VGS-FB

Video Synth / Feedback generator add-on for the VGS-35

The VGS-FB is a device meant as an add-on to a previous build of mine, the VGS35 built in September, 2019. The VGS35 utilizes a VGA-to-Composite analog video signal converter, while this one utilizes a Composite-to-VGA converter. It’s main purposes is to feed the signal from the VGS35 back into itself, and it exposes controls for Red, Green, Blue, adds an LFO which is easily assignable to the RGB channels, and it keeps all original functionality by extending the menu buttons to the top panel. Utilizing this device in conjunction with the VGS35 allows it to act as a standalone video synthesizer.

With the easy controls for pulsing and dialing in the RGB mix on this device, and the image shift controls on the VGS35, it’s got a lot of direct access to everything you need to create and play with simple video feedback loops!

Output

Output (Glitched with the VGS-35)

Reference

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The LFO here is a little iffy - this is also a very old design meant for audio devices and it’s got limited abilities here. You might consider testing other circuits here, or pushing the output of the LFO through a vactrol or opto-coupler first rather than sending the point labelled C directly to the colors. Experiment.

The base for this device is a no-name Composite-To-VGA video signal converter from Amazon. There are a ton like it and I imagine many of them are similar if not identical, though the specific one that I used came from a seller called “HDSUNWSTD.”

Portions of this add-on were inspired by LoFi Future, who has done similar builds in fully self-contained units. I had been thinking of adding onto the VGS-35 with something like this when I came across his FB-01. This provided me with confidence to move forward, and his website also provided extremely helpful information regarding methods of mixing the RGB channels & what pot values were needed. Before this I was making feedback loops with my PC, so I was extremely happy to find a solution that made it a self-contained machine! Go check him out!

July, 2020

Note: It can be a lot of work documenting & making guides for builds like this, and credit it is always appreciated. More than anything, however, I’d love to see what you do with my info - if you do use the information on this page, please get in touch with me using the about/contact page; I’d love to see what you create!