DE2053906A1 - Electronic musical instrument in which all tones are derived from a main generator - Google Patents

Description

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PHI. 4457 Ta / PP

Dipl.-Ing. F.-J. TfUiCESA

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,., ...-.,: N.Y. Philips' Gloeilampenfabrieken

File Ne. PHN-4437
Registration dated October 30, 1970

"Electronic musical instrument in which all · Tom« τοη · 1η · α main generator be derived."

The invention relates to an electronic "Muaikinatrum" nt, in which all tones from a main generator by means of at least one Plate circle «·· can be derived, with the outputs of the divider of this Divider circle or these divider circles are connected to a matrix.

Such musical instruments are known in which the tones an octave can all be derived from a main generator, while the octaves below are derived from those mentioned above by means of a two-parter twelve tones can be derived

For the imitation of certain musical instruments, x.E. Pianos and Elavisimbeln, is this ratio of the frequencies of the octave tones not quite right

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Because of the invention, this part is avoided, that the frequencies of the tone run according to a Railsbaok curve. Daduroh is achieved that the sound of such musical instruments unites It has a more natural character.

Another feature of an embodiment of the invention a divider circle is provided for each tone, with the output the matrix “at least one divider connected to one input” can, so that the desired frequency appears at the output of the divider circuit.

According to a further embodiment of the invention is only

* a single divider circle is provided and "the matrix bit is provided with a separate output for each tone ·

With this design, plate circles are saved, where in general there is a 2 * -divider behind each output of the matrix is arranged to the difference in the distance «wipe the pulses borrow.

According to a weathered embodiment of a musical instrument according to the invention, in which only one frequency is taken at a time the frequency can be set by switching the matrix. This fc version is particularly good for melody instruments or tuners suitable.

Bs is obvious that switching the matrix either at the entrances or exits and also at the entrances and exits this matrix can be done.

D The expression "matrix" used above has no structure ▼ on Sohaltern, of which one or more inputs with a or connected to several outlets and which can be of any type For example, they can be formed by mechanical, electronic switches, etc. will.

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In a further development of a musical instrument according to the invention, which is t in particular constructed as a Stimager *, is a filter, preferably a bandpass filter _f rorgesehen, the circuit in an amplifier may be arranged and at least the ObertSne the suppressed to tune the tone of the su stiemenden musical instruments , while the output signal of the filter or the amplifier circuit is fed to a first input of a frequency difference detector, a signal bit of the frequency of the tuner being applied to a wide input of this detector to compare the two frequencies. This is particularly favorable because otherwise a simultaneous occurrence of the pure harmonics of the tone of the tuner tea and the ObertSne of the tone of the instrument to be tuned, e.g. a clarifier, could impair the vocal channel. The undesired effect τοη by-products with a frequency falling below the frequency of the tone to be tuned can be partially eliminated by designing the filter as a band filter.

The output signal can be sent directly to the filter or, if the filter is arranged in the feedback line, to an amplifier circuit is to be taken from the output of the amplifier circuit. The deviation τοη the correct frequency of the correct tone can be read "

In a favorable embodiment of a musical instrument according to the invention the Irenz frequency of the filter's is simultaneously with the output frequency of the tuner switched. This allows the both functions can be switched with a single button.

In the case of a different shape of a musical instrument, naoh According to the invention, the filter is an active linear filter, τοη at least one of the frequency-determining elements close to an equal measure

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trix is trained and switched.

A linear filter is to be understood as meaning a filter whose Durohlassfrequens is linear with the value of at least one of the frequency-determining members changes.

Daduroh uses a special simple and fillers loht arrangement while the switches can be the same.

The invention is explained below with reference to the accompanying drawing explained in more detail. It owns

Fig. 1 shows the mean deviation with respect to the equal tempering as a function of the pitch.
* Flg. 2 is a block diagram of a piano, and

Fig. 3 «in an embodiment of a digital divider from the Clarify after Flg. 2,

Fig. 4 * in another embodiment of a clarification, and Fig. 5 shows a tuning device, 6 shows an exemplary embodiment of a double-T filter, and FIG Fig. 7 «la circuit diagram of a frequency difference detector.

Fig. 1 shows the mean deviation in besug on the same parts Tempering as a function of the pitch of a tuner fc make clarifier tuned to the ear, the so-called Reilsbaok curve. These Deviation is mainly due to the fact that the frequencies the overtones of a clearing page looks exactly the same as goose Yielfaohen the Frequens de · Gunrdton ··, but are about · higher. Vie out the Railsbaok curve is ersiohtlioh, is the mean deviation of the lowest and highest notes in the middle register for example 35 oent. This deviation determines the sound character a · clarification · with. The Bailsbaok-Abweiohuag is not constant, but rather rarlates little for every instrument and every tuner.

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Fig. 2 shows blocksohematisoh "in clarifier according to the invention, in which O denotes the main oscillator, which is connected to the inputs τοη dividing circles D. _t Dp. ·. D is connected »where each circle of plates belongs to a certain key of the piano and η is equal to the number of τοη keys. The output of each divider circle is connected to a percussion position P ₁ , P ₂ ... P _n , each Ferkussionssostellung τοη of the associated test is actuated and causes the characteristic of a string instrument attack and the subsequent decay of the sound. The Τδηβ read through by the percussion postures are amplified in the usual way not described in detail and converted into acoustic oscillations.The divider circles consist of digital dividers, the outputs of which can be connected to a matrix in the manner desired for the associated tone, as shown in Fig. 5 is. In this case the matrix consists of a number of diodes which together form an AND gate, the output signal of which is possibly fed back via a pulse sucker I su reset inputs of the digital divider The number of digital dividers is dependent on the desired frequency of the lowest tone In the present case For example, a number of 19 digital two-part B is sufficient.

For the tone a ¹¹¹ with a frequency of 1768.2 Hs, s _v B. the outputs of B ₂ , B ,, B ₅ , B ₁₀ and B .. are connected to the inputs of the AND gate. It is evident that for this tone the dividing circle only needs to consist of 13 two-parters. Each divider produces a specific tone.

In the embodiment according to FIG. 4, the main ossillator O is connected to a divider circuit D ₁ , which consists of the digital _{dividers B 1} , B ₂ , B -... B _a , the number of dividers m nozzle determining the desired accuracy of the frequencies becomes «ad the outcome of every two-part

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■ it «in ·« input of a matrix gate boundaries, which in this case also be a ana η Ünd-Oattern H ₁ , Mg · ..> _Β , where η again represents the number of tones, and where the output every · And Gate with a 2 divider C ₄ , C ₀ ... bsw. C Tcrbunden iat, who for his part is old of a piglet posture P., Po ···? « ^{Ttr1> tuld} · ¹¹ iat, which percussion postures are again carried out τοη the associated acts. The interconnection of the 2 ⁿ divisors is necessary in this case because the distance between the pulses occurring at the outputs of the AND gates is not constant, which irregularity τοη these 2 ⁿ divisors is reduced to a smaller size.

With the examples described above, a solution for the construction of a polyphonic musical instrument was obtained. Ea is einleuohtend that it is sufficient for a melody instrument to form the matrix the more durable, ao that the generator of FIG. 2, only a einsigen divider circuit and daa instrument NaOH Fig. 4 vox szmtag SUCHE Artists AZ a single ⁿ 2 dividers.

A melody instrument of this type can be used, for example, as a Stlangerit for tuning τοη stringed instruments, such as piano, KlaTizimbeln etc., can be used.

With such a tuner it is desirable to use the tones with a frequency exceeding the string to be tuned or sifting frequency below, because this »it the ObertSnen dea The tuning devices are not in harmony and complicate the tuning process would.

Fig. 3 shows such a tuner, in which 0 again denotes the main oscillator and a dividing circle with two-divisors B ₁ -B ₁ - with a matrix that can be maintained to produce the terso-sounding tones is seen. In this case transistor «

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2053905

T ₁ ... T ₁ Q uses the emitter-collector junctions of which are connected in legs with the diodes of the AND gates. With this tuner, the notes lying within an octave are struck with the aid of a 1-octave piano K and the octave levels are switched over with their corrections for the Railsbaok deviation by a button BK.

_{With the device concerned, relays R 1} - R ₁₂ are switched at the same time as switching dir Τδηβ and the octaves, whose output contacts switch capacitors C) which form part of a linear filter, which in this case consists of a double-T filter with resistors and capacitors, which is installed in the feedback line of an amplifier T ₁ , the input of which the signal ζ · Β · originating from the string to be tuned is fed via a magnetic pick-up F. By nature, any band filter, such as a double T filter with resistors and inductors, can be used. The output of the amplifier V ₁ is connected to an input of a frequency difference detector F, the second input of which is the frequency of the tuner which originates from the output of the TJnd gate, possibly via a second amplifier V ₂ . A signal then occurs at the output of this frequency difference detector which directly indicates the frequency deviation from the correct pitch.

The double-T filter described is even more detailed in FIG and it should be evident that the resistors can also be made switchable instead of the capacitors. Instead of the relay matrix can of course also have the same electronic matrix as for the switchover the frequency of the tuner can be used, whereby a clear arrangement can be obtained.

The expression ^{M frequency difference detector n} is to be understood here in well-known circuit arrangements that both

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the frequency difference as well as the phase between the two Specify signals.

For example, Fig. 7 shows such a detector.

The tone of the string to be tuned is fed to the input a of this circuit arrangement, while the input b is fed to the signal from the tuner. These inputs are each connected to an input of an acoustically stable multivibrator FF ₁ or FF ₂ at the outputs of which pulses appear with the same width, but whose phase difference changes with the phase difference between the two input signals a and b.
■ The impulses of the monostable multiribrator EF ₁ become one

supplied to the first input of a coincidence circuit C, while the pulses of the monostable multi-vibrator FF »are suggested to a second input of this state of affairs. At the output of the coincidence circuit C, which can consist of an AND gate, pulses emerge, the width of which changes over time, during the pulses of the monostable multivibrators FF. and FF ₂ open at the same time. At the end of the coincidence interval, a sawtooth oscillator Z is put into operation. The two input signals a and b are also fed to two inputs of a phase detector F. The supply line from the input a to the phase detector can be _{interrupted by a switch S 1} , which is opened during a half cycle of the difference frequency of the two input signals when the sawtooth voltage reaches a certain value, so that a signal appears at the output of the phase detector whose sign corresponds to the sign of the frequency difference of the input signals. A pointer instrument V connected to the output of this phase detector, the setting of which is in the middle of the scale, beats to the beat of the differential frequency on the side that corresponds to the sign

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Frequency difference corresponds to

When the switch S. is closed, the difference in frequency of the two input signals occurs at the output of the phase detector F ^, so that the pointer of the pointer instrument V connected to this detector moves back and forth at the difference frequency to both sides of the socket setting.

The output signals of the unostable multiribrators FF ₁ . and FF »» .B. Each integrated via a low-pass filter and the signals received can be fed to the inputs of a differential amplifier, at the output of which a voltage occurs which is a hate for the frequency difference and its torques.

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Claims (7)

- 10 - PHI.4437 FATBlNSPRESCHEt My electronic ·· muskin instrument, in which all · Τδηβ τοη «ines Main generator can be derived by means of at least one divider circuit, where the output of the divisors of this divider circle or these divider circles ait are connected to a matrix, daduroh marked that the The frequencies of the tones follow a raileback curve * 2. Electronic musical instrument according to claim 1, characterized by that a divider circuit is provided for each tone, the output of the matrix bit being connected to an input of at least one divider can be, so that the desired frequency occurs at the output of the divider circuit. 3 Electronic musical instrument naoh claim 1, characterized in that that a single divider circuit is provided, while the matrix kit is provided with a separate output for each tone. 4 · Electronic musical instrument similar to any of the foregoing Claims in which only one frequency can be taken at a time, daduroh characterized in that the frequency can be set by switching the matrix. 5. Electronic musical instrument, in particular a tuner, naoh ψ claim 4t, characterized in that a filter is preferably a band filter which can be arranged in an amplifier circuit and which suppresses at least the overtone of the tone to be tuned of the musical instrument to be tuned, while the output signal of the The filter or the amplifier circuit is fed to a first input of a frequency difference detector »whereby a signal with the frequency of the tuning device is applied to a second input of this detector to compare the two frequencies. 6. Electronic musical instrument according to Claim 5, daduroh marked, that the cutoff frequency of the filter is equal to the 109822/1180 - 11 - PHK.4457 Output frequency of the tuner is switched " 7. Electronic mocha instrument according to claim 6, characterized in that that the filter is in an active linear filter ron that at least one of the frequency-determining members after an equal Matrix is formed and is switched. 109822/1180