Creating video feedback loops without a mixer

Work in progress

Video feedback loops are one of the most interesting effects you can generate with analogue video devices. However, they can be quite pricy - you generally need some sort of video mixer, and those can go for more than 100€ on eBay.
In this page I'd like to explore other methods of creating feedback loops with much more inexpensive devices, without requring a mixer (even if it is useful to have for more complicated effects).

All of these methods can also be combined together (as well as with a video mixer, if you do have one) to form more and more interesting effects.

Using DVD recorders

A potentially underappreciated method of obtaining a feedback loop is to use a DVD recorder (or a DVR); they can be obtained for not that much more than a conventional DVD player. After connecting the output of the recorder to one of its inputs, a loop is formed - however, I strongly recommend obtaining some sort of video processor box (or even more than one) to place in the loop, to have some sort of control over the image formed.

The recorder has to digitise the video input, process it, and then convert it back to composite - this adds a bit of input lag (as well as a slight loss of quality), which is very useful for creating interesting effects. This can be increased further by adding more than one recorder in the loop.

One advantage of using DVD recorders for this is that they can also be reused for playing back video in a larger setup, or for recording footage (as they offer better quality than the "Easycap" capture devices, at about the same price). They can also be stacked easily on top of each other and on other equipment, and almost always have their own built-in power supply.