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CMOS Synthesizers - Beavis Audio Research

CMOS Synthesizers - Beavis Audio Research
Chip Basics For our experiments, we'll use a couple basic chips: 40106 Hex Inverting Schmitt Trigger: This chip contains 6 individual Schmitt triggers. 4040 Binary Counter/Divider: This simple logic chip takes an input square wave and generates oscillations at 8 outputs with a frequency related to the input frequency. 4051 Eight Channel Analog Multiplexor/Demultiplexor: The voltage status of the three address pins A, B and C determines which of the eight channels presents its voltage to the common connection pin. Note: All schematics on this site use the following notation for potentiometer tapers: A = Logarithmic, B = Linear Let's Build Something Fun In our first experiment with a flexible tone generator, let's look at the Heterodyne Space Explorer. More Fun: Heterodyne Peyote Space Explorer This piece is a conglomeration of various things: three independent oscillators, a complex waveform generator, a white noise circuit and a mixer. Using Your Effects! References and Further Reading Related:  Synth Hackingcircuitstheory and patches

Send and Receive MIDI with Arduino : Receive MIDI Messages with Arduino Most Arduino MIDI projects send MIDI messages out, but you can also use the Arduino to receive MIDI data. Here are some ideas: an Arduino synthesizer that uses MIDI messages to construct audio waveforms a device which uses MIDI to trigger mechanical events, like the ringing of different sized bells a MIDI to control voltage(CV) device- communication between MIDI and analog synthesizers Parts List: MIDI connector Digikey CP-2350-ND 220Ohm 1/4watt resistor Digikey CF14JT220RCT-ND 1N4148 diode Digikey1N4148-TAPCT-ND 10kOhm 1/4watt resistor Digikey CF14JT10K0CT-ND 470 Ohm 1/4watt resistor Digikey CF14JT470RCT-ND (I used 2x220 instead) 6N138 optocoupler Digikey 751-1263-5-ND The hardware setup is slightly more complicated for receiving MIDI than it is for sending. The following code receives these messages, reads them, and stores them appropriately. To make sure that everything is working properly, try the code below.

fun with sea moss (or, basic digital sound devices) by Sebastian Tomczak. Please email for blah-blahing Please note that the construction of a square wave oscillator using a hex inverter integrated circuit and then using it to control a digital binary counter integrated circuit is taken from the excellent reference: pp 111-139. Collins, Nicolas 2006, Handmade Electronic Music: The Art of Hardware Hacking, TF-ROUTL. Index Digital Logic All of the schematics presented here in the 'Sound Devices' section operate on the premise of digital logic - that is, a reliance on two individual states used to represent information. Binary Numbers Multiple states can be encoded as information when considering a set of 1s and 0s. 1s and 0s and Electricity Electricity is able to represent the idea of a 1 and a 0 quite easily. back to top Logic Chips There are three types of integrated circuits used in these mini-projects. The 40106 is a hex inverter. The 4040 is a binary counter / divider. Sound Devices Basic Equipment List Oscillator

Synth Secrets, Part 16: From Sample & Hold To Sample-rate Converters (1) Gordon Reid introduces the synthesis modules that allow you to create a number of commonly used 'random' effects, and their close relatives -- analogue sequencers. This is the 16th article in a 63-part series. Read all parts. You might think that after more than a year's worth of articles about oscillators, filters, amplifiers, LFOs, contour generators, external signal processors, and heaven knows what else, we would have exhausted the modules that make up an analogue synthesizer. Not a bit of it! This month, we're going to start with a common synth component, the Sample and Hold module, and consider its use with a few less common ones. Not All Samples Are Digital Given that it's not necessary for generating any conventional imitative sounds, the Sample and Hold (S&H) module is remarkably common. Imagine, if you will, that a standard synthesizer signal is presented to the input on the left of the diagram. Clock Generators udio oscillators and LFOs. in red). Introducing Sequencers

MIDI Library, For Communication With Musical Instruments MIDI, by Francois Best, allows you to control and receive data from musical instruments. MIDI 2.6 and 3.2 and later support all Teensy models. Hardware Requirements MIDI uses the UART to communicate with standard MIDI devices at 31250 baud. This is completely separate from, and can be used together with USB MIDI. You can use Serial.print() to observe what your program is doing, while using MIDI, or USB MIDI. MIDI connects using the UART's transmit and receive pins. MIDI input requires an optically isolated input. Teensy 3.0: Use two 47 ohm resistors on MIDI OUT, with the pin 4 resistor to +3.3 volts. When connecting the signals, be sure to connect to the correct pins. Basic Usage MIDI.begin(MIDI_CHANNEL_OMNI); Initialize the MIDI library. Transmit basic MIDI messages.; Receive a MIDI message. MIDI.getType(); Returns the type of message received. MIDI.getData1();MIDI.getData2(); These return the 2 data bytes of the received MIDI message. Example Output Program Example Input Program Details

Simple Circuit Diagram | Free Simple Circuit Diagram DIY @ Detachment 3 Laboratories - ph33r t3h m4g1k sm0k3 The Master Synthesizer Book List r1.1 This is intended as a one-stop reference for analog and digital synthesizer design, covering both the specifics of design and the general fields that encompass them. Wherever possible, I have used books from Dover Publications because of their technical depth, illustrious authors, and budget-minded pricing. Embarking on a self-taught engineering path can be expensive, though not as costly as a formal education in Electrical Engineering or Computer Science. For every book outlined here, do not underestimate the power of used bookstores and clearing houses like Also look for previous editions of these books which can be purchased at a great discount from the shiny-new cover price. If you have any additional references that should be added to this list, by all means contact me! One final note. The List: Analog Tomes: Digital Tomes:

Interesting WTPA2 MIDI Opto Repair - Narrat1ve Nerd Camp So, while I was testing these pre-assembled units, I found one that had intermittent MIDI functionality. The symptoms were these: Mess with MIDI keyboard, MIDI works normally. Wait 20 seconds. The first NOTE_ON or NOTE_OFF after that fails. "Aha, a bug", I thought. However, all other assembled WTPA2 units worked fine. I probed the input to the UART pin on the MCU coming from the optocoupler. So I resoldered a bunch of stuff. Rising edges on the MIDI signal to the opto were wussy; I stiffened the value of the pull up on the opto's output. Eventually I decided to swap the optocoupler (a 6N138). So, if you get intermittent MIDI and you've checked anything else, swap the opto. (NOTE -- I was using some old crusty reference schematic from the MIDI spec, but according to this: The 6N138 doesn't really need a super stiff pull up. Thought I'd share.

Juergen Haible "Living VCOs " back to JH. homepage I already have a lot of different VCOs, from the ultra precise MOTM-300 to the lush, but not so well-tracking VCOs of my EMS-Synthi clone. Features Drift and Noise and all that stuff Every few years there seems to be a heated debate how "stable" a good-sounding VCO should be, or shouldn't be. want to get rid of them, or add them externally, or deliberately keep them in your VCO. Audio Demo 1 13.5 MByte mp3 (First dry: just VCOs thru VCA. CS-80-Style PWM Like the Yamaha CS-80, the Living VCOs have a limited pulse width. Bill of Materials Component Overlay (component values) Component Overlay (reference designators) Schematics Schematics, Page 1 Schematics, Page 2 Schematics, Page 3 Schematics, Page 4 Wiring diagrams What I provide is just the PCB and some ideas how to hook it up. Wiring, Option 1 Wiring, Option 2 Wiring, Option 3 Calibration Calibration is quite similar to what you have on other VCOs.S - Scale. For more information, please contact Copyright J.

Analog Modular Synthesis undefined Copyright 1997 by André C. Stordeur All rights reserved. Upon numerous requests,this is a sample of a complete tutorial about the technique of Analog Modular Synthesis by Voltage Control. It is also an ideal refresher course for emusic professionals hopelessly bored by the lack of real time controls in digital FM Synthesis and MIDI Sampling and who want to have fun again... This Course is divided into 10 Chapters, each Chapter covers what you need to know about Electro-Acoustic Theory : it also contains a lot of examples and practical patching ideas. There is also a Chapter devoted to 'Hybrid' solutions : it analyzes in-depth what interfaces are necessary to control Analog Synthesizers from a computer using MIDI or control all MIDI modulations from one or several Analog synthesizers. Experiment and enjoy...

Shruthi – DIY resources | Mutable Instruments This section contains all the information allowing you to build your own Shruthi or hack its firmware. The Shruthi contains two section: a digital section (“control board” or “digital board”), containing the display, main microcontroller, switches and pots ; and an analog section (“filter board”) hosting the VCF, VCA, input mixer and the output stage. Several variants of the filter board are available to provide a broad range of sounds. Control board Filter board This filter board is part of the standard kit: SMR4 mkII, a solid, Roland-ish, 4-pole filter. These filter boards are no longer in production: LP2+Delay, the combination of a MS-20 LPF and a low-fi digital delay. 4-Pole Mission, a 4-pole multimode filter inspired by the Oberheim Xpander. Mutable Instruments has stopped publishing any information regarding the use of “vintage” SSM/CEM/IR integrated circuits. Special editions To celebrate the launch of new filter boards, limited edition series of kits have been sold. Enclosure