An old, obscure, weird fuzz/wah/filter/noise/volume pedal from Japan dated from the the early 70s. Schematics and more info HERE. Note that a couple of resistor values was is incorrect in the original schematic but it has been corrected for the layout below.
Incredible! Thank you so much : it's the one with the old Korg (Keio) filter, right? i'm eyeballing this one for a good while :that's a great x-mas present, Fuzzhead!
ReplyDelete(I think I made a confusion with the Mr Multi, which is filter + phaser) : https://catalinbread.com/blogs/kulas-cabinet/korg-mr-multi
DeleteStill, I think this Synthesizer traveler is a "I must build it" for sure!
If i'm not mistaken, either this one or the Mr Multi features the discrete VCF from the might MaxiKorg800...
Funny you mention Mr Multi. I started on a layout for it today (with some mods by Deadend Fx)...but I have no clue when it will be finished since it is a biggie, 29x30. It sure looks and sounds like a a very interesting phaser/filter!
DeleteI think this one has the discrete filter you mention since Mr Multi is mostly powered by op amps.
awesome (both for knowing that this one should feature the VCF i'm after... and for knowing that you work on a Mr Multi vero layout)!
DeleteI can't start working on this one right now, but I will in the next weeks, and I will report how it works!
THanks again
... The user manual hosted on tonehome.de is will worth a look :D
ReplyDeletehttps://www.tonehome.de/keio/
How easy would it be to get rid of the "singing" part of the pedal (so we have "only" VCF+fuzz)?
lol, love that manual!D-:
DeleteDid some more reading about the Traveler. It appears that this inductorless version doesn't have a LFO section. It is possible that V2 have it but there is no schematic for it. :-(
But the Mr Multi layout is almost finished, hopefully I can upload it this evening.
Thank you, FuzzHead, and happy new year.
DeleteI didn't even know there had two versions of it, and that one featured a LFO !?
I think the v1 should really be good enough, and maybe that I'll manage to add a CV input for modulation later if I feel the need for it.
It's just the oscillator ("singing") part which seems useless to me nowadays, so getting rid of it would make the layout even simpler :)
Hi there. I'm going to have a crack at this as well but wonder if anyone can tell me what the purpose of the 1K trimpot is? Cheers!
ReplyDeleteThis is just a bit of a guess on my part, since I'm not familiar with this circuit. But leg 2 of the trimpot connects to that 10uF capacitor which then goes directly to the collector of Q6. So it could be that the transistor needs to be biased more precisely than a fixed resistor can do?
DeleteAltho, upon closer inspection, I see that Q6 is PNP and looks like it is getting a full 9v directly from the supply to the emitter. And that 10uF to trimpot arrangement than connects over to the 470ohm and 1k5 resistor, 100nF and then the wah pot. So it could be a fine tuner for the wah range? At this pint I'm going to say that a look at the schematic will probably get you more than my spitballing.
DeleteThanks for your reply and Brian below. For those following, schem is here: http://www.dirk-hendrik.com/temp/keio_synthesizer_traveler.pdf
DeleteR19/1K trim adjusts the resonance of the wah?
ReplyDelete