Vermona Synthesizer

Eventide Phaser

 

Here is some Schematic for Eventide Phaser i found somewhere ,have not tried to build this however ,a friend built the clock circuit on a breadboard and said it's not working .Anyway to mock up a high freq clock circuit is not so hard ,it would be amazing if the rest of the schematic is correct and working .

Electro Harmonix Sonic Boomer

 I found this schematic and layout many years ago and i even made PCB for this but never built it , so when i tried to find again the layout and schematic on line there was none , or just hard to find so i decided to share it here . This is not my layout ,and i have not built it , but reading the comments elsewhere this is a very nice Kick drum .

BOM : 

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| Electro-Harmonix Sonic Boomer |

|        Component list         |

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Sorted by name

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R1 47

R2 10K

R3 3.3M

R4 3.3M

R5 390K

R6 43K

R7 220k

R8 9.1k ???

R9 1M

R10 68k

R11 47k

R12 47k

R13 1M

R14 100k

R15 10k

R16 10k

C1 0.001

C2 100 EL

C3 10 EL

C4 0.0039

C5 1 EL

C6 4.7 EL

C7 0.0047

C8 0.0047

C9 4.7 EL

C10 0.0047

C11 0.0047

C12 1 EL

P1 1M log

P2 1M lin

P3 1M log dual gang

D1 1N4148

IC1 TL064

SW1 DPDT

X1 Electret microphone

Moog Parametric EQ

 

Many years ago i built the ACX Moog Parametric EQ and it was working fine , so i just saw now the original Moog 3 Band Parametric EQ .This is a striped down version without the switch .

This Moog Parametric Equalizer uses somewhat unusual potentiometers-dual 50k/500R

the drawing board

 

Buchla 106 Mixer updated layout

FA38 Colour 

Hardware Design of Real-Time Musical System

by Sergio Franco 

(excerpts) 

1. Importance of Real-Time in Electronic Music

With the advent of electronic music, the roles of the composer and the performer have been placed in a new perspective. Traditionally, musicians have tended to specialize in either one role or the other, or have tended to play only one of the roles at a time. This has happened mainly because of the considerable difficulty encountered when composing and performing are carried on simultaneously.

When a musician improvises at an instrument, he is essentially composing music in real-time. This means he is thinking and evaluating very quickly a series of possibilities out of which he makes appropriate choices, which in turn lead to the execution of the various mechanical motions necessary to produce the music he wants.

Because of the difficulties encountered in doing all these things at once, musicians have tended to specialize either in the inception/evaluation process (composition) or in the execution process (performance), and have developed the notation of musical scores to communicate among themselves. Thus, the composer need not be principally concerned with the quick thinking and decision making of the improvisational process, but can pursue his inspection of musical possibilities on his own time scale.

What is even more important, to appreciate the effects of his choices and changes, he does not need to try them out on actual instruments because he can rely on his aural imagery, a faculty he has developed through experience either by playing instruments or by listening to others playing them, or both.

In developing his aural imagery, the musician is certainly helped a lot by the fact that he deals with a limited set of instruments whose characteristics extend over known and predictable ranges.

In electronic music the situation is quite different. Because of the new kinds of sounds that electronic instruments are capable of synthesizing, it is very difficult for the musician to develop the kind of musical imagery that may suffice to assist him in composing on his own time scale and away from his instruments. If the composer is to come up with something musically meaningful at all, it is absolutely essential that he actually hear the effects of his choices, his trials, and his alterations as he makes them, so that he can directly evaluate them in the context of the whole composition. In other words, the concept of direct feedback has come to play a dominant role in the electronic music composing process.

Another important change brought about by electronic music involves the relationship between performer and instrument, and is due to the much greater detail in which the performer is required to control the various musical parameters. While in conventional instruments such parameters as timbres, attacks, decays, etc. are, to a large extent, fixed, built-in features, in electronic music they are left to the discretion of the performer, who must therefore specify and control them directly. If this feature allows on the one hand much more freedom of choice and experimentation, on the other it imposes a more demanding control burden upon the performer, and it certainly renders the communication among musicians more complex than with conventional instruments, where the notation of the musical score is usually adequate.

As a result of the above discussion, it should be clear that in electronic music the distinction between composer and performer ceases to exist, partly because the composer needs to try out his musical ideas on the instrument by himself, and partly because of difficulties of communication among different people.

Furthermore, having accepted the notion of direct feedback as an indispensable ingredient of the improvisational process, it is of paramount importance that the composer/performer be allowed to interact with his instrument on the time scale of the music he is improvising, that is, in real-time.

As shown in the block diagram of Figure 28, the realization of the sound distribution system requires a total of 96 audio gates. With a number of this magnitude, the cost per gate plays an important role in the choice of the circuit realization to be adopted.

An audio gate, besides satisfying such obvious requirements as low distortion, high on-to-off transfer ratio, and low control signal feedthrough, must also exhibit specific transient characteristics in order to ensure proper audio switching.

The last requirement is motivated by the fact that when a sound is switched on or off, spurious partials are generated which may alter the tonal character of the sound considerably, as has been discussed in connection with sound enveloping.

As Fourier analysis reveals, the amount of spurious partials accompanying sound switching usually increases with the rate at which sound builds up or decays. Thus, unwanted switching effects can be easily reduced by employing gates with low switching speeds.

From the viewpoint of sound movement control, however, it is desirable to have fast gates so that sounds can be switched around the performance space at arbitrary rates. A compromise between the two conflicting requirements can be determined experimentally.

Analog gates based on solid-state, electro-optical devices like Raysistors or Vactrols usually exhibit predetermined and highly asymmetrical switching characteristics which render these components unsuited to the present application. The cost of these devices at the time of design was also a key factor that contributed to their rejection.

The smoother for the harnonic tone generator has been real-ized with two CA3080 OTArs in the manner i]lustrated in Figure 1p.This circuit realizes a tvo-pole,maximally-f1at, low-pass prograrnrnable fil-ter. Due to the absenceof the voltage-to-current converter and diode compressor, signal conditioning at the OTArs inputs i-s achieved by means of resistor attenuators, as shown. Tire resj-stcr values have been chosen so that the bal-anced outputs from the progranraable mixer can be tied to

 the inputs of the first 0TA directly, without the need for additional ancilfary circuitry. AIso, because of the finite imped.ance presented. by the attenuators, the output from each OTA naust be buffered. by a high input-imped.ance decoupler. This task is performed. by the pair of FET-transistor

source fol-lowers. The voltage-offsets associated vi-th the fol-lowers $o not affect the dc level of the filter because each follover is placed insid.e the feed.back loop of the correspond.ing OTA.

Digital Waveshape Generation

Because of the discretization introduced by the sampling technique, the control of tonal qualities can be exercised only over a limited bandwidth. According to the well-known sampling theorem, the order of the highest harmonic that can still be represented with the sampling process equals half the number of samples contained within one waveshape period.

Thus, if the harmonic generator is to span a wide tonal scope, the number of sampling intervals should be as large as possible. A high sampling density, however, requires a commensurably high frequency for the sequential scan of memory as well as a large memory size to accommodate the samples.

As it has already been pointed out in connection with the relaxation oscillator, the accurate generation of an exponential frequency over a range of three decades becomes more and more difficult as the range is shifted in the direction of higher frequencies.

A compromise has been achieved with the choice of a time resolution of 32 samples per period and an amplitude resolution of 15 levels per sample. Since the tonal bandwidth is determined solely by the number of samples, the amplitude resolution need not be as high as the time resolution.

It should be noted, however, that the presence of the mixer results in an effective increase of the amplitude resolution because it allows for the programming of arbitrary ratios between corresponding samples of the incoming waveshapes.

(Sergio Franco was one of the people that designed the Sal-Mar Construction)

This excerpt is shared for educational and research purposes only, to facilitate discussion and understanding of electronic music history. If you are the copyright holder and object to its publication here, please contact me directly, and I will remove it immediately.

EMU (Universal Active Filter)

 

please contact me if i need to remove this as i don't remember where i found this really elaborate schematic from the Emu Modular 

Bandpass Gyrator Filters or almost an Octave filter

 

Bandpass Gyrator Filters or almost an Octave filter as presented by helge-h here at electro-music forum

i made 4 of these filters as part of my Matrix Mixer ,too bad that more then 6 position switches are really expensive ,but that is the only extra thing you need to expand this filter , i installed the capacitors on the switches as that makes sense to me

GENERAL RADIO 1952 UNIVERSAL FILTER

According to the manual this is a Fourth Order (Four Pole) Chebishev Filters ,that can be set to Low Pass ,Band Pass ,High Pass and Band Reject . Cut off frequencies are adjustable from 4Hz to 60 kHz in four ranges .Find the complete manual here : https://www.ietlabs.com/pdf/Manuals/GR/GR1952%20IM.pdf

 

Ringmodulator Using XR2206. BY OSAMU HOSHUYAMA

 

From the notes on the web site :An amplifier was added so that a guitar or the like can be input. A bias circuit was added so that it becomes just an oscillator when there is no input signal. It also serves as a knob to prevent only the oscillation sound from leaking out when there is no input signal.

I built this on stripboard somewhat modified ,and fitted in old Russian antenna enclosure . 

krohn-hite_3103a

 

krohn-hite_3103a-4_wide-range_10hz-3mhz_band-pass_filter_1981

bruel-kjaer_1613.1_octave_filter_

 

bruel-kjaer_1613.1_octave_filter_

Електронски Музикални Инструменти - Вокодер - Радио бр.9 1984 (А. Смирнов ,В.Калинин ,С. Мулаков)

 

Automatic Phase Box - Everyday Electronics by E.M. Lyndsell (E.E. 1977)

 

voltage scrambler

 This is not an attempt to design a module ..still the ideal diode tutorial from Jim Patchel inspired me for this module ,i was gonna make a panel that featured few of the examples he gives in the tutorial ,and so i even draw this schematic combining 3 simple modules . As in the basic ideal circuit from Patchel's site this module has one input and one break cv input .At the outputs you get 2 different voltages derived from the input voltage and the break voltage input ,these are later fed into 2 voltage controlled glide modules originally designed by Serge ,as these fit very well as submodules cause of their simplicity ,and finally the slewed voltages coming out of the glide submodules are mixed with single cv processor also originally designed by Serge . I find it interesting cause the two upper and lower parts can be inverted with the processor . I am not sure if this would make sense in a modular ,as i have not built it yet ,however i have built a waveshaper based on the ideal diode circuit and that is working fine .

 

 

 

 

 

pcb layout for this module ,made to fit 2 x LCR Vactrols

E.T.S.F. 1979

                                          modules by P. Girard et F. Gaillard ,the whole series available at yusynth archives

WAX

 

Tube Theremin

 Tube Theremin @ http://users.triera.net/zupanbra/elektronke/AM_oscilatorji.html

CMOS chaos

 article link : https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-cds.2018.5544

 

 

 

A Chaotic Circuit for Producing Gaussian Random Numbers

 interesting paper on chaos ,and circuit using 2 x AD633 ,LM311 ,and Opamps ,here is link