VT-Phasor Twin Tremolo

[The Dude]

I see what looks to be a hole in the side of the device where an LED might have been inserted, or is that just a reflection in the picture? I can't tell for sure.

[bobloblaws]

I see what looks to be a hole in the side of the device where an LED might have been inserted, or is that just a reflection in the picture? I can't tell for sure.

Now that you mention it, I think that might actually be the LED itself, see latest pic. I'm also noticing that the black plastic part has glue around the bottom. originally I was thinking I might have to remove the PCB from the chassis and remove a ton of solder to see what's in/under there, it might be a matter of scoring the glue and prying it up.

[g1]

I think I count 10 traces going to it, which is what I had expected for 4 LDR's and a single LED. Yes, it's possible the plastic is just a cover. Don't force it in case it is not, it should come off easily if it's just a cover.
Those stubs may be test points.

[mauman]

The dome covers the LED and four LRDs, and it excludes light from the LDRs when the LED is off. It's a common arrangement for similar circuits. The inside of the dome can be matte or reflective, depending on the amount of light bounce needed. Here's a Uni-Vibe clone effect pedal, with and without a reflective dome.

[glebert]

I think Mauman called it right. Looking at schematics, this seems pretty much like a clone of the Uni-Vibe, but mixing NPN and PNP (though there may be versions of the Uni-Vibe that did that too)

VT


Uni-Vibe (from https://revolutiondeux.blogspot.com/...easy-vibe.html)