Control units use a variety of control sources ¡ a hand-operated stick with three degrees of freedom, a keyboard that uses combinations of notes as well as pressure, a foot controller and even the sound of a voice. Mr. P. Tahourdin was very helpful in developing the engineering basis for the synthesizer design. The original reception of the instruments included debates familiar to today's electronic musician; music.
It is independent of the complexity of the sound produced by the instrument and is independent of the sophistication of the instrument. A musician would like to be able to choose one of a large number of sounds. Monitoring the sound produced by the instrument when it is selected is a very important aspect of sound selection.
With a programmed nusic instrument, it is important that the operator can look at the controls and judge what the sound will be. Usually the musician does not want the range of available sounds I emulated from the instrument.
The second implication is that the musician should be able to
Once the programmed instrument is set. rate of pressing a button to hear the sound as the same. as those that characterize a monitored instrument. setting up a monitored instrument is the same type of operation that. In practice there are many. useful difference between the two types of instruments. Limited degree of selection of sounds by means of physical operations. than a small part of the sounds by which they can be distinguished. ears are available with any setting or arrangement of the monitored instrument. The frequency of an oscillator can be controlled from a keyboard. or from the signal from another oscillator, or a combination of the two. the ability to swap controls greatly increases the number of avai labre sounds.
The control method becomes much more flexible and. the number of sounds available from a given amount of equipment is greatly increased.5. Extensive circuits are necessary to attempt. the synthesis of the sound of a piano, and this equipment could be used to give a large number of sounds which are characteristic. of electronic techniques rather than strings. The scan time would be chosen to match the resolution of the ear and the small computer or microprocessor would operate. the fast Fourier transform on the frequency power density. of computing time would be available and each segment could be. stored on tape or stored d i g i ta I ly.
Each sound segment could be adjusted by the doctor with using the visual display. For the rest of this chapter there is a comparison with. the designed synthesizer with a commercially available synthesizer.
- Radical ly Di fferent Design Approaches
- Vari¡blc tlarnlonic Osciìì;rtor
- D. gives the comp.lete switching diagram of the oscillator
The frequency of tlre oscillator is determined by the rate of charge of the voltage on the capacitor, C of diagram 3.2,8.
- kCI 10 ka
This manual filter consists of a high-pass hall and key filter, and also a low-pass hall and key filter, both of which are of second order. The block diagram of the \^/hite Noise Generator is shown in Diagram 3.5.4 and the circuit diagram is given in Diagram 3.5 and Diagram 3.5.C,. Sound manipulators are characterized by having sign.rl in¡ruLs as ivcìì as signal outputs.
Sound sources and sound manipulators are designed so that each combination produces a distinct type of sound. The number of combinations of these units exceeds the total number of units and in this way sound manipulators expand the variety of sounds available from a given amount of equipment. SM.l is followed by the sound manipulator SM, usually differs from the case where the order of the sound manipulators is reversed and SM,.
This is the best estimate of the number of different types of sound, because using a non-linear sound manipulator means that the order of the sound manipulators is important. Permutations of sound sources and sound manipulators for different ratios of sound sources to sound manipulators.
5 lf combinations of one sound source and one sound manipulator are
The effect of the filter on the sound can be predicted, which allows the musician. The synthesizer filter has high-pass, low-pass, and bandpass outputs, and its transfer characteristics are led for voltage control. A simplified circuit of this second-order filter and a corresponding block diagram are given in diagrams lr.3.n.
The bandpass output is present at the input to the integrator, which has the lowpass output, C(s). These polynomial expressions, giving the poles and zeros of the transfer functions, illustrate that the desired loci of the poles will be obtained. This is equivalent to changing the gains of both the integrators and the results in a Frequency Sheet without a change in the A of the filter.
Analog Multipl iers - Feedthr:ough
Anaìog Multipl iers 0ffset
In this case the determinant of the quadratic equation v s (thc characteristic equation) is zcro. When the poles for system 2 are located together on the real axis, they are at - 2G., I Ît and the zero is at - zc/CZ. Therefore ncc('ss¡ry tr¡ clesiqn.r rlonlltì(:iìr t-('r;istivt: t'lt'ntt'trl wl riclr bo litl The values of the resistors in these segments can be calculated knowing that there will be a voltage drop of .7 V across each. The required changes to the output voltage across each section can then be calculated. The values of the resistors in these segments can be calculated knowing that a voltage drop of 0.7 will occur. The input to the nonlinear resistor should be between 0 and 5 V, and the control voltage range is between -5 and +5 V. Locus of the poles of the low-pass filter when the damping factor is changed, with the. The principle is capable of excellent inertness due to the high switching speeds now available. The first, which uses only three I Ìnear op-amps to achieve four-quadrant multiplication, is novel, according to the author, and suitable for synthesizer use. However, the multiplication principle can be improved, as shown in the EAI 180 analog computer. When the analog gate of the inverter is short-circuited, v* is at reference potential and the circuit is a normal inverting amplifier. The corresponding voltage error on the output is 1mV, and this can be avoided in. This means that the average value of the output shift waveform . is proportional to the value of the input signal ui1. This waveform. is now used to operate an analog inverter which lr.rs the second signal. to be muì type given in the introduction of i ts. A time delay in the switching device does not refer to the sign-to-space ratio, which Ì is determined by the net charge on the capacitor for each cycle. The dominant harmonic depends on the magnitude of the input signal as shown in diagram 4.¡.f. The value of the resistor combination in the collector for each segment can be calculated by knowing the required currents at. The total resistance determines the current to the inverting or non-inverting input of the differential amplifier. Although the transfer function is extremely uneven, the output waveform is found to still have significant components of the fundamental frequency of the input signal. The resistance of the field-effect transistor is extremely large (more than 109 n), while the A divider audio manipulator must provide frequency components that are multiples of the input frequencies. V/when a number of frequency components are present at the input of an intermodulation of a noninary element of frequency components. it happens The control voltage output range can be adjusted. It tracks the sensitivity of voltage change to physical movement. This is provided by the Sound to V:ltage unit. output voltages which are functions of frequency and amplitude. A control voltage manipulator was made to provide the differential. and the integral of the control voltage. This is possible because the keys that determine the frequency of the trumpet work, so combinations are important. Similarly means the average of two voltages. obtained frequency is the geometric mean of the original frequencies. The analogue part of the circuit diagram is given in diagram 5.3.8. the signals 1 of all keys are displayed again. 0 transition This does not apply to keyboards where the control voltage is changed from one discrete voltage. The resistive plate controller is designed to provide intermediate characteristics; both discrete and continuous changes can be obtained at. The paper can be cut to produce different distributions, with thinner sections having the largest possible gradients. Another way to increase the flexibility of the controller is to introduce signal inputs into the Paperr's potential distribution. The sound-to-voltage unit is unique in that it converts controversial voltages from the amplitude and. The basis of the design of the oscillator is given in the circuit in diagram 6.2.A. A comparator' has an output of +V vol ts when the voltage on the non-inverting input (v+¡ is greater than the. The voltage on the inverting input' v-, is connected to the output voltage via a first order ìah circle. Then the output will switch to voìts -V, and the potential at the non-inverting input will simultaneously change due to. The potential divider on the non-inverting input can be replaced by a precision voltage control led inverter as shown in diagram 6.3,C. It remains to obtain a logarithmic relationship between this control voltage and the oscillation frequency.
The basic circuit
