#12

I’m not an expert, but if you google “vactrol rohs” you’ll find a lot of people claiming that vactrols are in fact not legal to sell in the EU, due to the cadmium in the LDR.

#13

My grandmother’s dementia was likely caused by keeping porcelain painting brushes wet in her mouth as she worked over the decades. Cadmium red no longer exists for this very reason.

#14

TIL.
It looks, however, like in the EU there was a bit of back and forth on Cadmium pigments, in the end deciding in favour of Cd, by reason of not having enough evidence to back what would otherwise end up as an arbitrary ban, so paints are still on the market…

#15

Interesting. I hadn’t realized that. I suppose she retired from her painting during the period when the ban was active.

#16

just to confirm that of the 50 or 60 photoresistors listed on digikey, none appear to be ROHS compliant now. wild!

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#17

So glad I have most of the vactrol gear i might want already.

and it’s not just modular. Where would I get that amazing Morley Wah sound from without photoresistors?!

And not to go off topic too much, but it’s the same with rosewood in guitars. That’ll be disappearing from most guitars over the next few months if it hasn’t already. You can no longer get a Fender Standard P bass with a rosewood fingerboard new. My bass was so cheap, and yet uses a material we’ll now consider luxury.

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#18

are the isms lpgs’ vactrols made from anything special? perhaps @Galapagoose or @tehn can provide a bit of info. all three of mine seem remarkably well-matched.

#19

Especially if you think that photoresistors were exempt from RoHS because of difficult substitution, but the exemption expired. In 2013.

#20

Sorry, I’m a bit naive on the subject, but what makes it so difficult to try and model these things digitally or in software?

#21

420 go to used electronics graveyards and harvest opto-isolators every day.

#22

The math may seem a bit heavy, but the circuits are pretty simple.

A DIGITAL MODEL OF THE BUCHLA LOWPASS-GATE
http://dafx13.nuim.ie/papers/44.dafx2013_submission_56.pdf

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#23

nothing in particular, but software is software. you know?

in analog, i think you can get plenty close with opamps, its just a part count/cost thing, and you lose some of the, i dunno, “grit”

and you can’t play your software mixer with a flashlight

sorry, but that’s the hand-waviest approach to modeling the vactrol that i can imagine. they just pop an integrator in there and modulate the integration time by the level a wee bit (like in any basic compressor plugin). then: “Adapting full models of photoconductor transient dynamics [25] for musical signal processing use is a significant task, and left for future work.”

most of the paper is about modelling the lowpass sallen-keyish circuit and the control path.

(and hey, nothing wrong with that, the simple model captures the broad behavior, just don’t go looking for too much special insight there)

in any case, i now feel extra lucky to have my little stash of VTL5C3.

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#24

buyin’ up Meng Qi dplpg’s like canned goods and water…

#25

analogue haven should pay you commission on this hahaha

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#26

spreading the love is payment enough. stole @tehn’s teletype studies trick – gating constant voltage w/ pulses into Mangrove’s AIR control opens fucks my shit right up.

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#27

Sold me on two. It was a “Hey, why DONT I have passive lpgs filling up the gaps” moment.

#28

Btw, you can also buy stuff directly from MengQi, though shipping might be a bit cheaper from AH for people in the US…

Several Folktek designs (including the Mescaline and Matter) are also supposed to be full of vactrols but Mental (Mescaline’s Matter-like module) seems to be all SMD. Are there SMD vactrols ?

#29

Not that I know of - but almost all euro contains some non-SMD elements like pots, sockets, power headers are often non-SMD, do the vactrols would be added at that point

#30

there are SMD optocouplers, maybe there’s one with an appropriate response curve

#32

I feel so incredibly fortunate that I snagged me a Natural Gate in that frenzy.

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