Blinky patch cables

https://www.kickstarter.com/projects/candycordhalo/halo-a-light-up-patch-cable-from-myvolts-x-andrew-huang?utm_source=mv-shop&utm_medium=precampaign&utm_campaign=halo

Do you think if we make enough noise they night do a 1/4" series?

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At €8 each I hope not

Screenshot from 2022-11-25 06-53-13
Screenshot from 2022-11-25 06-53-22

At least they got that right.

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I found this guide for making light up ‘CV indicator’ cables with long flexible noodle LEDs. They’re only cosmetic though so don’t actually carry any signals. You connect the positive end of the LED to the tip of one jack plugged into the signal you want to monitor and ground the other end with a second jack.

It might be feasible to use some thin clear heat shrink tubing to bundle a noodle and cable together.

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“This setup [with a 220Ω resistor] assumes for a 5V maximum output from your CV synth.” and the forward voltage is 3 V. I don’t see a datasheet or other information source besides what it says on the sales page. “Since the LEDs are in parallel, you only need 3V to light 'em up.”

With 5 V supply and 3 V forward voltage, the drop across the resistor is 2 V and current is about 10 mA. That’s divided between however many LEDs there are. The nOOds are 30 cm long, so about 30 mA per meter.

A lot of EGs put out ~8 V or so at maximum so you’d probably want a larger resistor. But it would only light up for the upper portion of the envelope, above 3 V.

The Halo kickstarter has a lot of verbiage on the page and maybe I overlooked it, but I didn’t see anything about maximum voltage, forward voltage, or current draw for that. If it’s only one LED per plug and if it’s a low current (high brightness) one maybe it won’t add up to a lot of current draw for a typical patch… maybe?

What’ll it do to your CV, though? A 220Ω resistor + LED to ground after a module’s 1k output resistor forms a (voltage-dependent) voltage divider which would badly affect the CV:

Maybe the Halo cables use low current LEDs with much larger resistors, e.g. 6.8k:

but they don’t say… In any case it’s effectively reducing the input impedance of the downstream module from 100k to whatever the resistor is.

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I found the FAQ section:

What we found is that the voltage change was negligible. By which we mean it was changed more by having a longer cable, than it was by having an LED in it.

Uh, really? Hm.

The cables will light up when a signal with a voltage between 3v and 12V is present.

Can we get our notation at least consistent, guys? Anyway, there’s your forward and maximum voltages. For a 0–5 V signal it’ll light up only for 40% of the signal range.

A number of our more experienced testers have pointed this out to us and identified examples of ways these could create irregular behaviour.
The good news is that none of these will be damaging to you, or your equipment. The bad news is that you may have to replace the halo cable with a standard patch cable.
Probably the most common example of this is when using certain cycling outputs, where drawing voltage from a jack to power an LED results in the cycle being stalled. (We have tested this with other modular LED indicator products and it happens with all of them, not just ours!) So far we’ve noticed this behavior on three modules:
Make Noise Maths (unity output only)
Erica Synths Black Dual ASR EG
Buchla Tiptop 281t (Non-operational with LED patch cables)

They still don’t say what the current draw and impedance are.

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Boo! Hiss! Tish pshwa nonsense! :grin:

Every time I see a showcase of disposable income like this product advertised, costing an absolute fortune for some slick looking unnecessary gadget, i vow to build my setup to look 5% cheaper and less polished than before

(Also yeah, “wouldn’t that cause voltage drop” was the first thing that came to mind when I have experienced firsthand what happens adding leds to unbuffered circuits lol)

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