Univibes clones. Layouts questions

[Gearbuilder]

Hi
I'm curious about some differences beetween  Univibes clones and the original
There's three mains schematics on the net about Univibe
-One from geofex
-One from JC mallet
and one from John Hollis ;what's about the JC mallet layout?Is it the best sounding or easiest to tweak the vibe?
Does  anybody here could help me ?
Bruno

[petemoore]

But only 'know' about the EZ Vibe cause I built one and used it tonight.
 I love it. I think it sounds great.
 It looks the easiest to build to me, and runs on 1 nine volt supply.
 I used TL082's but it would fade. Following a suggestion I put in 062's and that did it/ almost/ at my buddies house it fades again.
 I have the very simple LM317  voltage regulator built and ready to go in there, I think I'm the only one that has exped these PS problems.
 I used opto stuff from NTE guy's shelf [Philcap I believe] LDR's and RS LED's...but I plan to try some higher sped LDR's...it gets a good 'fold' er whatever they call that overlap phaze sound [Jimi/Robin] thing pretty deep as it is.

[R.G.]

One from geofex

This is exactly the schematic of the original, but substituting a voltage regulator for the passive power supply of the original for lower hum.

One from JC mallet

I haven't checked in quite a while, but last I looked this was the original circuit, but the layout was for a hand-drawn, no-drill PCB. Same schematic, but using the original power supply.

These two should sound the same, given good attention to detail in building.

one from John Hollis

This is a build in the spirit of the original, not the original circuit. Some people are very pleased with it. You may or may not be able to hear a difference in tone.

what's about the JC mallet layout?Is it the best sounding or easiest to tweak the vibe?

Since it's the same circuit as the Geofex layout, it's going to sound the same, given equal parts and care in building. I can't speak to how hard it is to tweak. I'm most familiar with my layout (it's been available since about 1994, so it's got a lot of history now) so I think it's the best base to work from, but that's just me. YMMV.

[Jason D]

RG,

I was looking at the schematics from a link listed in a previous post about Univibes. This PCB looks very much like your layout. Is it?

http://www.harpamps.com/schematics/unvbachk.pdf

[moosapotamus]

I built jc's version. Sounds great. But, I think the specs of the LDRs might make a big difference in how it ends up sounding.

Haven't tried any others. But, my guess is that R.G.'s or Hollis' version (ezvibe) might give better results with less concern for parts' specifications.

~ Charlie

[EdJ]

I am making the JC Maillet one because VIN chose that one and we agreed on building and tweeking it together.
To be honest i think i would choose R.G.`s because it looks more clear to me but we will see;if it doesn`t work out for some reason we can always go to that.
Greetings,Ed

[R.G.]

I was looking at the schematics from a link listed in a previous post about Univibes. This PCB looks very much like your layout. Is it?

You've found a bit of history. That is, indeed, a very early edition of my univibe layout. That one is from the early 90's.

The set of schematics it's from is the set from the first internet effects site and schematic repository. That was put up by Jaime Heilman while he was in college. He and I contributed about half the schemos each.

[dr]

....I built the Neovibe from JD's site which I think is a redraw of originally RG's layout-it is EXCELLENT!...I sent a sound file to JD;I may send one here if I figure out how to attach it in the forum...I tried the first photocells I could find (in one of those cheap night lights)..what really worked for me was adding length to the leads and putting them farther away from the light source,sort of tweaking which way they bent to get the best sound then replacing the homemade light cover (I had an old capacitor can and cleaned it out and wired it to the two holes provided on the board)I don't really feel the "proper"photocells are necessary;I tried three different sets and sizes and variances of resistances;its just that I left the cheap ones in it....(meaning the night light ones..)I matched a pair of resistors for the 100k notch pair (a flaky pot caused oscillations that were quite objectionable and squealing!)

[V!N]

I am making the JC Maillet one because VIN chose that one and we agreed on building and tweeking it together.
To be honest i think i would choose R.G.`s because it looks more clear to me but we will see;if it doesn`t work out for some reason we can always go to that.
Greetings,Ed

I also find it a bit hard to read the rough handdrawn thingies, but JC sure has some interesting mods for it.

[Gearbuilder]

Hi,
Thanks R.G. for your reply and the others too,i'm going to do a 2nd  Neovibe clone . As you say ,the more important is to match the cells and find a bulb,i've read many about univibe and i've bought many LDR's but
i'm not very  happy with my first clone :compared to my old Small-Stone or my  Ibanez Phase-tone it was not so deep and creamy .
The sound is quite ok but the cells seem to be very different from the original.I think they are  the magical parts of the univibe ,does anybody here have  the real specs ?I've tried 10 to 50K ,20 to 150k ;small ones ,bigs ones and some others ,the phasing effect never seems to be well centered ,with a set the high frequencies are well cancelled,with the other set the low frequencies are well cancelled .
I've seen on RS components some LDR's ,but i'm not sure they are right for the Univibe ,who has tried them(the little ones )
Bruno

[Gearbuilder]

Hi,
Thanks R.G. for your reply and the others too,i'm going to do a 2nd  Neovibe clone . As you say ,the more important is to match the cells and find a bulb,i've read many about univibe and i've bought many LDR's but
i'm not very  happy with my first clone :compared to my old Small-Stone or my  Ibanez Phase-tone it was not so deep and creamy .
The sound is quite ok but the cells seem to be very different from the original.I think they are  the magical parts of the univibe ,does anybody here have  the real specs ?I've tried 10 to 50K ,20 to 150k ;small ones ,bigs ones and some others ,the phasing effect never seems to be well centered ,with a set the high frequencies are well cancelled,with the other set the low frequencies are well cancelled .
I've seen on RS components some LDR's ,but i'm not sure they are right for the Univibe ,who has tried them(the little ones )
Bruno

[dr]

....if you aren't happy with the ldr's you have in it,try lengthening the leads of the ones you have in the clone already...it made a world of difference getting the sound I was after!! I found moving them a bit further away from the light source theres an area that does wonders for the sound!....(what I mean is,when I moved them away from the light,they sounded better-I also tweaked the bias for the bulb a bit lower than usual,but panel mounted the bias pot)

[Gearbuilder]

Hi ,

Thank you dr,i'm going to try your mod, what is  the distance beetween the cells and the bulb?I've done a cover with aluminium sheet it's better than the plastic can or the old capacitor can for the moment.My cells are at the same distance of the board than the bulb and placed // with the top of the aluminium case.I'm going to try to short them a little,
Bruno

[dr]

....I made the legs on the ldr's about 1 and 1 half inches long;placed the bulb slightly 1 half inch below the ldr's,and bent the ldr's at various angles towards the bulb,but not directly facing it.....and I ended up soldering in two 100k resistors instead of using a pot to match each side....I think the ldr's don't matter,because all the ldr's I used each time were different sets,and eventually all of them could be made to sound good depending on how much or how little light fell upon them.I decided to use the cheap night-light ldr's in the final version just to have something to show my friends that the answer to the "ldr problem" is not so exotic as your local Odd Lots store........