Build Your Own CRT Wobbulator (Raster Manipulation Unit) with Jen Kutler
Saturday, November 4th at 11 AM, Ithaca, NY
Led by Jen Kutler, each participant is asked to bring two working CRT televisions- one as the donor CRT and one as the CRT to be modified and become the wobbulator.
Tools and soldering irons will be provided. The cost of the workshop is between $125 and $175 per person depending on location and preregistration is necessary at jenkutler.com/workshops. Registration closes one week before the beginning of each scheduled workshop to ensure that we have enough materials and tools on hand. Due to the nature of high voltage electronics, each participant is required to sign a liability release form. Please direct all questions to jenkutleraudio@gmail.com.
Note: This workshop includes step-by-step guidance and construction of the actual Wobbulator. The participant is expected to bring their own (2) CRT monitors – one to use for parts and the other to modify. The donor CRT should be larger than the CRT to become the wobbulator. We have had the best results with wobbulator CRTs that are in the 5-9” range combined with donor CRTs in the 13-19” range. The workshop cost includes wire for winding the S coil, tools, and other miscellaneous parts, testing and troubleshooting. The workshop cost does not include or cover signal generators or oscillators (though generic parts are suitable and easy to come by). The focus of the workshop is on parts that are not commercially accessible. Oscillators and amplifiers will be available during the workshop to test modified CRTs. Since modifying CRTs is an experimental practice and every CRT is a bit different, there is no guarantee that every participant will leave the workshop with a working wobbulator.
If you really want to have a wobbulator for your project or studio and do not want to go through the process of building it yourself, reach out to me and I would be happy to discuss building one for you.
About the Wobbulator:
"A raster manipulation unit or 'wobbulator' is a prepared television which permits a wide variety of treatments to be performed on video images; this is accomplished by the addition of extra yokes to a conventional black and white receiver and by the application of signals derived from audio or function generators on the yokes. The unit is a receiver modified for monitor capability; all of the distortions can thus be performed either on broadcast signals or, when the unit is used as a monitor, on images from a live or prerecorded source. Although the image manipulations cannot be recorded directly, they can be recorded by using an optical interface. The patterns displayed on the unit are rescanned; a camera is pointed directly at the picture tube surface and scans the display. The video signal from this rescan camera is then input to a videotape recorder for immediate recording or to a processing system for further image treatment. The notion of prepared television has been investigated by a number of video artists and engineers; this particular set of modifications was popularized by Nam June Paik." - Excerpt from “Raster Manipulation Unit: Operation and Construction (1980)” from The Experimental Television Center by Sherry Hocking, Richard Brewster and Walter Wright.
You can learn more about Jen Kutler at jenkutler.com.
Wobbulator Workshop FAQ
What kind of TVs do I need to bring?
The best bet for your first wobbulator build is a small 5” black and white analog travel TV - A Coby CX-TV1 or similar shouldn’t cost you more than $30 or so with shipping and is ideal for this workshop. The basic rule is that you want a TV with the smallest possible tube neck diameter and the smallest possible stock deflection yoke. For the donor TV (which will be donating it’s deflection yoke) you are looking for a TV with a larger deflection yoke and larger diameter tube neck. Just because a TV has a larger screen does not mean that the tube neck will necessarily be larger. Most consumer non-flat screen TVs will have a suitable deflection yoke. They can be black and white or color and they don’t even need to turn on. Finally, avoid computer CRT monitors. As a rule of thumb, don’t try to modify any electronic equipment that you care about. There is always a chance that the equipment will be destroyed in the process. Do not buy expensive TVs for this workshop. Please test your future wobbulator TV to make sure that it works properly before the workshop. You don’t want to go through the whole process of building a wobbulator only to find out that you used a faulty TV from the beginning.
What tools should I bring?
No tools are necessary but if you have extra on hand and feel inclined, extra drills and multi-meters are always helpful.
What do I need to use my wobbulator at home after the workshop is over?
The added deflection coils each require their own audio amplifier channel and individual signal. The signals can come from pretty much any signal generating device - your computer’s sound card, a signal from your eurorack modules, etc. The signal NEEDS to be amplified with an audio power amplifier. In other words you cannot connect your audio signal straight into the deflection coils. A power amplifier can be a car audio amplifier, it can be a rackmount pro audio power amplifier or even a consumer stereo receiver with a built in amplifier. At a minimum this amplifier should be able to provide 75 watts per channel. Since there are three added deflection coils, you need three 75 watts or more amplifier channels. These types of amplifiers are readily available off the shelf so they are not included or covered in this workshop. The workshop focuses on the wobbulator build itself which is typically only accessible if one builds it themselves.
I signed up for your workshop but now I can’t come. What is your cancellation policy?
I have to order enough parts and materials for each person that attends the workshop. If you cancel at the last minute, I have to eat that cost. At the same time, I am not a monster and I understand that shit happens. If you cancel a week before the start of the workshop, its no problem. If you cancel within a week of the workshop, I can refund your payment minus $25 for the parts.
I didn’t sign up for your workshop but I really want to come at the last minute. Can I come?
Send me an email. It is possible I had a cancellation and a spot opened up.
I can’t come to your workshop in person but I really want to build a wobbulator. Can you show me how to do it over zoom?
This is a tough one. Working with CRTs can be dangerous for folks that don’t know what they’re doing and it is exceedingly difficult to troubleshoot potential issues over zoom without being able to get my hands in there. For individuals with experience working with electronics it is a possibility but will require you to have some weird tools on hand like a custom wire jig and some extra patience. For individuals that have little experience with electronics and safety around high voltage, I don’t feel comfortable walking you through it over zoom. So that leaves a few options - I can try to organize a workshop closer to where you are, or if you really want to have a wobbulator we can discuss my building one for you and shipping it. Send me an email.
Workshop Registration
Thank you for your interest. Looking forward to seeing you!