Just to be clear, this was fake hurt feelings to insert myself into the convo. I love pyramids, its one of my favorites.
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Crocodile tears? Makes sense.
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The idea is to add the light (e.g. at a high frequency and a slower pulse) from the LEDs to one LDR (see previous pic) 3 LEDs may be overkill but they can be used alternately, triggered from different sources. The switches should toggle the jacks (parallel to the respective LEDs) between internal LFO output (triangle, square, sine) and external (whatever) input. As said, not sure if it works out well, but I’m not afraid to try it 
I’m also not sure if I really need a sine wave LFO, the LM13700 could propably be used for something more exiting.
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sorry but i don’ t see and don’t understand the LDR part
what sort of cable have you made to plug it into the 3 leds XLR socket ?
EDIT :
I imagine a thing like that
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Yes, exactly like that but why 2 jacks ? ok, why not… for the wien bridge generator I’d need 2 LDRs with identical characteristic, but they already have these double vactrols. These are for generic use. This thread isn’t just about the generator anymore, it became my personal build progress.
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if you use only one jack, the LDR connect tip with GND ?
Oh, good point, now i get it. Haven’t thought that all the way through 
. The vactrol input on the “whatever” module on the other end cannot be a mono jack to ground then… unless the resistor or Pot in parallal is connected to ground with one leg.
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When I saved them from the trash I thought: Will I ever find a use for so many 9-pin sub-Ds ?
Today I made some powerrails with them because I don’t have enough male connectors for the 23 pin tuchels that are installed in the rack.
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Bloody genius adaptation. Bravo!
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Todays built: A little module with AC Power switch, Banana jacks for DC voltages and two 3.5 to 6.3 adapters mainly to fill that nasty gap.
None of the modules are 100% finished yet but it’s so satisfying to look at a full rack.
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It’s looking excellent!
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My setup is very proprietary. I need 24V and also something lower than +12V so I’m reusing these old wall warts.
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Todays progress: finished the Dual Vactrolled Wien Bridge Oscillator and added a Schmitt Trigger (Deadbug/Husky on the left) for the outputs to be able to select between sine and square. It’s the butchered modules from the start of this thread. I removed the output transformers, one was defective anyway. And I made a new frontplate.
The 9-pins can be used to apply a fixed frequency with 2 resistors (in parallel to the vactrols).
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The double LFO Vactrolator is finished and working.
…for a quick test I connected the LDR to one leg of the Wien Bridge Generator, it sounds a little like our 2 budgies.
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…and my daughter made some nice doodles for the soundmachine.
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sounds like little birdies.
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I posted this picture before. Next module will be a (quad? 1184ish) VCA using these boards.
If you redraw the circuit with discrete resistors (rather than the 10K SIPs) you see that U4B is a differential input stage for CV±.
Since these were used in an audio console, I guess that one CV was connected to the the channel fader and the other CV input to the VCA master fader. I hope I can group 4 together and have a master volume/VCA control somehow.
Tested one with ±12V and the module passes audio 
but noticed that there is a 5V reference used. I’d better make a proper ±15V PSU for this.
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That TA-101 made me curious, and google brought up a datasheet from a curiously named company:
(roman numbers say 1977, not 1776)
that there are otherwise few traces of on the internet, but via some patents mentioned in the datasheet it seems the circuits were designed by this guy.
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