Component identification please

[Steve Blackdog]

40 year old Bell Electrolabs phaser.

I thought I would have a go at making a schematic of my old phaser pedal. No real purpose, other than to stretch my mind and if I get it right share it on here.

Straight away, I have come across components that I am unfamiliar with.

Any help with this black box?  It has a circular pin layout 14 pins on the circumference and  + & - connections in the middle. There is no writing on it.










Also, is this a diode?



Thanks in advance!

[duck_arse]

that silver stripey thing looks a lot like a polystyrene cap. as for the black box, at a guess, I'd say it was a led at the centre with a ring of ldr's around it. you can try and measure the voltage across the two centre pins, look for something like a led Vf. resistance measure across each the other pairs would prolly show high, as you'd have the supply off and the led/light source would be dark.

[Steve Blackdog]

Thanks for the explanation- it makes sense. I have no experience of using optocouplers/vactrols and need to do some more research.

Is the plastic black box just a cover to keep the light out then?  I can see that is glued to the pcb.

[bluebunny]

I think the duck's explanation is the most logical.  In which case, the box is a light shield.  Assuming the alleged LED isn't IR, can you see it light up through the translucent board?  (Turn the lights off.)

[Steve Blackdog]

Good idea, I will have to wait until it gets dark!