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Univibe

Started by madbean, September 07, 2010, 12:39:37 AM

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Davefx


madbean

Quote from: Davefx on November 05, 2010, 01:05:40 AM
Madbean... Do you recall what voltages the Mojo runs at? I know he charge pumped it to 18v, is that correct?
I'm curious if the LFO and audio are operating from the same B+ levels... Normally the LFO runs at a higher voltage because it's unregulated as in the case of the Neo...  But what I have found, as was recommended from JC Maillet, the original vibe actually ran on 24-25v and I have to say it makes a HELL of a difference when I jacked my Neo up from 15v. Dave

The entire thing runs off the charge pump voltage save for the last transistor of the phase stages. It appears to run off 9v. Why, I don't know. Anyway, some charge pumps can take up to a 12v input, so it's possible to get close to 24v (probably 22.x) esp. if using 1n5817s instead of 1n4001 (lower voltage drop). I will get some voltage readings when I get back as I need to debug my prototype build of the Mojo, anyway.

Davefx

Ok, I wanted to turn you on to the stuff I've been doing with my search for the "Hendrix warble" . First, I think my favorite sound of the Sweet vibes was this clip of his first "Ultra Vibe".  http://www.sweetsound.com/Audio/Vibedemo1.mp3

  It really demos how close the man nailed the sweep.

But, in my case, over a year ago, I completed a Neovibe. I made the little copper sheeting lightshield with aluminum foil, Smallbear NSL7532 cells, flush pointing up on the board, and a RS 1.5v 25ma bulb.  I got nothing but thump and no swirl no matter where I adjusted the bias trimmer.  In tears, I gave up and the project was benched until last July, when I discovered the works and research of JC Maillet and his Viva-Analog company. You may or may not have heard of him, if you haven't, I must encourage you to check out his site, which I will link in a moment. A brilliant, generous, and talented dude for sure.

  Anyway, I ordered one of his boards, became a member of his private forum, and I was a total sponge for knowledge :) He had posted several of his performance mods for the vibe, and all I can say is, that they are what i needed!

His bias offset mod being one of the most significant, as it allows you additional tweak ability to use any different bulb and cells to get just about any warble one would desire.  Now back to mine, I ordered a new set of cells, and a 12v 40ma bi-pin bulb (7371 Chi. Mini.)the higher current bulb got me even closer, and I this time pointed the cells directly to the bulb, and with the bias offset mod in place I became ALMOST there! Now the reason I asked you what the voltages were on the Mojo was because I was just about ready to replace the 15v reg. with a 24v.  Well I did, and BINGO!  I'm pleased with my results and so if you would like to hear it, I give you the link.

Dave....       http://www.viva-analog.com/

FuzzMonkey

Bring on the Vibe!  ;D

Ang3lus

A univibe would be awesome