LZX Voltage Interface (10v-1v)

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Predictability and repeatability are important to me. Yes, that’s probably foolish. In the analog world, one never steps in the same river twice. But the control freak in me wants to minimize the chaos as much as possible. So for that reason, if no other, I’d rather not have any potentiometers involved in the voltage conversion. Plus I’m not thrilled with the idea of any inline gadgets and gizmos. The noodle soup is already thick enough.

When The Analog Thing finally arrives, and if I have the brain power to figure out how to use it, I’d like to be able to just plug it in. That means bidirectional conversion 1V <–> 10V.

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Count this post as another request for a bank of divide by 10 in some form. I guess using two channels of a divide by 5 would be acceptable if it passed bipolar signal.

4ms Quad Pingable LFO can be configured to be +/-5V or 0V/+10V, and I’d rather run it in unipolar if the rest of my system could support it.

I love the chaotic Non Linear Circuits modules but they all run hot and need to be tamed, I am pretty sure getting to +/-10V, so I need to match them with their own dedicated scaling.

I’m yet to build a handful of Visible Signals’ Wrangler modules, which appear to be my best option so far, but losing 4HP per signal is a bit painful.

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Doesn’t the 10x amplification that you want to run your LZX signals through also raise the noise floor, though? So while you might get a bit better signal-to-noise ration in the audio module than you would with 5x amplification, you’re also raising the noise floor of the signal that module will be processing, so it’s a trade off.

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I’m talking about noise within the audio modules. If a module is designed to use a 0 to 10 V range, and you send it less than that, you might get less than satisfactory results. Could be noisy, and/or could have issues with functionality.

I should also mention that I’m planning to add at least one Tiptop Buchla clone, which is most definitely 0-10V.

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One way to approach an interface would be one switch to set “source” scale, and one to set “destination” scale. Scales would be 1V, 2V, 5V, 10V, +/-1V, +/-2V, +/-5V, +/-10V on both sides (8 options.) I think that’s what it would take to do a “universal converter”, but that’s quite a lot of module (2x 8 position rotary switches) for each channel.

The most practical universal option if you have to pick just one is a simple divide by 5 attenuator. That brings the largest input +/-10V into the LZX headroom range of +/-2V, and translates 0-5V CV sources (pretty common standard Euro levels) to 0-1V exactly, and requires nothing but in/out jacks.

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I heard that sometimes a easy mod makes a nlc module suitable for 1v

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hello everyone. i can think of a handful of examples of scaling down audio modular 5v down to 1v lzx video system, but not too many, being an amateur. and i’ve seen scalers that go the other way, 1v to 5v, for which i can think of even less uses. Please would someone take a second to share some theoretical examples or uses for such a device, going either way. I knew about 50Hz PAL being the ?vertical? scan rate, i believe PAL ?horizontal? starts at about 15.6 kHz. Whereas lasers @ 40kpps for instance are designed to best respond to sub 50Hz and this adds to my confusion, sorry. thanks for the help, best wishes

i prefer humans and dont trust ai but it tells me:

Scaling 5V Down to 1V (Audio to Video)

  1. Using Audio Modulation for Video Synthesis – If you want an audio oscillator or LFO from your Eurorack to influence video parameters in an LZX system, you need to scale the voltage down so that it maps properly without exceeding 1V.
  2. Envelopes for Brightness Modulation – A 5V (or 10V) envelope generator could be attenuated to 1V to control brightness or contrast in a video system.
  3. Low-Frequency Oscillators (LFOs) for Video Effects – Many LFOs output at 5V or 10V, and scaling them to 1V allows for smooth control over video elements.
  4. Audio Signal Translation to Video – Directly visualizing audio waveforms requires scaling them down. Otherwise, they’d clip within the LZX range.

Scaling 1V Up to 5V (Video to Audio)

  1. Using Video Signals as Modulation in Eurorack – If you want to use an LZX output to modulate a Eurorack synth (such as an FM input on an oscillator), you often need to boost it to 5V or 10V.
  2. Video LFOs Controlling Sound Parameters – Some video LFOs generate interesting waveshapes that might be useful for audio synthesis, but they need to be scaled up to impact CV parameters effectively.
  3. Extracting Edges or Transitions from Video – Some video signals (like a keyer output) might be 0V to 1V but could be amplified and used as a trigger or gate in an audio system.

Additional Considerations

  • Eurorack Audio Voltages: Yes, audio signals in Eurorack can be as high as ±5V (or ±10V peak-to-peak in some cases).
  • Video Rates vs. Audio Rates: Your understanding of PAL is mostly correct—50Hz is the vertical refresh rate, and horizontal scan rate is around 15.625 kHz. For lasers, 40kpps (points per second) is a scanning speed but relates more to how fast the mirrors move rather than a standard refresh rate.
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29

you can experiment with the effects of sending video through audio modules.
sometimes with cool results, other times not so much.
The opamps used in audio circuits can add blurred edges .

examples for 0 +1v to -5v +5v Scaler / -5v +5v to 0v +1v Scaler setups

-video VCO → scaler → FM input of synced audio oscillator → Scaler → video synth
(for alternative waveshapes and experiments)

-synthesised shape or camera input → Scaler → audio wavefolder , delay, FX → Scaler → video synth
(distorting shapes , glitch effects, with CV over certain weird effects)

-video output → Scaler → direct audio output
(for 1:1 audio video performances, the audio can be noisy or abstract)

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You seem to be confusing voltage amplitude with oscillator frequency.

The frequency, measured in Hertz, is the time it takes an oscillator to complete one cycle of the waveform.

The amplitude, measured in volts, is the value of the signal at any point in time.

AI is not wrong in this case.

Conversion from 5v to 1v is more common, in order to control video modules with audio modules.
For example, I want to modulate some video property such as a key threshold. I can do that with LZX compatible modules, but my options are limited. If I want to modulate that property with, for example, Ornament & Crime Plus, I need to convert its 5v outputs to match the 1v input on my keyer.

But the other way is also useful. Conversion from 1v to 5v lets us control audio modules with video modules. Many people have built up audio systems first, then add the video modules to the mix. This means that they have plenty of audio oscillators, etc. on hand to control other audio modules, which in turn control video modules.

But some of us have video-only systems that incorporate audio modules for controlling video, but not for generating or controlling sound. At all. I literally have no audio oscillators, filters, etc. I have audio modules whose sole purpose is to provide low frequency control voltages to the video modules.

In that scenario, we need to convert from 1v to 5v to get the full functionality out of the system. For example, if I want to drive the Ornament & Crime Plus with LZX compatible oscillators, I need to multiply that 1v LZX output by five in order to bring it into the necessary range for the OCP input.

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