Audio and Video

PA amplifier rack

Building a sound system is often a highly personal process, from deciding what to get, to assembling and using it. Here is my PA system I built in 1990′s and used for some mobile DJing. The need for measurements were that it should fit easily to a normal size car with everything else that is

Antenna isolator teardown

A ground loop in your AV system caused by antenna connection or TV cable is very common if you have your computer connected to the same system. This type of ground loop problem can be solved by using suitable isolator between your AV system and the antenna cable. Antenna isolator is very convient way to

VGA as remote camera cable

I have designed many years a VGA cable based video camera cable which could hande video in two directions (from camera to mixer and return video to cameraman), a two-way voice connection (ClearCom type) and 12V power to the camera. All the signals run along an equally long (tens of meters) VGA cable. These were

Dirty video mixing

After the mid 90s boom in popularity glitch has become a critical part of contemporary popular esthetics. How to make Analog Video Glitches | Circuit Bending video discusses how to make unique analog “glitch” textures for your next video: Karl Klomp‘s Dirty Video Mixer is one of the best known and wide used simple circuits

Video balun circuits

Traditionally analogue video transmission is done using 75 ohm coaxial cables. Those video signals are not directly compatible with nowadays more widely used twisted pair wiring (CAT5, CAT6 etc..), which means you just can’t wire the signals directly form video output to a twisted pair wire. The main problems in connecting 75 ohms video source

USB cameras on Android 11 fix

Almost a year ago I wrote that USB cameras connected to Android 10 device do not work. This issue stopped me from using my USB endoscope. I tried different applications and nothing seemed to help. The Android version was updated to 11, but the problem seemed to stay. Not the problem has been solved. I

Ethernet over XLR wiring

I have written about running audio signals over CAT 5/6/7 wires normally designed to carry Ethernet traffic. But is is possible to run Ethernet over audio cabling terminated with XLR connectors? Gearspace discussion at topic “Ethernet over XLR – Can I do this ???” had following question: We recently moved into an old recording studio

Friday Fun: Speaker to mains power disaster adapters

This is an old recipe for a disaster from 1990′s. 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