Demystifying the MojoVibe

madbean · Post by **madbean** » 27 Oct 2010, 14:38

That's what I'm using in my clone. I've got signal and the LDR's respond to my hand over them. But, no bulb action. I have a bunch of different bulbs though, so hopefully one of them will work. I think I put an 18v bulb in, so I might try a 14v one instead. It actually does light up, but very faintly and it's not oscillating.

coldcraft · Post by **coldcraft** » 03 Dec 2010, 19:24

what wavelength at the LDRs most sensitive to?

gilmour_pugliese · Post by **gilmour_pugliese** » 03 Dec 2010, 20:36

just a question.. this transformer is OK for this circuit:

http://www.banzaimusic.com/Hahn-BVEI3032034.html

or a 15VAC (21VDC approx) is better?
http://www.banzaimusic.com/Hahn-BVEI3032033.html

vintagecharlie · Post by **vintagecharlie** » 07 Mar 2011, 09:34

outtahear wrote:No parts numbers, but here's a set O' LDRs and incandescent lamp courtesy of Uncle Bob hisself.
Same ones he used on his vibes, got 'em 12 or so years ago.

Has anyone seen a bulb like this one somewhere? Looks to be very close to the one in the old originals. Would be great to find something like that one in 28V, 40ma, or very close to it. (Probably not much of a difference other bulbs, but still would be cool).

Thanks!

VintageCharlie

Frabbio · Post by **Frabbio** » 07 Mar 2011, 11:08

Hi guys, i have a suggestion for Madbean in case he still didn't get his vibe to work, i had the same problem with the oscillator in my univibe clone, and i resolved putting 2 very high gain npn on q11 and q12, if i remember right bc549 (common EU NPN).

Ghandi · Post by **Ghandi** » 29 Dec 2011, 11:49

outtahear wrote:No parts numbers, but here's a set O' LDRs and incandescent lamp courtesy of Uncle Bob hisself.
Same ones he used on his vibes, got 'em 12 or so years ago.

I just started collecting parts for my vibe build, and somehow that bulb reminded me of something...
back in the days my grand dad used very similar looking lamps for his rc ship models.

Something like that:
http://www.voelkner.de/products/17501/S ... -20ma.html

cheers
ghandi

Ghandi · Post by **Ghandi** » 26 Feb 2012, 14:38

I just bought that mini 12v 40ma lamp and it looks very very similar to the mojo vibe bulb.
I'll let you know how it works when I've finished my vibe...

madbean · Post by **madbean** » 26 Feb 2012, 15:16

FWIW: the schematic I posted on pg1. is incorrect.

Ghandi · Post by **Ghandi** » 27 Feb 2012, 11:20

So... let us know the corrections, PLEASE!

and, I just made the UVICS pcb from geofex and noticed that you also have a Uni-Vibe board (Harbinger) in the pipeline...
what are the differences?

Thanks!
Ghandi

madbean · Post by **madbean** » 27 Feb 2012, 11:43

Ghandi wrote:So... let us know the corrections, PLEASE!

I don't know what the corrections are, unfortunately, because I've never gotten his oscillator scheme to work properly. I've gone back to it a couple of times but never sussed it out. But, you can mod the UVICS to the Mojo specs pretty easily. Add a switchable input JFET buffer, use the values from the Mojo vibe and you are most of the way there. Pinouts are going to be different for the transistors, though.

Ghandi · Post by **Ghandi** » 27 Feb 2012, 13:36

So you know that the schematic is wrong or do you think that it is wrong because you couldn't get your clone to work probably?

You still have the sweetsound mojo vibe, do ya?

madbean · Post by **madbean** » 27 Feb 2012, 15:02

I know the schematic is incorrect because I've breadboarded the oscillator as drawn and it doesn't work.

I still have it, but I won't be taking it apart again anytime soon. I'm pretty sure I can figure out what the problem area is without doing that anyway...just not a lot of time available to do that ATM.

jazzmaster · Post by **jazzmaster** » 27 Feb 2012, 15:12

Hello,

here are links to LDR/Bulb:

http://www.banzaimusic.com/Bulb-12V-20mA.html
Single LDR:
http://www.banzaimusic.com/Univibe-Phot ... -500k.html
And a matched set:
http://www.banzaimusic.com/Univibe-Upgrade-Kit.html

i used the 4 single LDR's in the other univibe clone with the 3 voice settings: Roger Mayer, Shin-Ei and forgot what the other was.
Dont know if the matchin is really needed, but i can think that you may get better pleasures. At the time id built my Vibe there
was no set avaiable. Sounds great also...

Ghandi · Post by **Ghandi** » 27 Feb 2012, 15:34

madbean wrote:I know the schematic is incorrect because I've breadboarded the oscillator as drawn and it doesn't work.

I still have it, but I won't be taking it apart again anytime soon. I'm pretty sure I can figure out what the problem area is without doing that anyway...just not a lot of time available to do that ATM.

Well, I think that the problem in your schematic is around the VTL5C3-2, the connections look a bit odd there...

monkeyxx · Post by **monkeyxx** » 23 May 2012, 06:38

if madbean makes a board for this I'll buy it in a heartbeat!

beedotman · Post by **beedotman** » 14 Sep 2012, 07:35

bump!
anybody have schematic for mojo?

beedotman · Post by **beedotman** » 15 Sep 2012, 17:07

Maybe somebody can check phase cap values in his Mojo and confirm if there are standard 15n/220n/470p/4,7n values?

beedotman · Post by **beedotman** » 18 Sep 2012, 13:19

Anybody?

mrkaploca · Post by **mrkaploca** » 27 Sep 2012, 11:58

yes they are.

beedotman · Post by **beedotman** » 28 Sep 2012, 07:34

mrkaploca wrote:yes they are.

Thanks!

Demystifying the MojoVibe [traced]