Univibe (Neovibe) project

[richon]

Taking the Neovibe (from the original Univibe ) and modding it a little:














demos soon!!!

[richon]

DEMO:

http://www.youtube.com/watch?v=hAjbQ4rd7Xk

[John Lyons]

Nice work!

[jkokura]

sounds really good, pretty snazzy enclosure (big for my liking personally) - it looks like lots of fun to play too.

Makes me wanna build one. If only I didn't have a mountain of projects on my plate already!

jacob

[richon]

If only I didn't have a mountain of projects on my plate already!

well...

who doesn't     

[zeeman]

SOUNDS AWESOME!!!

It even sounds better then the one I built (I built mine around 12/13 years ago).

If you don't mind me asking, what brand/model photocells did you use?

zeeman

[WhenBoredomPeaks]

Slightly off, but what happens with the clean signal in a vibe type effect? I almost perceive it as a slight tremolo but there's got to be more to it. If someone could describe it in a few words (i don't need the actual physics and stuff of it) i would be happy.

[richon]

If you don't mind me asking, what brand/model photocells did you use?

zeeman

i really don't know

in my country some electronics part you buy don't get any brand/model...  it was just and old electronic parts store in town.

they worked better than some "better branded" of a better electronic parts store

[zeeman]

If you don't mind me asking, what brand/model photocells did you use?

zeeman

i really don't know

in my country some electronics part you buy don't get any brand/model...  it was just and old electronic parts store in town.

they worked better than some "better branded" of a better electronic parts store

Would you happen to know the resistance range of the photocells from dark to light?

Thanks.

zeeman

[richon]

i'm sorry but I can't measure them now


is there a comon value to have a GOOD vibe sound?

[WhenBoredomPeaks]

i'm sorry but I can't measure them now


is there a comon value to have a GOOD vibe sound?

No (at least i don't know any) but since yours sounds really good, it would be nice to know the values of your LDR, maybe your values could be the next DIY standard or something.

[SteveB]

I agree, yours sounds very, very good. It must be the the perfect blend of LDR's & bulb. Did you modify anything since your demo in 2007?

[zeeman]

richon,

I agree, yours sounds very, very good.

Again, +1 - your vibe definitely has the MOJO.

To answer your question...

is there a comon value to have a GOOD vibe sound?

Yeah, what ever values you are using.

The other day, I whipped out the (very) old documentation that I have on my Uni/Neo-vibe that I built way back when.

What I did not mention in my first post was that this was one of the first "Neovibe" PCBs from RG. The PCB does not have a version on it but I also have image for PCB version 1.21 and mine precedes that one.

From that old documentation that I have (and I am quoting RG)...

I checked through a lot of catalogs and directories and never found a photocell with a number corresponding to the note on the original schematic. An interested friend who had access to a Univibe was kind enough to measure the resistance swing of the photocells at 50K to 250K. I wound up making a version with LED's ad phototransitors first, then retrofitting to available incandescent bulbs and photocells per the "original". The 50K-to250K range did not give me the good swing by ear, so I increased the range to 10K to 400K in my prototype.

Currently, I could only find three (3) documents on RG's website that reference the Uni/Neo-vibe. Below are the links to the three (3) documents.

http://www.geofex.com/article_folders/univibe/univtech.htm
http://www.geofex.com/Article_Folders/univibe/vibeupdate.pdf
http://www.geofex.com/FX_images/vibeschm.pdf

None of the above have the quote that I found in my old documentation. There could be another Uni/Neo-vibe document on RG's website, but I could not find one.

Thinking back, after I built my Uni/Neo-vibe, I never really went back and properly tweaked it so I think I will start there.

By the way, what transistors did you use? I built mine using 2N5210 (per the old build instructions) for all of the transistors. I did have John Lyons make me a couple of Forum Vibe PCBs but right now I don't have the time to start a project of that magnitude from scratch since I have a couple of other projects that I want/need to work on.

Thanks.

zeeman

[petemoore]

so I increased the range to 10K to 400K in my prototype.
  Where the signal is inclined to path is pretty obvious when looking at the LDR positions in the phase stages, anything over say 500k at the LDR position is making the other path look very much easier to the AC signal.
  I made an EZ-Vibe using RS Photocells.
  I had no trouble finding the medium and large sized ones that went to <10k.
  They all went well over 470k [>2 meg common].
  I'm not sure what the sound'd be like with R-cells ranging below say 4k7 under light conditions.
  [the Small resistance being where it counts and the cells might have trouble getting that low].
  As far as R-sweep speed, in the old units there was a 'slow bulb', so what was slower the bulb or the LDR's? [I vote bulb].
  I just did a quick 'what shows up' under normal light/easy dark [it's the low resistance/lighted conditions anyway, sorta dark goes way up over 1meg pretty easy. Scaled by their own numbers, the ones that read low resistance under 'light' went in.
  The other way to really tell of course is test-measure some data sheet claims on the 'fancy' photocells...compare to RS specs, then see what each type does in the Vibe circuit.
  Testing the types of cells of course on 1 common circuit.
  Also worth mentioning [or of relevant importance] is how well they match one another as far as R-sweep related to light condition.
  This, of course, can [and probably should, if you're worried about what LDR and particular sweep X/y qualities] be diddled with, in many ways.
   

[richon]

finnaly they are some values:


from 20K  or  30K to 2M to 2,1M     (i've seen some with more OHMS in dark also)

but i think that besides the value it gets its how fast it change his value from dark to light, right?

[Kitarist]

Just want to ask how did you add the white letters?

[bt2513]

Slightly off, but what happens with the clean signal in a vibe type effect? I almost perceive it as a slight tremolo but there's got to be more to it. If someone could describe it in a few words (i don't need the actual physics and stuff of it) i would be happy.

It actually gets blended with the effected signal but the phase is different IRRC.  I have a trimpot in the place of R35 (or R36?) on mine that controls the blend level/phasing... there is a sweet spot that produces the deepest phasing possible for the richest effect.  The Neovibe functions more like a phase shifter than a tremelo... in fact, there are some "Phase 100" mods available for it out there I believe..

[JRM]

I'm amazed! Congratulations!