Vibrato Pedal

[fingersoccer]

Hello everyone.

I'm having a hard time finding a prefabbed vibrato PCB (a pitch-bending vibrato, not an amplitude-modulating tremolo). Seems like it's pretty basic effect but nobody seems to carry them. Any leads I'm missing?

Thanks.

[CynicalMan]

Most choruses are just vibratos with some dry signal mixed in. Get a chorus PCB and remove the dry mix. Better yet, put in a switch to choose between chorus and vibrato.

[nexekho]

I don't know for sure but I'm thinking you could probably do it with a standard echo IC like the PT2399 if you're willing to put up with latency, using a LFO that goes above and below 100% speed, but I can't be certain.  To do it latency free probably needs DSP.

EDIT: Found one someone did with a PT2399, but they're using a microcontroller as a LFO.
http://soniccrayon.blogspot.com/2009/08/vibrato-build-more-hollow-earth-stuff.html

[asatbluesboy]

Most choruses are just vibratos with some dry signal mixed in. Get a chorus PCB and remove the dry mix.

The Small Clone is perfect for this. The Small Stone/ROSS Phaser have a sound of their own, sort of a middle ground between pitch bending and amplitude modulation. It's hard to explain, but it's beautiful.

[Mark Hammer]

Most choruses are just vibratos with some dry signal mixed in. Get a chorus PCB and remove the dry mix.

This is correct, however there are a few things to take into account:

1) The waveform that "works" for chorus may be sub-optimal for vibrato.  One of the things that endears the Boss CE-1 to so many people is that it uses a different waveform for vibrato than it does for chorus.

2) Since the "effect" is cancelled when the modulated-delay signal is removed, the preponderance of reasonably-priced chorus pedals (and I'm excluding boutique pedals here) will use a single FET to lift the wet signal for what they call "bypass".  The dry signal never changes.  So, if you attempt to synthesize vibrato from a commercial chorus (or even phaser) pedal by lifting the dry signal, there is a pretty darn good chance that when you step on the bypass switch, you aren't going to hear anything in bypass mode.  Using "dry-lift" to score a cheap vibrato option will work best if the pedal uses true bypass such that your mod has no effect on what goes through in bypass mode.  There ARE ways to rig up vibrato OR clean-bypass, using FETs and the existing electronic switching circuitry, but I'll leave those details aside for the moment.

[nocentelli]

It seems a bit inefficient to build a more complex chorus unit, then modify to simplify the effect down to vibrato only...

I know you're after a prefab pcb board, but this vibrato is sounds great and is dead simple to build on vero - The range is speed range is a little limited, but perfectly suited to the effect, and it would only cost a couple of quid in parts:

[CynicalMan]

Most choruses are just vibratos with some dry signal mixed in. Get a chorus PCB and remove the dry mix.

This is correct, however there are a few things to take into account:

1) The waveform that "works" for chorus may be sub-optimal for vibrato.  One of the things that endears the Boss CE-1 to so many people is that it uses a different waveform for vibrato than it does for chorus.

True, although the choruses that I've tried out with this mod have all turned out fine.

fingersoccer, if you choose to use a chorus PCB, let us know, and we can help you to mod the LFO if necessary

2) Since the "effect" is cancelled when the modulated-delay signal is removed, the preponderance of reasonably-priced chorus pedals (and I'm excluding boutique pedals here) will use a single FET to lift the wet signal for what they call "bypass".  The dry signal never changes.  So, if you attempt to synthesize vibrato from a commercial chorus (or even phaser) pedal by lifting the dry signal, there is a pretty darn good chance that when you step on the bypass switch, you aren't going to hear anything in bypass mode.  Using "dry-lift" to score a cheap vibrato option will work best if the pedal uses true bypass such that your mod has no effect on what goes through in bypass mode.  There ARE ways to rig up vibrato OR clean-bypass, using FETs and the existing electronic switching circuitry, but I'll leave those details aside for the moment.

Yes, but the OP wantes a PCB for a DIY vibrato (or chorus), and I haven't ever seen one that doesn't use 3PDT switching.

It seems a bit inefficient to build a more complex chorus unit, then modify to simplify the effect down to vibrato only...

It seems more inefficient to me to build a vibrato that could easily be a chorus with a few more parts! The differences are the LFO (as Mark pointed out) and the dry mix, but they're similar enough that you might as well build them into one pedal for a few bucks more than vibrato alone.

[fingersoccer]

Great replies.

That Magnavibe board looks great, nocentelli. I've heard clips of this pedal and it has a wonderful sound.
I was planning on building a chorus pedal as well, so I agree with CynicalMan in that I may as well buy a few extra parts to be able to switch between the two. Is this just a simple matter of putting together a chorus pedal (maybe the Small Stone, as per asatbluesboy's suggestion) and modding in a switch that cuts out the dry signal?

Thanks.

[nocentelli]

It seems more inefficient to me to build a vibrato that could easily be a chorus with a few more parts! The differences are the LFO (as Mark pointed out) and the dry mix, but they're similar enough that you might as well build them into one pedal for a few bucks more than vibrato alone.

True, IF you like chorus (I hate it), plus the OP was after a vibrato.

[B Tremblay]

John Lyons was selling ready-to-solder PCBs for the Tri-Vibe, but I am unable to find a link on his site.

[fingersoccer]

The Tri-Vibe looks pretty sweet. Looks like boards can be found here: http://www.basicaudio.net/runoffgroove-boards.html
Any other leads?

Thanks thanks thanks!

[Mark Hammer]

BYOC carries a Vibrato pedal project, based on the old Boss VB-2.  You can probably buy a board from them, or the whole project if that strikes your fancy.

Behringer makes a VB-2 clone, though I have to say that when I tried it I was not knocked out by it.  I should qualify that by specifying that I found the depth-swell (i.e, delayed vibrato onset) a little "off" for my tastes.  I think I needed a different ramp-up function, either log or anti-log or something.

Quite frankly, I still think it makes more sense to sate your DIY thirst by getting a cheap chorus, like a $15 FAB chorus from Guitar Center, mod and rehouse it.  Stick one of those in a 1590BB with a latching stompswitch on one side and a momentary on the other, make the dry-lift selectable with a toggle, and you've got yourself a nice useful pedal.