Know of a tremolo with 1 transistor for audio?

[blackieNYC]

I appear to have built some kind of modulator a couple years ago.  It has a dual op amp LFO, and just one transistor for the audio, and a vactrol.  Speed and depth controls. And too many wires.
Does anyone know of such a circuit? I didn't finish it, didn't document it, and I'm trying to figure it out. Hoping it is an established circuit. If I just made it up, I feel like I would have a schematic for it in the stack.
"What the heck is this thing?" Looking at your own project and drawing a complete blank - a pivotal milestone in one's pedalmaking to be sure. 

[Plexi]

Something like this?
http://sound.whsites.net/p49-f2.gif

[reddesert]

The Escobedo Wobbletron / Bigfoot Magnavibe uses a LED/LDR and a single transistor for audio.  The Wobbletron has a transistor LFO, but if you take a dual op amp LFO like in Culturejam's Shoot the Moon or Duovibe, and pair it with the Wobbletron output stage, that's close enough.