact that the octaves E 1 - E 2 are almost in the middle of the range of the melody of a reed instrument; beats in tuned fifths and fourths can be heard well in it.

The principles for constructing tuning plans are the same as those we described earlier for the piano. The total number of settings of a reed instrument is less than that of a piano.

There are rough tuning of the reeds with an accuracy of approximately 1/2 semitone, preliminary tuning of the voice bars with an accuracy of 1/12 - 1/16 semitones, and final tuning of the voice bars already in the instrument body with an accuracy of 1/32 semitones.

Features of grinding reeds to increase or decrease their frequency

The frequency of the reed is set by mechanically grinding the metal layer in various places along the length of the reed. In any case, removing the metal layer (at the preliminary setting - from 20 to 200 microns, at the final setting - from 10 to 80 microns) at the free end of the tongue increases the frequency of its own vibrations, and removing the metal layer at the fixed end lowers it.

The oscillation frequency of any system is proportional to the square root of the ratio of the rigidity of the system to its oscillating mass. Therefore, when grinding the metal of the tongue, the frequency changes depending on the parameter that has changed more as a result of this operation.

When grinding anywhere on the tongue, both its mass and rigidity simultaneously change. However, the extent of this change varies depending on the site of treatment. Machining the base of the tongue reduces the stiffness-to-weight ratio because it changes the stiffness more than the mass. Therefore, with this treatment, the vibration frequency of the tongue decreases. Reasoning similarly, it is easy to understand that when processing the top of the tongue, the frequency of its own vibrations increases.

Customization Tools

The tool for adjusting the reeds is simple. These are round-section scrapers, needle files (with a fine velvet notch), a thin steel plate-pod (sometimes called a golosnik, a builder) that supports the reed during its processing, hooks for lifting the internal reeds. You may need an anvil, hammer, pliers, knife and scissors.

At the preliminary setting, when a sufficiently thick layer of metal is removed, an abrasive wheel is used, driven by a small electric motor using a flexible shaft.

In factory conditions, adjustments are made in a special anechoic cabin, which is equipped with a blower - a device for creating the necessary difference in air pressure on both sides of the tongue (due to air rarefaction). The blower table is equipped with a special device for clamping the voice bar. Having established the vocal bar, it is first stimulated by pinching with the help of a vocal support.

Preliminary tuning is carried out in unison using the control (reference) reeds. When placing a support under the inner tongue, you must ensure that the tongue does not jam or become deformed.

Behavior of the tongue after mechanical treatment, relaxation of internal stresses and gluing of the husky

The pitch of the reed changes during mechanical processing, which creates stress in the body of the reed. Their relaxation leads to a subsequent change in rigidity at the point where the reed is attached and, as a consequence, to a change in the pitch of the sound. During processing, the reed heats up, and as it cools, the voltage and pitch of the sound also change. As a result of relaxation phenomena, the sound produced by the reed increases quite quickly after its tuning is completed; This increase is different for different reeds.

Gluing a husky causes the opposite change in frequency - a decrease in sound. This operation to some extent compensates for the increase in sound caused by the relaxation of mechanical stresses. Fine adjustments are carried out after gluing the husky. If the reeds are tuned by ear, then they use control of the beat frequency, which for the tuned intervals is the same as for the piano.

Currently, there are special devices that significantly facilitate the process of pre-tuning in a production environment. In this case, the frequencies of the reeds are compared with reference frequencies produced by an electronic generator, and the degree of tuning is monitored visually on the screen of the cathode ray tube.

What affects the accuracy of tuning

The pitch of the reeds is influenced by the resonators and the body of the instrument, so the final, final tuning is done only in the body of the instrument in which these resonators will be installed. Here it is necessary to check the condition and quality of gluing of the kid flaps on the strips that affect the setting.

The accuracy of the reed adjustment on the voice strip is influenced even by the tightness of the strip installation on the resonator and the reliability of sealing the strip around the perimeter with rosin-wax mastic. If the installation is not tight and the seal is depressurized, the bar itself begins to vibrate along with the tongue, producing beats in the sound.

The tools and equipment used for final tuning are, in principle, no different from those for preliminary tuning, but the tuning method in most cases is auditory, by beat, which still allows for greater accuracy.

Definitions of temperament direction

The difficulty in tuning fifths and fourths in keyboard and reed instruments is determining the direction of temperament: one beat in a fifth can be in the direction of narrowing or widening the interval. In a keyboard instrument, the direction of temperament is established by comparing the direction of rotation of the key and the beat frequency. Establishing the direction of the reed's temperament by restructuring it - by trial and error - is harmful to it, since it leads to an irreversible decrease in its mass and rigidity, which, in turn, worsens the sound qualities of the reed.

Therefore, there is a different method for determining the direction of temperament. The base of the reed is tightly clamped by some metal rib, while the rigidity of the reed increases and its natural frequency increases.

Let's say we check the lower tongue of the interval, the direction of temperament of which we must determine. Pressing the base increases the frequency of the lower sound, and this increase either increases the number of beats in a given interval or decreases it. An increase in the number of beats indicates that the interval was set in the interval narrowing zone, a decrease in the number of beats indicates that the interval was set in the expansion zone.

Setting the tempering area

In multi-voice instruments (modern accordions and button accordions), the tempering area is adjusted using any one pair of reeds to compress and release the bellows. The reeds on other voice strips are covered with a plate with a soft pad (for example, husky). The strips of the tempering area that remain open are called front strips.

After setting the tempering area, all other tuning strips located in the same row are adjusted.

The procedure for adjusting the slats and the features of filing the reeds

The further order of setting the melody and accompaniment bars can be selected as follows:

• reeds of the bass part of the large octave (in octave intervals along the reeds of the melody, taken as drill);
• reeds of the bass part of the small octave (in octave intervals along the reeds of the large octave of the bass);
  counter-octave reeds (in octave intervals along the reeds of the large octave of the bass);
• reeds of the first octave of the accompaniment (in unison with the reeds of the melody);
• reeds of the small octave of the accompaniment (in an octave with the reeds of the first octave of the accompaniment);
• the reeds of the non-string melody bars (in unison with the reeds of the melody strakes).

Filing the reeds during the tuning process requires great care and precision. Haste leads to repeated removal of the metal layer, either at the base or at the top. Repeated filing of the reed worsens its properties: frequency stability decreases when air pressure changes, the threshold for breaking oscillations decreases, the volume decreases, and the timbre deteriorates - it becomes nasal and shallow. The only improvement - lowering the excitation threshold - is not justified against the background of other undesirable changes in sound properties.

There are tongues of a different kind - too hard. Disadvantages of such reeds: increased excitation threshold, the need for high air flow, loud, noisy timbre.

Setting quality control

The quality of the settings must be constantly monitored. Each newly configured row of voice bars must be checked against as many previously configured rows as possible at unison and octave intervals. Mandatory verification of the melody, bass and accompaniment reeds is required.

It is advisable to check the sequence of intervals of the same name and pay attention to the uniformity of changes in the beat frequency in adjacent intervals. If the instrument has a pouring, then its timbre color should also vary evenly from tone to tone.

They finish checking the tuning by checking the correct sound of the chords in the melody and bass, as well as checking the simultaneously sounding chords of the melody and accompaniment.

An important point in checking the tuning: the final control should be carried out at least 24 hours after the last tuning, that is, when the process of relaxation of mechanical stresses is almost completed and the system becomes stable.