A disc jockey, more commonly abbreviated as DJ, is a person who plays recorded music for an audience. Types of DJs include radio DJs (who host programs on music radio stations), club DJs (who work at a nightclub or music festival), mobile DJs (who are hired to work at public and private events such as weddings, parties, or festivals), and turntablists (who use record players, usually turntables, to manipulate sounds on phonograph records). Originally, the “disc” in “disc jockey” referred to shellac and later vinyl records, but nowadays DJ is used as an all-encompassing term to also describe persons who mix music from other recording media such as cassettes, CDs or digital audio files on a CDJ, controller, or even a laptop.

DJs commonly use audio equipment that can play at least two sources of recorded music simultaneously. This enables them to blend tracks together to create transitions between recordings and develop unique mixes of songs. This can involve aligning the beats of the music sources so their rhythms and tempos do not clash when played together and enable a smooth transition from one song to another.

“DJ” is used as an all-encompassing term to describe someone who mixes recorded music from any source, including vinyl records, cassettes, CDs, or digital audio files stored on USB stick or laptop. DJs typically perform for a live audience in a nightclub or dance club or a TV, radio broadcast audience, or an online radio audience. DJs also create mixes, remixes and tracks that are recorded for later sale and distribution.

The quality of a DJ performance (often called a DJ mix or DJ set) consists of two main features: technical skills, or how well the DJ can operate the equipment and produce smooth transitions between two or more recordings and a playlist; and the ability of a DJ to select the most suitable recordings, also known as “reading the crowd”.

Condenced DJ history from https://en.wikipedia.org/wiki/History_of_DJing

• In 1935, American radio commentator Walter Winchell coined the term “disc jockey”.
• In 1943, radio DJ Jimmy Savile launched the world’s first DJ dance party by playing jazz records. In 1947, he claims to have become the first DJ to use twin turntables for continuous play, and in 1958 became a radio DJ at Radio Luxembourg.
• In the late 1950s, sound systems, a new form of public entertainment, were developed in the ghettos of Kingston, Jamaica. Promoters, who called themselves DJs, threw large parties in the streets that centered on the disc jockey, called the “selector,” who played dance music from large, loud PA systems and bantered over the music with a boastful, rhythmic chanting style called “toasting”.
• In the mid-1960s, nightclubs and discothèques continued to grow in Europe and the United States. Specialized DJ equipment began to appear on the market.
• In 1969, American club DJ Francis Grasso popularized beatmatching at New York’s Sanctuary nightclub.
• In 1973, Jamaican-born DJ Kool Herc, widely regarded as the “father of hip-hop culture,” performed at block parties in his Bronx neighborhood. Turntablism, the art of using turntables not only to play music but to manipulate sound and create original music, began to develop.
• In the mid-1970s, the soul-funk blend of dance pop known as disco took off in the mainstream pop charts in the United States and Europe, causing discothèques to experience a rebirth. Discothèques used the DJ’s selection and mixing of records.
• In 1975, record pools began, providing disc jockeys access to newer music from the industry in an efficient method.
• In 1979, the Sugar Hill Gang released “Rapper’s Delight”, the first hip-hop record to become a hit.
• In 1981, the cable television network MTV was launched, originally devoted to music videos, especially popular rock music. The term “video jockey”, or VJ, was used to describe the fresh-faced youth who introduced the music videos.
• In the early 1980s, NYC disco DJ Larry Levan, known for his electric mixes, gained a cult following. Around the same time, the disco-influenced electronic style of dance music called house music emerged in Chicago.
• During the mid-1980s, techno music emerged from the Detroit club scene.
• During the early 1990s, the rave scene built on the acid house scene. The rave scene changed dance music, the image of DJs, and the nature of promoting.
• In 1992, the lossy compression scheme MPEG-1 Layer-3, popularly known as MP3, later revolutionized the digital music domain.
• In 1998, the first MP3 digital audio player was released, the Eiger Labs MPMan F10.
• In 1999, Shawn Fanning released Napster, the first of the massively popular peer-to-peer file sharing systems.
• 2000s: At the start of the new century, the introduction of advances in technology. Pioneer DJ came to be the digital standard. Audio and Video Mixers were developed. In the 2000s, EDM found its way into pop music and became somewhat mainstream.
• 2010s: DJing continues to move into the mainstream. SoundCloud, a streaming platform intended for independent artists to distribute their music, is created and launched. Ibiza is a huge inspiration for 2010′s DJs in general. The 2010s began what the 2020s would know as the Electronic Dance Music (EDM) movement.

DJs have changed their equipment as new technologies are introduced. The earliest DJs in pop music, in 1970s discos, used record turntables, vinyl records and audio consoles. In the 1970s, DJs would have to lug heavy direct-drive turntables and crates of records to clubs and shows. In the 1980s, many DJs transitioned to compact cassettes. In the 1990s and 2000s, many DJs switched to using digital audio such as CDs and MP3 files.

Nowadays in big events DJs often play pre-mixed music and act like they could would be doing mixing. In DJ culture, miming refers to the practice of DJ’s pantomiming the actions of live-mixing a set on stage while a pre-recorded mix plays over the sound system. Miming mixing in a live performance is considered to be controversial within DJ culture (miming is increasingly used as a technique by celebrity model DJs who may lack real mixing skills). Miming is commonly used in big events that have huge light shows that are carefully synced with the music.

DJ mixers

DJs often use specialized DJ mixers, small audio mixers with crossfader and cue functions to blend or transition from one song to another. DJ mixers are small audio mixing consoles specialized for DJing. Most DJ mixers have only several audio inputs and can drive DJ headphones for listening audio.

A DJ mixer is a type of audio mixing console used by disc jockeys (DJs) to control and manipulate multiple audio signals. Some DJs use the mixer to make seamless transitions from one song to another when they are playing records at a dance club. Hip hop DJs and turntablists use the DJ mixer to play record players like a musical instrument and create new sounds. DJs in the disco, house music, electronic dance music and other dance-oriented genres use the mixer to make smooth transitions between different sound recordings as they are playing. The sources are typically record turntables, compact cassettes, CDJs, or DJ software on a laptop.

The DJ mixer crossfader was originally developed as a control for implementing smooth fades from one program source to another. Fading between two independent sources was first accomplished by DJs using two separate controls, often rotary controls. “Rosie” is the first known electronic DJ mixer, circa 1965. The new control was called a crossfader and has achieved wide use and acceptance. Original control was a constant-power crossfader taper. It was soon clear that one crossfader response curve was not suitable for all applications. Defined standards did not exist for the tapers and some mixers had somewhat adjustable slope. The crossfaders failed when used a lot and the solution for easy crossfader repairs was to design mixers with field serviceable crossfaders. To improve performance and extend service life, audio was removed from the crossfader control and processed in a voltage-controlled amplifier (VCA) or some other voltage/current controlled element. This practice greatly reduced travel noise and extended service life, but the performance of affordable VCAs was limited.

DJs use equipment that enables them to play multiple sources of recorded music and mix them to create seamless transitions and unique arrangements of songs. An important tool for DJs is the specialized DJ mixer, a small audio mixer with a crossfader and cue functions. The crossfader enables the DJ to blend or transition from one song to another. The cue knobs or switches allow the DJ to “listen” to a source of recorded music in headphones before playing it for the live club or broadcast audience.

Very many modern DJ mixers now include a beat counter which analyzes the tempo of an incoming sound source and displays its tempo in beats per minute (BPM), which may assist with beatmatching analog sound sources.

Turntables

Turntablists, who are often called DJs (or “deejays”), generally prefer direct-drive turntables over belt-driven or other types, because the belt can be stretched or damaged by “scratching” and other turntable manipulation such as slowing down a record, whereas a direct drive turntable can be stopped, slowed down, or spun backwards without damaging the electric motor.

Turntablists, also called battle DJs, use turntables and DJ mixer to manipulate recorded sounds to produce new music. In essence, they use DJ equipment as a musical instrument. Perhaps the best-known turntablist technique is scratching.

In 1971, Matsushita released the Technics SL-1100. Due to its strong motor, durability, and fidelity, it was adopted by early hip hop artists. The most influential turntable was the Technics SL-1200, which was developed in 1971 by a team led by Shuichi Obata at Matsushita, which then released it onto the market in 1972.

Technics SL-1200 is a series of direct-drive turntables originally manufactured from October 1972 until 2010, and resumed in 2016, by Matsushita Electric (now Panasonic Corporation) under the brand name of Technics. S means “Stereo”, L means “Player”.

Nowadays Vinyl is more popular than ever. A record doesn’t convey a momentary, digital impression of the music, but preserves it for all time as a physical groove cut into vinyl. You can touch it, collect it, and pass it along, and it’s simply fun to play! But you’ll need a turntable, and there’s a wide variety available for any application. Club DJ turntable techniques include beatmatching, phrasing and slip-cueing to preserve energy on a dance floor.

CD players for DJs

A CD player is an electronic device that plays audio compact discs, which are a digital optical disc data storage format. CD players were first sold to consumers in 1982.

Denon made many CD players suitable for DJs. A DJ CD player adds more controls for the playback compared to the normal consumer CD players. Typical features of the DJ CD players are playback speed control, robust construction and fast operation. Denon DD CD players with two CD slots was a very popular starting in the 1990′s (like DN-2000F). In 1992 Denon launched the DN-2000F dual CD player. This was the first standard CD player for Mobile DJ’s and Clubs. Many pro audio companies such as Gemini, Denon DJ, Numark, Stanton, and Vestax produced DJ quality CD players.

Demo of Denon DN-2000F MKII, DJ Double CD Player
https://www.youtube.com/watch?v=yyUVHtfhT80

Denon DJ player quickly became the industry standard and was widely adopted in most clubs and mobile DJs throughout the 90s up until 2004 when Pioneer made an impact with the CDJ-1000. Pioneer DJ CDJs have since become widely regarded as the industry standard.

CDJ

As compact discs became popular media for publishing music, specialized high-quality CD players known as CDJs were developed for DJs. CDJs can take the place of turntables or be used together with turntables. Many CDJs can now play digital music files from USB flash drives or SD cards in addition to CDs.

A CDJ is a specialized digital music player for DJing. Originally designed to play music from compact discs, many CDJs can play digital music files stored on USB flash drives or SD cards. In typical use, at least two CDJs are plugged into a DJ mixer. CDJs have jog wheels and pitch faders that allow manipulation of the digital music similar to a vinyl record on a DJ turntable. Many have additional features such as loops and beat analysis that are not present on turntables.

Pioneer CDJ players became the industry standard. In September 2014, with an estimated DJ market share of 60%.

Laptop DJ software

As technological advances made it practical to store large collections of digital music files on a laptop computer, DJ software was developed so DJs could use a laptop as a source of music instead of transporting CDs or vinyl records to gigs. Unlike most music player software designed for regular consumers, DJ software can play at least two audio files simultaneously, display the waveforms of the files on screen and enable the DJ to listen to either source. Phrasing and beatmatching, which can be partially or completely automated by using DJ software that performs automatic synchronization of sound recordings, a feature commonly labelled “sync”.

The waveforms allow the DJ to see what is coming next in the music and how the playback of different files is aligned. Many software can analyze music files to identify their tempo and where the beats are. The analyzed information can be used by the DJ to help manually beatmatch like with vinyl records or the software can automatically synchronize the beats. In some software digital signal processing algorithms in software allow DJs to adjust the tempo of recordings independently of their pitch (and musical key, a feature known as “keylock”). Additionally, DJ software can store cue points, set loops, and apply effects.

DJ software requires specialized hardware in addition to a computer to get best results. The consumer-grade, regular sound card integrated into most computer motherboards can only output two channels (one stereo pair). However, DJs typically need to be able to output at least four channels (two stereo pairs). DJ software can be used in conjunction with a hardware DJ mixer or be used instead of a hardware mixer.

To get best results, a suitable DJ controller hardware is needed. When mixing on a computer, DJs often use a DJ controller device that mimics the layout of two turntables plus a DJ mixer to control the software rather than the computer keyboard & touchpad on a laptop, or the touchscreen on a tablet computer or smartphone. Many DJ controllers have an integrated sound card with 4 output channels (2 stereo pairs) that allow the DJ to use headphones to preview music before playing it on the main output. DJ controllers are made by many companies and they often sold with a DJ software.

There are special vinyl records that can be used with DJ software to play digital music files with DJ software as if they were pressed onto vinyl, allowing turntablism techniques to be used with digital files. Those vinyls are pressed with a special signal, referred to as “timecode”, to control DJ software. The DJ software interprets changes in the playback speed, direction, and position of the timecode signal and manipulates the digital files.

While DJing with a computer has been an industry standard for many years, DJing using smart devices, such as iOS and Android-based systems, is fast becoming a popular option. Many DJ software have been written to run on smartphones and tablets in addition to laptops. There is a great selection of controllers for DJing with smartphones and tablets out there.

Best freeware plug-ins: Five of the best free software and apps for DJs
You can kickstart your DJ career without splashing out on high-end software. Here’s our round-up of the best freeware DJ tools.
https://musictech.com/guides/buyers-guide/best-freeware-dj-tools-plugins-software/
The best free software for DJs at a glance:
Atomix VirtualDJ
Serato DJ Lite
Mixxx
Mixvibes CrossDJ Free
UltraMixer

Gear links:

https://en.wikipedia.org/wiki/CDJ

https://www.thomann.de/blog/en/turntables-which-is-right-for-me/

https://crossfadr.com/2011/10/12/generic-midi-devices-as-diy-dj-controllers/

https://www.popsci.com/gear/best-dj-controllers/#amp_ct=1674339130772&amp_tf=L%C3%A4hde%3A%20%251%24s&aoh=16743389403607&referrer=https%3A%2F%2Fwww.google.com&ampshare=https%3A%2F%2Fwww.popsci.com%2Fgear%2Fbest-dj-controllers%2F

https://www.soundi.fi/uutiset/blam-mashupien-kuningas-iskee-jalleen-whamin-ja-black-sabbathin-yhdistelma-sai-geezer-butlerinkin-hykertelemaan/#Echobox=1673939260

Breaking Down Hardwell’s New DJing Style in 2022

https://m.youtube.com/watch?v=jWmETRllGEs

https://en.wikipedia.org/wiki/Pioneer_DJ

How to DJ with just a laptop! – The best beginner DJ software?

https://m.youtube.com/watch?v=MEh7LTu4OJk

Evolution of the DJ Crossfader

https://www.ranecommercial.com/kb_article.php?article=2122

https://www.digitaldjtips.com/2020/06/legally-download-free-dj-music/

https://en.wikipedia.org/wiki/CDJ

https://www.juno.co.uk/junodaily/2021/08/05/brand-focus-denon-dj/

https://mixxx.org/

Free and open source DJ software for Windows, macOS, and Linux
Mixxx integrates the tools DJs need to perform creative live mixes with digital music files.
Whether you are a new DJ with just a laptop or an experienced turntablist, Mixxx can support your style and techniques of mixing.

https://you.dj/free-dj-software

https://cueup.io/blog/best-free-dj-software

A TRIP THROUGH DJ BOOTHS: 1976 – 2016
The evolution of DJ technology

https://mixmag.net/feature/a-trip-through-dj-booths-1976-2016

HISTORY REVISION: THE ART OF THE DISCO EDIT
The controversial practice still shaping modern dancefloors

https://mixmag.net/feature/the-art-of-the-disco-edit

DJing with the SYNC Button: What’s All The Fuss About?

https://beatmatchguru.com/djing-with-the-sync-button-whats-all-the-fuss-about/

You may of seen that little button on your DJ equipment called ‘SYNC’. Now if you’re a more established DJ the you’ll know what is does I’m sure. If you’re read up on the DJ scene then you’ll also know that there’s positive and negative chat around the topic of using SYNC.

When Do DJs Use Sync?

https://beatmatchguru.com/djing-with-the-sync-button-whats-all-the-fuss-about/

https://homedjstudio.com/sync-button/

https://wearecrossfader.co.uk/blog/djs-using-sync-button/

Free DJ software for learning
You’ll pick up DJing quickly with Serato DJ Lite. It’s easy to learn and keeps things simple while you’re starting out.
Built on Serato DJ Pro technology, you’ll find it reliable and intuitive.

https://serato.com/dj/lite

Air DJ Contest – This guy is pretty sensational

https://www.dailymotion.com/video/x7q526a

https://www.instructables.com/DIY-USB-DJ-Controller/

Homemade DJ MIDI Controller

https://www.youtube.com/watch?v=x-1_TEETVOA

DIY MIDI DJ controller mixer with arduino and 3d printed parts

https://www.youtube.com/watch?v=Z1Fl6ekkipE

Building the Traktorino – The Arduino MIDI controller for DJs

https://www.youtube.com/watch?v=6XTUEFfQe20

#1 Playing the Traktorino – the Arduino Uno shield for Traktor

https://www.youtube.com/watch?v=lY6cjM9_2Vg

https://www.native-instruments.com/en/catalog/traktor/

https://www.native-instruments.com/en/products/traktor/dj-software/traktor-pro-3/

https://en.wikipedia.org/wiki/Turntablism

DJing With MIDI Controllers – zZounds Music Blog

https://blog.zzounds.com/2020/11/03/djing-with-midi-controllers/

Launchpad || DIY or Buy || Keyboard Matrix & MIDI Tutorial

https://www.youtube.com/watch?v=wyKStRyez5Y

All you need to know about djing with smartphones & Tablets

https://www.reloop.com/djing-with-smartphones-and-tablets

How to Practice DJing Without Equipment – A Starter’s Guide

https://startingtodj.com/dj-without-equipment/

How to DJ – Modern DJ equipment explained and demonstrated by DJBigRedAZ

https://m.youtube.com/watch?v=2tHUc1ULuyY

How to DJ with a Laptop in 5 MINUTES

https://www.youtube.com/watch?v=a9vk-aJcpIk

How to DJ on your Laptop with Serato DJ Lite (FREE SOFTWARE)

https://www.youtube.com/watch?v=R2oNGZ5479g

A Beginner’s Guide to DJing (How to DJ for Complete Beginners)

https://www.youtube.com/watch?v=O-pdaMnOJBQ

Which is the BEST DJ software (for you)?

https://www.youtube.com/watch?v=LaSJkj4_j2w

All-in-one DJ Gear vs Laptops/Controllers – Which Is Best?

https://www.youtube.com/watch?v=TVS9tkyZvyc

All-in-one DJ gear vs laptops/controllers – Which is best? Phil Morse looks at the pros and cons of both in this week’s Tuesday Tips Live show..

For all the techs wining about DJs who play all the way in the reds..
Pioneer just released this mixer with the stagehand app. Take control of the DJ.

https://youtu.be/05AgTCmWDt8

Tutorials:

how to dj
LEARN HOW TO DJ IN 8 STEPSLEARN HOW TO DJ IN 8 STEPS
It goes without saying that anyone who feels a calling to be a DJ should definitely know their music well. In addition to this, however, you need to have a feel for the audience and be able to entertain the crowd. After all, the DJ sets the tone of the party!
https://www.thomann.de/blog/en/learn-how-to-dj-in-8-steps/

https://en.wikipedia.org/wiki/Turntablism

https://www.thomann.de/blog/en/learn-how-to-dj-in-8-steps/

https://blog.pioneerdj.com/pioneer-dj-history/it-was-all-a-dream-the-brief-history-of-audiovisual-djing/

https://www.thomann.de/blog/en/essential-gear-for-dj-beginners/

https://www.musiikkiluvat.fi/perustietoa/dj-lisenssi-ja-musiikin-tallentaminen-11-yleisinta-kysymysta/

https://cdm.link/2018/12/build-your-own-scratch-dj-controller/

https://www.mspot.com/why-is-dj-equipment-so-expensive/

Evolution of the DJ Crossfader

https://www.ranecommercial.com/kb_article.php?article=2122

History of DJing

https://en.wikipedia.org/wiki/History_of_DJing

https://en.wikipedia.org/wiki/Turntablism

Turntables: Which Is Right For Me?
https://www.thomann.de/blog/en/turntables-which-is-right-for-me/

https://en.wikipedia.org/wiki/Technics_SL-1200

https://en.wikipedia.org/wiki/Disc_jockey

Fun:

Star wars dj set
https://youtu.be/ekgpZag6xyQ

here is a killer bass drop
When Will The Bass Drop? (ft. Lil Jon)
https://youtu.be/XCawU6BE8P8

Fake DJs Compilation

https://www.youtube.com/watch?v=9b-VvAkH8xE

The Snow DJ ! WITH TRACKLIST! ALL SONGS!

https://m.youtube.com/watch?v=asBkswg4q4I

I DJ’d At A Top London Night Club & Only Played Hold Music

https://m.youtube.com/watch?v=sVUiGGPWO2w

DJ Gets Exposed after Video Surfaces of Him Playing without Any Equipment
Read More: DJ Gets Exposed after Video Surfaces of Him Playing with No Gear

https://1079ishot.com/dj-exposed-playing-without-equipment/?utm_source=tsmclip&utm_medium=referral

Disco LED
It is a simple tutorial on how to create disco lights.
https://www.hackster.io/MightyProjects/disco-led-b261d5
The project is about the disco lights. Just upload the code to the arduino and enjoy the lights in a dark room.

Disco Lights With Arduino
https://www.instructables.com/Disco-Lights-With-Arduino/

Disco Lights
https://mehackit.org/en/courses/electronics_projects/05-projects/04-disco_lights/
Build disco lights that flash to the beat of the music. The sound sensor in the Maker Kit can track music, and at the same time, we’ll learn how to flash five leds independently with Arduino.

I need some help making a disco ball
https://forum.arduino.cc/t/i-need-some-help-making-a-disco-ball/874123
This project is triying to recreate the melody “Take on me” using two piezos and flash some LEDs. There is the code and discussion on that.

Arduino 101 with Blinking Disco LED
https://www.ashishvishwakarma.com/arduino-101-disco-led/
This is a beginner level Arduino DIY. Tweak the Arduino blinking LED example with a Tri-color LED, and made it as Disco LED.

RGB Disco Light
https://www.instructables.com/RGB-Disco-Light/
This project will show you how to create a rainbow disco light with just some wires, code, and an RGB LED module.

Arduino LED Chaser|| Sequential LED Blinker || Chaser LED
https://www.hackster.io/helloanimesh390/arduino-led-chaser-sequential-led-blinker-chaser-led-ca266f

PROJECT 4: DISCO STROBE LIGHT
https://www.oreilly.com/library/view/arduino-project-handbook/9781457198861/xhtml/ch04.xhtml
Turning the potentiometer up or down changes the speed of the flashing lights, creating a strobe effect. You can use red and blue LEDs for a flashing police light effect.

WS2812 based circuits blog post
https://www.epanorama.net/newepa/2016/06/19/ws2812-addressable-leds-test/
WS2812 is a intelligent control LED light source that the control circuit and RGB chip are integrated in a package of 5050. WS2812b LED strips are very popular among the maker community because of their versatility and ease-of-use.

WS2812b LEDs
https://learn.illuminations.mit.edu/chapter/ws2812b
In order to make MIT Illuminations-style lights at home, we need to scale up from programmatically controlling one LED to a lot at once! WS2812b LED strips are very popular among the maker community because of their versatility and ease-of-use.

How To Control WS2812B Individually Addressable LEDs using Arduino
https://www.youtube.com/watch?v=UhYu0k2woRM

ARDUINO DMX512 CONTROLLER
https://www.youtube.com/watch?v=4PjBBBQB2m4
Using the DMXSimple Arduino library, you can get to get two American DJ Micro Wash RGBW PAR can lights running, controlling them with manual commands from the serial monitor or automatic scenes from the sketch.

NEOPIXEL DMX Controller for a WS2812B LED Strip Using Arduino Uno
https://www.youtube.com/watch?v=RZ_UWYBOj8M
How to use Arduino as a DMX controller and receiver to control commercial DMX fixtures as well as your own projects. This uses the Arduino to send and receive custom hard coded data with the DMX protocol, not meant to receive other standard controller data.

How to Make DMX512 Fixture Using Arduino to Control the Stepper Motor | How to Build DMX512 Fixture
https://www.youtube.com/watch?v=RtvbEccsefk
This is a project demonstrating how to make DMX512 Fixture Using Arduino to Control the Stepper Motor. We have controlled the Stepper motor position angle using the value on the DMX512 channel. In this fixture we can change the Channel number addressing using the simple DIP switches.

Disco lights DIY
https://www.epanorama.net/newepa/2024/04/21/disco-lights-diy/

More videos:
https://youtu.be/bNWzbIw8Mfs?si=yLPNU8CA0xi9ZH9A
https://youtu.be/nB3DT5NU-vA?si=FZ-lMXN-SFCLwcu7
https://youtu.be/G-zCNkNp4RY?si=UwvrA9n2QXHOl7UV
https://youtu.be/2uLxyBaii70?si=X_m9g1kVHIkDSq8B
https://youtu.be/82dXy_CqCeg?si=rd8J-Vt-ohI0xGtw

I did build some disco lights in 1990′s. Nowadays you can buy many disco lights more cheaply than you could buy the components. DIY is makes often sense only as a learning experience or if you need something really special that is not available ready made (and can cost time and money to make). Here is my small light control board that consists of two 300W light dimmers.

One device I used a lot was a color organ circuit to control your light colors with sound frequencies, lows, mids and highs on different colors. Microphone, pre amp, frequency filters and a switch to flash different color lights based on the music frequency. I used an older version (slightly different case) of Velleman K8017 kit that controlled a set of 230V 150W halogen floodlights with color filters. If you are building light organs nowadays, it might be a good idea to have a LED color organ circuit powered with safer low voltage.

For single channel light dimming I built aDC-OHJATTU HIMMENNIN K8064. When I needed more channels, I built Four channel dimmer rack based on Velleman K2634 Quad Triac Card Kit. I used the same Velleman K2634 Quad Triac Card Kit to build a four channel light switch box that could be controlled with 5V or 10V on/off control signals.

Here are links to some circuits I have used:

https://www.epanorama.net/index2.php?section=circuits&index=light

Archive of disco Light circuits plans from “Canada’s largest manufacturer of disco lighting controllers in the 70s.”
https://www.epanorama.net/schematicsforfree/Lights/index.php

DMX allows you to control lights further though, like a full stage system
https://www.epanorama.net/newepa/2019/10/20/enttec-open-dmx-diy/

DMX 512 control board DMX 192 repair
https://www.epanorama.net/newepa/2021/03/15/dmx-512-control-board-dmx-192-repair/

Enttec Open DMX DIY
https://www.epanorama.net/newepa/2019/10/20/enttec-open-dmx-diy/

Four channel DMX-512 light dimmer
https://www.epanorama.net/newepa/2016/06/13/four-channel-dmx-512-light-dimmer/

DMX-512 decoder for RGB LED
https://www.epanorama.net/newepa/2017/03/07/dmx-512-decoder-for-rgb-led/

DMX-512 led light teardown
https://www.epanorama.net/newepa/2019/10/16/dmx-512-led-light-teardown/

LED DMX-512 lamp teardown
https://www.epanorama.net/newepa/2019/10/21/led-dmx-512-lamp-teardown/

Amplifier rack
https://www.epanorama.net/newepa/2021/06/19/pa-amplifier-rack/

2023 Halloween Hackfest: Musical Jack-o-Lanterns Harmonize For Halloween
https://hackaday.com/2023/10/12/2023-halloween-hackfest-musical-jack-o-lanterns-harmonize-for-halloween/
Put on a show in the yard with some musical, light-up jack-o-lanterns you find build instructions at
https://hackaday.io/project/193086-musical-jack-o-lanterns

2023 Halloween Hackfest: Candy Basket Sees You Coming
https://hackaday.com/2023/10/14/2023-halloween-hackfest-candy-basket-sees-you-coming/

2023 HALLOWEEN HACKFEST: A SPOOKY MUSCLE-BRAIN INTERFACE
https://hackaday.com/2023/10/16/2023-halloween-hackfest-a-spooky-muscle-brain-interface/

BONE-SHAKING HAUNTED MIRROR USES STABLE DIFFUSION
https://hackaday.com/2023/10/16/bone-shaking-haunted-mirror-uses-stable-diffusion/
Spookifying Haunted Mirror build using Stable Diffusion
https://tim.cexx.org/?p=1628

Links for more:
https://www.epanorama.net/newepa/?s=halloween
https://hackaday.com/blog/?s=halloween

Let’s talk CES 2022 trends
Another year defined by the pandemic
https://techcrunch.com/2021/12/31/lets-talk-ces-2022-trends/

You can keep up with Techcrunch #CES2022 coverage here
https://techcrunch.com/tag/ces-2022/?tpcc=tcplusfacebook

The Verge CES 2022 News
https://www.theverge.com/ces

CES 2022′s live reveals are here: How to watch this week’s announcements
Many CES exhibitors are taking their reveals online instead of attending live from Las Vegas.
https://www.cnet.com/tech/mobile/ces-2022-live-reveals-are-here-how-to-watch-this-weeks-announcements/
CNET will livestream many of these events on CNET’s main YouTube channel and the CNET Highlights channel.

AV can make or break your event. Great AV and your event will run seamlessly.

On the other hand, event AV mistakes can leave your guests wishing they never came and can make your event the talk of the town for all the wrong reasons. A bad AV mistake like projectors that stop working during your keynote bringing the presentation to a halt, will make attendees immediately regret coming.

Anything crucial to your event needs to have a backup in place and ready to go should equipment fail.

Ultimately, the key to avoiding these common event AV mistakes comes down to organization and clear communication.

Windows error song. DJ prank

Armin van Buuren – This Is A Test (Arkham Knights Remix)

This converts NEMA mains connector to 1/4″ plug. Offers a nice set of possibilities for unexpected show disasters like electrocution or over kilowatt of constant 60 Hz bass line without an amplifier.

It seems that some company really tried yo push this potentially extremely dangerous product to market – and fortunately failed in it. You can read more about it at https://controlgeek.net/blog/2008/5/29/j-con-an-oldie-but-goodie.html where those pictures are from.

The danger of this product is that an user could very easily by mistake use this to connect speakers and exposed connector to mains power with disasterous results.

This has also fueled some later joke pictures like this.

WARNING: Connecting audio cable to mains power is dangerous and should not be done in real life. This kind of cables can be lethal if connected to mains power and someone touches them.

One somewhat related to note is that Banana Plugs are Banned in Europe for speaker connections. They are not legal for use in europe because they can be plugged into a wall outlet!! European electric wall plugs are round, and the same size of a standard banana plug. HiFi amplifiers and speakers that have binding post typically has cap on top of the binding post to prevent banana plug use.

In most European countries, the standard mains power receptacle will physically accept single 4 mm banana plug and even US-style “double banana” plugs (the standard US pin spacing of 3/4 inch (19.05 mm) is close enough to the mains plug spacing of about 19 mm, and the pin diameter is also compatible), leading to a risk of electrical shock.

Did you know that figure 8 power cable plug (IEC 60320 type C plug also known as IEC C7) fits in xlr connector? Even the pin size is exactly right to get good connection for feeding mains voltage between pins 1 and 2. Which is a really bad idea an potentially very dangerous.

A friend called from a big computer festival Assembly 1999 that was starting. It was one of the biggest this type of event in Europe with thousands of people coming with computers. Some of my friends was running big screen and video streaming for the event.

They had all the stuff rented and set up for the event by the AV contractor. Everything worked flawlessly on the previous day. But on the first day the audio and video system started picking up lots of noise. The audio signal had mains humming in it, and video signals had “humming bars” on them. As more computers get powered up on the hall, the worse the noise becomes. We are not talking about few computers, there was over two thousand computers on the hall.

Same event 2010

I walked in to the even with my tool-set. Solving the audio problems involved sorting out the lines that picked most noise. Most of the audio connections were analogue (both balanced and unbalanced) and most video connections used composite video interface. I walked in to the event with necessary tools. A combination of audio signal isolation transformers and “ground lift” on some balanced audio lines made situation OK.

Video signals were a tougher problem. There were some very long video line runs from the main video mixer to different locations (projectors for big screen, smaller screen etc..). Those long video lines seemed to have lots of noise in them. I measured form 100 mA to 1 ampere mains AC current on coaxial cable shields on the cables with most humming bars! Disconnecting some of those longest lines made the video system to work noise free, but what to do because we can’t live without connections to video projectors.

The main program on the event was starting on the next day, so this problem needs to be solved so that everything works flawlessly or at least “well enough” by tomorrow. I know I would needed some type of video signal isolation devices for those problematic video lines, but our equipment supplier did not have them. It was already quite late night, so it was impossible to try other sources.

Fortunately I had one prototype of video “humbugging” transformer with me. It was a common mode choke built by winding thin 75 ohm coaxial cable over a suitable toroid transformer core. This device reduces the amount of current flowing on coaxial cable shield and reduces the noise pickup. I built the device based on some old documentation (someone sent me old document from BBC on hum bugging transformers). I tested this DIY “humbugging” transformer on one of the video lines, and it worked very well. The amount of noise on that video line was reduced to point that it could no longer be detected on the big screen.

The problem is that there were also other lines that seemed to need the same kind of treatment. I went to home lab, trying to gather whatever parts I could find to build more such devices. I ended up building three more on the night from the part I could find – I even managed to find nice plastic cases for them. Next morning I came with my brand new “humbugging transformers” to the event. They worked and saved the show next day. What I made looked pretty much like this inside (this is a later made version that uses the same box).

In the end the video equipment provider that rented most of the video gear for the event end up buying my boxes after the event at decent price. I ended later making some more for this company. I ended up making more on then when needed for some video companies. Quite often when I first rented few of them to solve an emergency, they wanted to buy them for themselves.

They have performed very well on many video systems to solve ground loop problems. There are passive hum suppressor transformers that will very effectively remove the hum from the video signal, but do not affect the video signal otherwise. Those special transformers act like a common mode coils, which stop the annoying ground loop currents on the shield of the coaxial cable, but provide a straight path for the signal inside the cable. This type of device is capable of passing the signals from DC to tens of MHz without problems. The hum suppressor transformer both reduces the current flowing on the cable shield and compensated the voltage differences that would otherwise be between cable ends and eventually get to the signal.

You can find more information on my ground loop noise reducing boxes at
https://www.epanorama.net/blog/2009/09/06/build-humbugging-transformer/ and https://www.epanorama.net/blog/2009/09/15/build-video-isolator/ and https://www.epanorama.net/blog/2010/08/12/audio-isolation-transformers/.

I ended doing more audio and video tricks to keep this event running,