univibe speed control

SmellsExcellent · February 17, 2007, 11:34:25 AM

can anybody help me with wiring an original univibe speed it control pot? i got this one from a dude that had already tampered with it and i'm trying to stick the dual 100k into the housing itself since i dont have a foot controller. i know basic electronics but this is a bit too complicated for me to just look at and figure out... i have green, yellow, white and blue wires and i just need a pic or schematic of a correctly connected control pot.

thanks,
marc

tcobretti · February 17, 2007, 11:47:23 AM

http://geofex.com/FX_images/vibeschm.pdf

If this is an original Univibe, please, please, please don't drill any holes or permanently damage an original Univibe. They are worth many hundreds of dollars and almost impossible to find.

With a little effort and expense you could build a pedal to work with it and leave it undamaged.

jonathan perez · February 17, 2007, 11:53:26 AM

dunlop sells expression pedals...buy one of those

SmellsExcellent · February 17, 2007, 12:08:30 PM

trust me, i have no intention of @#$%ing with the original... i'm ashamed for the dude who sold it to me (tried to tell me it _was_ original...) because he had it wired up such that it did nothing at all and nothing worked... i've come a long way with this hoss and all i got left is the speed. anyway, i have that diagram and it doesn't work for me. maybe this is the wrong pot, maybe i screwed up the wires somehow... as far as i know, though, that diagram is not the same layout as the original uni--this is why a pic with come colors would help... then i'd know exactly what should go where. maybe ill check on ebay hahaa.

mars

jonathan perez · February 17, 2007, 12:12:24 PM

well, we dont typically base diagrams off of colors...for those of us who are colorblind, it wouldnt make much sense.

the schem from geofex aint original? hmm...odd...

heres what you can do, then.

go to http://www.sweetsound.com/ and talk to Bob Sweet, see if you can work it out with him unlike certain other Boo-teekers, hes a nice guy.

that, or wait for RG's response.

SmellsExcellent · February 17, 2007, 12:21:04 PM

hahah then "we" donsn't necessarily include me because i dont know as much as you guy. haha.

tcobretti · February 17, 2007, 12:21:48 PM

The reissue pedal won't work as is. The original uses a different type of wire, something like a midi cable.

I'm pretty sure RG said that schem is correct, but the layout is likely different.

If you look in the bottom right hand corner of the schem I linked to, you can see how the pot is wired to the circuit. Using the wiring diagram and the link below which gives values you should be able to figure what you have done wrong.

http://www.geofex.com/Article_Folders/univibe/vibeupdate.pdf

jonathan perez · February 17, 2007, 12:31:53 PM

Quote from: SmellsExcellent on February 17, 2007, 12:21:04 PM
hahah then "we" donsn't necessarily include me because i dont know as much as you guy. haha.

niether do i?

SmellsExcellent · February 17, 2007, 12:36:36 PM

yeah... shem is correct but layout is VERY different. and my voltmeter is at work around so i cant do that... i've used the diagram already and i cant get it to work.

&TBOM: cheers.

jonathan perez · February 17, 2007, 01:10:30 PM

k

R.G. · February 17, 2007, 02:55:33 PM

The schematic from GEO is original except for the 15V regulator. The original used two resistors and caps and did not regulate at all. The rest of it is identical.

Smells, here's what you have to do. You need to identify the wiring pads on your board which match the wiring pads on my board. You can do this two ways. First, you could trace the wiring pads on your board back into the board until you hit identical value components. Second, you could take good digital picture of your board and I could identify the pads for you if the pics are good enough. Top and bottom would be helpful.

Me not having a picture of your board to refer to means that I can't tell you which is which.

SmellsExcellent · February 18, 2007, 01:58:49 PM

here:

http://www.thegravelroad.org/gfx/uni/uni_boardtop.jpg

http://www.thegravelroad.org/gfx/uni/uni_boardbottom.jpg

thanks for all the help.

m

Quote from: R.G. on February 17, 2007, 02:55:33 PM
The schematic from GEO is original except for the 15V regulator. The original used two resistors and caps and did not regulate at all. The rest of it is identical.

Smells, here's what you have to do. You need to identify the wiring pads on your board which match the wiring pads on my board. You can do this two ways. First, you could trace the wiring pads on your board back into the board until you hit identical value components. Second, you could take good digital picture of your board and I could identify the pads for you if the pics are good enough. Top and bottom would be helpful.

Me not having a picture of your board to refer to means that I can't tell you which is which.

R.G. · February 18, 2007, 03:23:55 PM

That was fine. The speed control hooks to pads numbered 7, 8 and 12 on the bottom of the board if I didn't get my eyes crossed.

The pot is hooked up with the wipers and two end lugs all commoned. That connection goes to pad 12. The two unconnected ends of the pots go to 7 and 8. The wire in your photo that goes to 12 is yellow(ish) and the ones to 7 and 8 are blue and white.

SmellsExcellent · February 18, 2007, 03:41:30 PM

Quote from: R.G. on February 18, 2007, 03:23:55 PM
That was fine. The speed control hooks to pads numbered 7, 8 and 12 on the bottom of the board if I didn't get my eyes crossed.

The pot is hooked up with the wipers and two end lugs all commoned. That connection goes to pad 12. The two unconnected ends of the pots go to 7 and 8. The wire in your photo that goes to 12 is yellow(ish) and the ones to 7 and 8 are blue and white.

k cool.. and the green, looks like pad 6, is a ground or??? on the original plug there were leads connected to ground and the green in addition... what does that do?

m

R.G. · February 18, 2007, 03:48:08 PM

I'll have to got back and look some more. It could be the "cancel" that killed the effect. What it does is just short out the signal to the lamp driver, so the 'vibe doesn't go vibing.

SmellsExcellent · February 18, 2007, 03:57:17 PM

riiight... on the pedal. cool. welp i got it wired and still no oscillation. guess something else must be broken. any ideas? ill go through the schematic as best i can to see what's up. do the a,b,c,d,e,f, etc pads on the geo correspond to the 1,2,3,4 pads on the original uni? if so i hope i can go through there and at least check out that b.s... anyway, off to work! thanks for your patience.

marc

R.G. · February 18, 2007, 05:11:23 PM

Quotewelp i got it wired and still no oscillation. guess something else must be broken. any ideas?

Bummer. Low gain in the two transistors which do the LFO, bad driver transistor, bad caps or resistor in the LFO.

You know, something I did to check the things out was to use a pair of 47K resistors in place of the pot for temporarily getting the LFO running. That eliminates the pot wiring as a problem. Just tack-solder them on top of the board. Then go looking for DC voltages in the LFO and lamp driver circuit. Does the lamp light at all? Is it open? Any voltage on the lamp driver? Any response to changing the lamp trimmer?

Quotedo the a,b,c,d,e,f, etc pads on the geo correspond to the 1,2,3,4 pads on the original uni?

Only by accident. The Neovibe is a completely new board layout, about half the size of the original. The pads are the same circuit points, but I lettered them for reference in wiring up the Neovibe, not to correspond.

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univibe speed control