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Summing Amplifier – Mastering Electronics Design. Arduino is a popular family of open source microcontroller boards. Hobbyists, students and engineers all over the world use this platform to quickly design and prototype a microcontroller driven circuit. One of its interfaces with the analog world is the ADC. Since these boards are mostly designed around an ATMEL ATmega32 or ATmega168 microcontroller, the ADC has 8 inputs and 10-bit resolution, making it suitable for many applications. From time to time I receive a message through my Contact page with the question, how to interface a sensor, or an outside circuit with the Arduino ADC? In most cases the answer is an interface between a bipolar circuit and the Arduino board. As the bipolar circuit output varies from some negative to a positive level, the Arduino ADC cannot measure this signal directly, because the ADC inputs can only be between 0V and the reference voltage.

Read moreMeasure a Bipolar Signal with an Arduino Board. Help me choose a differential amplifier. I am not a certified electronics engineer, so I bow to those who are. Having said that, I don't think there is anything nasty about this. These article explains how an inverting operational amplifier circuit works. As you can probably see. The circuit you are looking for is the first, basic inverting amplifier.

Essentially, the gain is the ratio of voltages across the input and output. The golden rules of Op Amp behaviour with feedback (from "The Art of Electronics") are:1 The output attempts to do whatever is necessary to make the voltage difference between the two inputs (+ and -) zero.2. So if the + input goes to 1V, and the ratio of the two resistors is 1:2, then the output will go to 2V. Negative feedback is a way to set the gain. How do I connect differential input amp to Arduino DAC? How to Control Feedback in a Sound System. By Shure Notes Editors. Contributors: John Chevalier, Bill Gibson, Frank Gilbert, June Millington, Dan Murphy “John had a semi-acoustic Gibson guitar.

It had a pickup on it so it could be amplified. We were just about to walk away and listen to a take when John leaned his guitar against the amp. He really should have turned the electric off. It was only on a tiny bit and John just leaned it against the amp when it went ‘Nnnnnwahhhh!’ – Paul McCartney (Source: Many Years From Now, Barry Mile) It’s pretty much common knowledge among students of pop music that The Beatles’ 1964 recording of “I Feel Fine” was one of the first known examples of feedback as a recording effect, even though The Kinks and The Who reportedly (and intentionally) used it in live performances.

In this post, we’ll cover some of the fundamentals – what causes feedback and how to avoid it – along with tips from some of our favorite audio pros. What is acoustic feedback? What causes it Pro Tip #1 Pro Tip #2 Ringing Out. Lives in the Balance and Dr. Greene's approach. Legacy products. Sensorlab The STEIM SensorLab was one of the first small, general purpose, sensor to midi interfaces for the prototyping of musical instruments and interactive control systems. Whether the computer is a central element in an artists work or simply a tool bridging a technological gap, the need for real world input and output is essential. The SensorLab paved the way for later developments in what is now called Physical Computing, such as the ever-popular AVR-based Arduino boards. Unfortunately, the Sensorlab is no longer for sale. JunXionboard The junXionboard is STEIM’s second generation sensor interface.

BigEye BigEye© was one of the earliest commercially available pieces of software to perform real-time tracking of video events. Typically achievable frame rates range from 12 frames per second PPC 7100/66 to (the maximum) 25 on an PPC 8500. BigEye is FREE. MidiJoy MidiJoy is a prehistoric version of junXion for OS 8.x and 9.x. The Lick Machine System requirements The Lick Machine is FREE. Starr Labs | High Tech MIDI Devices. Music Magic USA Accordion and Midi CyberStore - Your source for the Roland FR-7x Accordion. MIDI 9 - Add MIDI to Any Keyboard Instrument. Highly Liquid: DIY MIDI Electronics. DIY MIDI controllers using PIC microcontrollers and Basic Stamps | Ross Bencina. Introduction By combining a PIC microcontroller or Basic Stamp II with a few passive components it is not difficult to construct your own knob box, trigger box, or other MIDI input device. A knowledge of electronics may be required for interfacing to some sensors. Both the Stamp and PIC provide an economical (under US$100) entry point into the world of alternative MIDI controllers.

This page was created to provide a starting point for people interested in building their own MIDI control devices using Microchip PIC microcontrollers or Parallax Basic Stamps. Basic Stamps and PICs A Basic Stamp consists of a tiny circuit board on which is soldered a PIC CPU, a timing crystal, and some EEPROM memory for program storage. Microchip Technology Inc. manufacture a large range of PIC microcontrollers. See Peter H. Interfacing to MIDI For both the Basic Stamp II and medium range PIC chips, MIDI (i.e. serial) output is implemented in software by manipulating the state of a data pin. MIDI output Other. Isomorphic keyboard. Fig. 1: The Wicki isomorphic keyboard note-layout, invented by Kaspar Wicki in 1896. Examples[edit] Helmholtz's 1863 book On the Sensations of Tone gave several possible layouts. Practical isomorphic keyboards were developed by Bosanquet (1875), Janko (1882), Wicki (1896), Fokker (1951), Erv Wilson (1975–present), Wesley (2001) and Antonio Fernández (2009).[1] Accordions have been built since the 19th century using various isomorphic keyboards, typically with dimensions of semitones and tones.

The keyboards of Bosanquet and Erv Wilson are also known as generalized keyboards. The keyboard of Antonio Fernández is also known as Transclado. Invariance[edit] Isomorphic keyboards expose, through their geometry, two invariant properties of music theory: Theory[edit] Benefits[edit] Two primary benefits are claimed by the inventors and enthusiasts of isomorphic keyboards: Comparisons[edit] See also[edit] References[edit] External links[edit] Software[edit] CONTROLLER ZONE. Terpstra Keyboard | Get One! Funding a production run for the Second Generation Terpstra Keyboard Prototypes was a community project, meaning the Terpstra is not a commercially available product, and can’t be purchased anywhere.

With other words, YOU CAN NOT GET ONE right now. But you can join the pre-order list and as soon as there will be at least twenty orders in place, we’ll run another batch. If commercially available, the keyboard would cost more than $10K USD. We estimate the per unit price for an eventual future production run roughly between 1/3 and 1/4 of the commercial price. Just send us an email using the address contact @ this website, stating how interested you are (want one and have the money, need to save for it, etc.) and whether you’d like to receive the extremely rare updates about this next funding campaign. We don’t know if we’ll be able to answer all letters, but feel free to join our Terpstra Keyboard Facebook Group and connect with us and other Terpstra enthusiasts.

Microtonality, Tunings and Modes. There is still a lot of good music waiting to be written in C major. — Arnold Schönberg One of the most liberating aspects about using a computer to compose music is that non-traditional “frequency space” can be explored in different ways without having to address the limitations of physical instruments or human performers. This sort of experimentation may involve working with raw, untempered Hertz values, just harmonic ratios, microtonal inflections, or “alternate” tuning systems, which we define very broadly to mean any tuning system other than the standard 12-tone equal tempered scale.

But working with an expanded frequency space using MIDI synthesizers will quickly expose a strong bias of MIDI towards the popular music tradition and the Western tonal system in general. MIDI and Microtonal Tuning There are two basic methods for producing microtonal sound on a MIDI synthesizer. Channel Tuning Note by note tuning Equal division tuning Channel Tuning in Common Music Interaction 15-1. Cents. CONTROLLER ZONE. The Sound Reinforcement Handbook: Gary Davis, Ralph Jones: 0073999009644: Books. Church Soundguy: Effective Microphone Strategies That Produce Great Results With Church Choirs. What mics work well for the choir? Where should the mics go, and how many are needed in each situation? Suggestions that point you in the right direction by Bruce Bartlett In house-of-worship sound system installations, one of the biggest challenges is miking the choir.

We want to achieve a good balance, a natural sound, and high gain before feedback. Another goal is to make sure that the microphones are invisible! What mics work well for the choir? Mics for Choir The most popular type of choir mic is a small hanging mic. Choir mics are condenser types with a cardioid or supercardioid polar pattern. Condenser mics can be made much smaller than dynamics of equivalent bass response. An example of a miniature choir mic. Choir mics are built in three parts: mic head, cable, and power module. At the far end of the cable is a power module with an XLR connector or a terminal block. Also, the module equalizes the mic signal and converts it to low-Z balanced. Figure 1: Typical choir mic placement 1. Shure Microflex Low Profile Boundary Microphone - Black; Omnidirectional w/LED - MX395B/O-LED.

Shure Microflex Low Profile Boundary Microphone - Black; Omnidirectional w/LED - MX395B/O-LED The Microflex Low Profile Boundary microphone is an ideal table microphone when minimal presence is of high priority. Perfect for meeting rooms, these microphones deliver exceptional sound pickup while barely being noticed. Choose from a selection of colors and pickup patterns for customized table installations. Cartridge polar pattern indicated by model number suffix(C = Cardioid, BI = Bidirectional, O= Omnidirectional): FeaturesOnly 1.25 inch (3.8 cm) in diameterCardioid, omni and bidirectional polar patternsWide dynamic range and smooth frequency responseAvailable in black, white and aluminumBi-color status indicator available with -LED modelsLogic input for remote LED controlCommShield Technology.

Audio-Technica PRO 44 - microphone. Shure MX393/O Microflex Black Omnidirectional Condenser Boundary Microphone - - Acoustical Measurements for the Rest of Us. How to make acoustical measurements without a Ph.D. As Lord Kelvin said, “To measure is to know for sure…maybe. The acoustical behavior of the rooms we produce music in is often baffling. To make it worse, acoustical treatments are regularly shrouded in hypespeak (as in “Our Soundsucker® Wall Panels will remove all time smear and clarify the reverberation of all acoustic instruments.”).

Often we suspect that something might be wrong with our room, but we don’t know how to find out. When we consider the cost of measurement equipment that acousticians use and the steep learning curve needed to use it, we can easily see why room acoustics remain baffling. They aren’t easy to understand, they’re expensive to measure and hard to learn about, and they’re tangential to what we really want to do—which is to make really cool recordings.

Happily, it’s possible to make some measurements on your own with some fairly basic equipment. There’s another benefit to all of this. Rooms vs. frequency Whew! Software to analyze and equalize frequency response of entire sound system? Sweeping the Frequencies for Precise EQing - Tuts+ Music & Audio Tutorial. If I there's one plug-in that's the audio equivalent to a Swiss Army knife, it would have to be the EQ plug-in. From subtle corrections to drastic sound design changes, you can use an EQ plug-in for an almost infinite list of tasks. In this tutorial, I will show you one such technique, called Sweeping the Frequencies, that can give you surgical-like precision when EQing and notch filtering a sound source to better fit in your mix. When using an EQ—which is short for Equalizer—you are essentially given control over a sound source’s volume.

But instead of having an overall global affect, like when using the master gain on a channel strip, you can turn the volume up or down on specific frequency bands independent of the other frequencies. You can quite literally filter which frequency bands you want to turn up or down and affect only the ones you want, which is where the term filter comes from. Tip: Make sure your volume is at a safe level. This audio example is a bit extreme. Exploring the Boundaries – A Close Look at an Invisible Microphone | B&H Photo Video Audio. By Ken Hamberg Boundary microphones as a class are often overlooked – literally. Flat-lying and inconspicuous by design, they lack the glamorous appearance and prestige of their conventional large-diaphragm counterparts, which are often photographed in the company of the world's best-known and culturally iconic singers, entertainers and public servants.

Boundary microphones in fact enjoy a ubiquitous if highly discreet presence in recording studios, concert halls, installations, public address systems, conference and meeting rooms, and houses of worship. Regardless of their humble, vaguely bug-like appearance, boundary microphones represent some of the most versatile, functional, and reliable mics ever made, and we'd like to take a brief look at how they work and what they can do for you. On Reflection Born and bred in the U.S.A., boundary microphones are a relatively recent innovation invented in 1978 by talented audio consultant Ed Long and veteran recording engineer Ron Wickersham. Presence (amplification) In an amplifier, a presence control boosts the upper mid-range frequencies to make the sounds of voices and instruments with similar tonal ranges seem more "present".[1] On television production studio's sound desk, there can be several presence controls, for several different, switchable, frequencies.[2] There is a limit to the flexibility of such controls, and they are sometimes insufficient.

If the degree of mis-match between microphones is great, simply increasing presence is not enough, and instead a sound engineer will use a graphic equalizer, sometimes several, each connected to an individual sound channel.[3] Presence controls can also be found on electric guitar amplifiers. The first presence control on a Fender amplifier, for example, appeared in 1954 on the Twin. In 1955 it appeared on the 1/15 Pro-Amp, the 3/10 Bandmaster, the 2/10 Super,[4] and the 4/10 Bassman.[5] The original Fender presence control acted upon the amplifier's negative-feedback loop. Optimum Stereo Signal Recording with the Jecklin Disk. Josephson Engineering Photo of a Jecklin-type disk made by MB Electronics in the mid 1980s.

The central plate is about 8 mm (a little less than 3/8") thick, covered on both sides with 8 mm thick foam. The foam is probably too thin; there is still too much high frequency energy reflected from the disk. The Jecklin-type disks supplied by Josephson Engineering since about 1995 use 25 mm foam. Jecklin is shown in his book with a disk of the same diameter but covered with lamb’s fleece. The NHK (Japanese national broadcasting) version of the disk extends this covering to include the circumference of the disk as well. The following text is reproduced from Jürg Jecklin’s 1980's paper Microfon Aufnahme Systeme. A: The OSS technique (OSS = optimum stereo signal) The idea of a new microphone arrangement is the result of the dissatisfaction about the sound of usual music recordings, which has made itself felt during the course of approximately 4000 recording sessions. I. II. B. I. II. III. IV. C. Multimedia Audio Course - Microphones and miking techniques - Stereo miking techniques: near coincident microphones - Sound engineering - Audiosonica.

Multimedia Audio Course - Microphones and miking techniques - Stereo miking techniques: near coincident microphones - Sound engineering - Audiosonica.