Tymkrs GlitchCRT Video Synthesizer

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tymkrs
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Tymkrs GlitchCRT Video Synthesizer

Post by tymkrs » Mon Apr 05, 2021 2:41 pm

Hi folks,

New here, but long-time lurkers and Eurorack enthusiasts! We recently released a new product called the Tymkrs GlitchCRT. It's a 6hp Eurorack module capable of mixing and glitching at least 3 user-controlled composite visual inputs to the beat of user-chosen unbalanced audio input with intensity control! And allows you to make your own custom music videos!

Highly related to this module is our A2H and H2A modules which convert composite video to HDMI and HDMI to composite video if you want the freedom to mix/glitch those sources in. And if you want to be able to stream the result, these modules are super useful as well!

Thought I'd share some of the cool things we've come up with in our experiments:

One of my personal favorites:
In this test, the audio is an Elektron Model:Samples. There are three video sources. The first video source is a live camera feed of the test bench. The second video source is a Super Nintendo running the Secret of Mana title screen. The third video source is a Commodore 64 running a classic BASIC infinite maze program. The video output of Glitch CRT is being projected onto the test bench by an old LCD projector. While the test is running, I am adjusting the balance between the sources (sampler, camera, snes, c64) while performing live on the groove box. I particularly liked how the audio glitch turned a projector into a lightshow that reacted to the music:



Deliberately using delays caused by video conversion to set up video feedback loops that create a lava-lamp/modern-art style music video with music coming from our studio:



Experiments with combining NTSC and PAL signals:


And some basic glitches depending on how a static image reacts to different wave forms:



And even effects (echo/reverb, etc)



The Tymkrs GlitchCRT is available: https://www.tindie.com/products/tymkrs/ ... ck-module/
Tymkrs A2H Eurorack Module is available: https://www.tindie.com/products/tymkrs/ ... ck-module/
Tymkrs H2A Eurorack Module is available: https://www.tindie.com/products/tymkrs/ ... ck-module/

Let us know if you have any questions or want to see any other types of experiments!
Last edited by tymkrs on Tue Apr 06, 2021 2:10 pm, edited 1 time in total.

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Addam
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Re: Tymkrs GlitchCRT Video Synthesizer

Post by Addam » Tue Apr 06, 2021 9:37 am

Looks interesting and prices are nice. I'm very new to this so feel free to correct any misconceptions.

For the HDMI to composite module - will it always output 4:3 regardless of what the hdmi output is? Is the video signal the H2A spits out compatible with the LZX standard (0-1V I believe)?

Perhaps this should go in the video synthesis subforum?

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Kent
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Re: Tymkrs GlitchCRT Video Synthesizer

Post by Kent » Tue Apr 06, 2021 9:59 am

Yes, moved to the Video Synth sub-forum.

Let me welcome Tymkrs to the forum. Glad to have you here. I just discovered your wares 2 nights ago and it got my DIY trigger finger all itchy! Would love to build some of your toys.

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Re: Tymkrs GlitchCRT Video Synthesizer

Post by tymkrs » Tue Apr 06, 2021 1:57 pm

Sure thing Addam:

The h2a module does indeed output a 4:3 aspect ratio. It doesn't do any squeezing or letter boxing, so the extra information simply falls off the sides. The output is a standard NTSC or PAL signal of a typical composite video output level.

For the LZX stuff, you might be thinking of the control voltages they use to describe discrete aspects of a signal (for example one of the colors) during synthesis before the elements become integrated together into a fully functional output signal?

Thanks for the warm welcome Kent!

Most of the diy kit items in our shop are from about five years ago. It was around then that we were asked to our first electronic conference badge design. Things quickly escalated, and we were doing badges for conferences all over, so kits became back burner. For obvious reasons, there were no conferences this past year. Instead of moping, we took the opportunity to spend a year in the lab developing a whole suite of synthesizer modules. Bulkhead, Glitch CRT, a2h and h2a are up so far.

I wanted to get some of the video stuff up first so that we could use those to help demo all the upcoming audio modules.

Manufacturing is a bit ... odd ... at the moment, so we're rolling things out softly. Though, if I'm being honest, releasing a product in small handmade batches has been way less stressful than say the 24,000 units we delivered for DEFCON, haha. Getting back to our nerdy synth roots feels pretty great too.

@whixr / @tymkrs

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Re: Tymkrs GlitchCRT Video Synthesizer

Post by joem » Tue Apr 06, 2021 4:17 pm

LZX modules deal with luma signals in the 0-1V range in addition to CV in that range. (Though depending on the module, CV can be outside of that range too... some modules have attenuators on the CV inputs, some have attenuverters on the CV inputs, some respond to negative CV.) It's a nice format, and keeping the luma signals to 0-1V makes things easier for component selection and IC slew rates.

It looks like the Glitch CRT is a passive mixer, so there'd be no (reasonable) way to change an AC-coupled composite signal into a DC-restored 0-1V luma signal. If there aren't any capacitors in the signal path to force AC-coupling, you could probably use it with LZX 0-1V signals, but I'm not sure there'd be any advantage over using any other passive mixer (or "dirty mixer" as they're often called in the video/glitch world) in that case.

The H2a should output an AC-coupled (not 0-1V) signal, since it outputs a composite signal. So if you wanted to use it with LZX stuff, you'd need to run it into a composite input on a module (like on the Visual Cortex, or Cadet Input, or the upcoming TBC2 or Chromagnon modules). I think some of the existing composite inputs in LZX gear need 480i (for ntsc) or 576i (for pal) specifically, and the h2a documentation doesn't explicitly state if that's what it produces. (Upcoming LZX gear should definitely handle more variations though.)

(tymkrs, please correct me if I made any incorrect assumptions about your products!)

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Re: Tymkrs GlitchCRT Video Synthesizer

Post by Addam » Tue Apr 06, 2021 8:15 pm

tymkrs wrote:
Tue Apr 06, 2021 1:57 pm

The h2a module does indeed output a 4:3 aspect ratio. It doesn't do any squeezing or letter boxing, so the extra information simply falls off the sides. The output is a standard NTSC or PAL signal of a typical composite video output level.
Thanks, that sounds good. I'm looking for something easy just to goof around with.
joem wrote:
Tue Apr 06, 2021 4:17 pm
LZX modules deal with luma signals in the 0-1V range in addition to CV in that range. (Though depending on the module, CV can be outside of that range too... some modules have attenuators on the CV inputs, some have attenuverters on the CV inputs, some respond to negative CV.) It's a nice format, and keeping the luma signals to 0-1V makes things easier for component selection and IC slew rates.

It looks like the Glitch CRT is a passive mixer, so there'd be no (reasonable) way to change an AC-coupled composite signal into a DC-restored 0-1V luma signal. If there aren't any capacitors in the signal path to force AC-coupling, you could probably use it with LZX 0-1V signals, but I'm not sure there'd be any advantage over using any other passive mixer (or "dirty mixer" as they're often called in the video/glitch world) in that case.

The H2a should output an AC-coupled (not 0-1V) signal, since it outputs a composite signal. So if you wanted to use it with LZX stuff, you'd need to run it into a composite input on a module (like on the Visual Cortex, or Cadet Input, or the upcoming TBC2 or Chromagnon modules). I think some of the existing composite inputs in LZX gear need 480i (for ntsc) or 576i (for pal) specifically, and the h2a documentation doesn't explicitly state if that's what it produces. (Upcoming LZX gear should definitely handle more variations though.)
Thanks joem. By DC-restored you mean essentially an offset added to get a bipolar signal into the positive voltage range (and potentially attenuated down to max 1V)?

I do have LZX Cadet 1, 2 and 3 (though not many "fun" modules yet) - would it be a fairly safe assumption that I could plug the composite output from the Tymkrs hdmi to composite module into the sync gen, into the video input, etc. (typical use case) and then send that around to other modules?

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Re: Tymkrs GlitchCRT Video Synthesizer

Post by Electronicvibes » Wed Apr 07, 2021 9:24 am

Exactly what I was looking for, order placed today and the Tymkrses are already on their way 🥳

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Re: Tymkrs GlitchCRT Video Synthesizer

Post by tymkrs » Wed Apr 07, 2021 2:39 pm

joem:

The composite input upper section of the Glitch CRT does indeed function in a similar manner as the 'dirty mixer' popular with lofi video and glitch artists. As such, there is no capacitor in series with the signal.

The typical dirty mixer can be as simple as a single potentiometer; center output, outside legs being two inputs. This allows cross fading between two (not time base corrected) signals. It is a great super cheap DIY project for anyone who is interested in dipping their toes into this kind of thing.

Glitch CRT's passive mixer section is a bit different. Each of the three composite inputs has it own variable resistor between the input and the output bus. This is not the right way to passively mix signals, and certainly not the right way to mix unsynced signals - but that is the goal here: to do it wrong on purpose, because we're punk and the National Television System Committee isn't the boss of us, talk hard!

However, the lower section of Glitch CRT is a whole other animal entirely. That is an active circuit which vampire powers itself by rectifying the audio input signal and makes use of the non-linear behavior of NPN bases to selectively flood 'extra' composite signals through onto the output bus as the energy level of the audio signal changes.

As such, when using the audio input section, some of the rectified audio can potentially get onto the bus (base to emitter) which will offset the signal up a tiny bit. In theory, this results in the luma being hotter as the average audio level goes up (resulting in the brightness effects seen in the Glitch CRT experiment videos).

As for 480i and 576i, yeah h2a should work fine with inputs expecting either of those.

@whixr / @tymkrs

tymkrs
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Re: Tymkrs GlitchCRT Video Synthesizer

Post by tymkrs » Wed Apr 07, 2021 2:56 pm

Electronicvibes wrote:
Wed Apr 07, 2021 9:24 am
Exactly what I was looking for, order placed today and the Tymkrses are already on their way 🥳
^o^ Let us know if you make a youtube showing off the glitches, I'm happy to add it to our playlist!

@atdiy/@tymkrs

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Re: Tymkrs GlitchCRT Video Synthesizer

Post by joem » Wed Apr 07, 2021 4:08 pm

Addam wrote:
Tue Apr 06, 2021 8:15 pm
Thanks joem. By DC-restored you mean essentially an offset added to get a bipolar signal into the positive voltage range (and potentially attenuated down to max 1V)?
I think DC restoration is a little more complex than just adding an offset, though I'll admit I'm not entirely sure. I think because of the way AC-coupling centers things at 0V, it makes it a little more complicated.
Addam wrote:
Tue Apr 06, 2021 8:15 pm
I do have LZX Cadet 1, 2 and 3 (though not many "fun" modules yet) - would it be a fairly safe assumption that I could plug the composite output from the Tymkrs hdmi to composite module into the sync gen, into the video input, etc. (typical use case) and then send that around to other modules?
Yeah, that should work, as far as I know.

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Re: Tymkrs GlitchCRT Video Synthesizer

Post by joem » Wed Apr 07, 2021 4:13 pm

Thanks for clearing that up, tymkrs! I forgot to say before: Cool modules! Always good to see more video modules out there!
tymkrs wrote:
Wed Apr 07, 2021 2:39 pm
but that is the goal here: to do it wrong on purpose, because we're punk and the National Television System Committee isn't the boss of us, talk hard!
As someone who's watched Pump Up The Volume far too many times, I truly appreciate the reference! (Maybe I'm due for another rewatch? Hmm....)

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