I bought this pedal off a second-hand shop in Tokyo a few years back, with no box, no manual. I kinda forgot it on a shelf for some time but recently started to use it again. I searched a bit online, but there's no much informations. A few second-hand ads stating it's from the 80's, maybe early 90's. As for the features, it has two chorus modes that I can't really differenciate, and one flanger mode. The Manual and Resonance knobs are inactive on choruses modes and only apply to the flanger mode. I emailed Guyatone and they told me that unfortunately a lot of paperwork and informations were lost over time and that they were now trying to gather it all back in order to put up an online library with all their gear and related informations. As for the sound, it sounds fairly alright. I don't have much experience with modulation pedals so maybe a chorus purist would laugh it off, but it sounds quite full and lush to my ears. Maybe a bit over the top, you're more on the jet side of flanger and even the chorus tends to do so with a drive in front of it. But for throwing big unapologetic psychedelic/doom/stoner riffs, it has something to it. It does not eat-up the low end at all. However I noticed that it tends to saturate / to gate when punched to hard into. I doubt it would be usable at all with an active bass. I don't know if that's a problem with this model or this very unit or if that's something quite common with vintage modulation pedals (I read some similar things about other vintage pedals, but again I'm not very knowledgeable about modulation). So here's with all I know and gathered about it. Now if anyone here knows anything about it, has a manual (even in Japanese), knows about these two choruses modes I can't really tell apart, knows if it's a copy of something or an original take by Guyatone, or even if you play(ed) with it and want to share about it, I'm looking forward to it! Thanks in advance!