Neovibe Review (thanks RG!)

[LyleCaldwell]

I have long been looking for the perfect Uni-Vibe or clone for my needs.  I don't care about Robin Trower, and as much as I love Hendrix, I don't play Band of Gypsies style music.  I've been chasing Gilmour's Echoes and Dark Side Uni-Vibe sounds, particularly on Breathe.  That requires a deep slow throb without the low end "thud" most vibes make, and I wanted as little noise as possible.

And I've tried Dunlop Reissues, Fulltone Dejavibe 2 and Mini-Dejavibe 2, the Voodoo Lab Micro-Vibe, the Black Cat vibe, and lots of modelled Univibes.  About the only one I haven't tried is the Mojovibe, which I've heard great things about, but between the steep price and the purple color I never ordered one.

The Dunlops sounded pretty good but were noisy.  The Fulltones were quiet, but were voiced too bright for me (they must work great into a loud non-master volume Marshall though).  The Micro-Vibe sounded good but was kinda noisy and had a pronounced THUD to it.  The Black Cat was pretty good, but wasn't quite "there" enough for me - at that price "close enough" isn't.  The modelled vibes were just awful.  Odd that both Vox and Line 6 have pretty good Phase 90 models and usable Leslie models, but totally missed the boat when it comes to vibe. 

So, figuring it was worth the $50 or so in parts to try, I made a Neovibe using a GGG PCB and the GGG suggested parts.  When done, I was pretty happy with everything, but the max speed wasn't quite what I wanted (so I could play some of the Any Colour You Like warbly parts), the mix wasn't quite there (the intensity was either too much or not enough).  But it was very quiet and about as "almost there" as the much more expensive Black Cat.

So I did the 2.2K resistor speed mod, and got the max speed up where I want it.  Great.  I'd already done the unity gain mod.  Great.

Now my only problem was the not-quite perfect mix.  OK, replaced the two 100K resistors with 82K resistors and used a 50K linear pot.  Subtle, but effective.  Better.  But not quite right.

At this point I figured it was good enough, but it sure would be nice to have an LED pulsing in time with the LFO.  Read up on it, fiddled around, and found a way to get the LED pulsing with the LFO.  I found that you have to use very very little power or the LFO doesn't pulse strongly - a standard red or yellow LED stole too much power at the voltages where they'd light up dimly (I used a 100K pot before the anode of the LED).  So I tried an ultra bright blue LED, and with the pot all the way at 100K, the LED gets just enough power to visibly pulse.

But then I discovered that if I turned the 100K pot down just a bit, the LED was still in a good brightness range, but the mix and depth was affected.  In a very good sounding way.  Adding the 100K pot and LED in effect gave me a second bias control!

It's like having a fine tuner for the mix and depth knobs.  Some very slight adjustments of all three knobs, and there it was!  The perfect mix, the perfect depth, the perfect warble!  And so quiet! 

I'm extremely pleased.  Thanks so much, RG, for making this design available to us.

BTW, I removed the volume pot (not needed as the pedal is at unity compared to bypass - if you do this, don't forget to put a 100K resistor between the output and ground) and the vibrato switch, as I don't have a use for vibrato mode.

Pictures as soon as I put it in an enclosure and clips forthcoming.

[R.G.]

You're welcome - and thanks for the kind words.

I hear a lot about the ones that don't work. It's a downright pleasure to hear about one that does.

May you make loud, beautiful noises.

[Roobin]

Sounds really good! I myself am a huge Pink Floyd fan, esp. DSoTM. Sounds like my next project...
Did it come up to $50 or was it more or less. It's such a joy when you can tinker a pedal, knowing your not breaking some warranty - and laughing when people say they spent a load of dosh on some "custom" 'vibe. 

[LyleCaldwell]

Lemme check...  about $25 for parts/shipping at Mouser, $25 for the PCB from GGG, about $25 for the LDRs and dual ganged reverse pot and shipping from Small Bear, and about $2 for the lamp at Radio Shack.  Figure another $10-15 for an enclosure and it's around $92 total.  Still a deal.

[Bonzo]

Great job! I Can't wait to see the pics and hear those clips!!

[RedHouse]

Yeah, clips please!

[BDuguay]

This is very exciting news indeed. I've built the easyvibe and recently was given a dead Danelectro Chicken Salad that, once fixed, sounded pretty darn good too.
The Neovibe has been on my 'want to do list' for some time now and this is the kinda of report that should light a fire under this author's butt.
Clips and pics pleasey please.
B.

[markm]

I've been eyeing this project alot myself too.
Congratulations on your build, it's very rewarding isn't it?!!

[RedHouse]

Clips?

(bump)

[RaceDriver205]

Damn straight!
That neovibe is da gear! I could play mine for hours.
You think the sound cip at GGG is good? You'll love hearing it for real (i.e. built it now  ).

[DeeBug]

BTW, I removed the volume pot (not needed as the pedal is at unity compared to bypass - if you do this, don't forget to put a 100K resistor between the output and ground) and the vibrato switch, as I don't have a use for vibrato mode.

Hey Lyle, thanks for the great idea.  I'd like to get rid of anything that's not really necessary as I'm still doing some debugging on mine (It works but I have crackle).  I went ahead and took out the switch.  Next, I'd like to take out the volume pot.  I'm not sure where to put that 100K resistor though.  You mentioned "between output and ground".  So, would it work if I put the resistor between pads "N" and "L" on the board (as labeled in the layout diagram available at GGG)?  Pad "L" appears to be part of the ground trace, and "N" is the chorus (output?) pad.

[LyleCaldwell]

I don't have time to dig up the diagram right now, but the volume pot when on full is a 100K resistor between the middle lug and ground.  So that's where you put the 100k resistor - between the output of the volume pot and ground in the diagram.