UVICS - Univibe In a Crybaby Shell

[RedHouse]

I was referring to the direct quote below that I believe you wrote in the forum vibe stuff that someone emailed to me:

It isn't a new design, unless you tend to call reworking a PCB layout designing (which I don't),

I kind of agree with you on that. I think of design as a much more enlightened and demanding activity. But I don't much care what we call PCB redesign. Some PCB work is closer to crosswords and doodling, some takes attention and focus. Shrug. I'm good with calling PCB work design or not, whichever you'd prefer. You pick, I'll call it that. How much fairer could that be?  

I totally agree your UVICS project as with my own vibe's are definately not "designs" but simply implementations of ideas from various sources.

Did you read the old PDF's or visit the new webpages?

Speaking of incorporating mods, reviewing the coolness in the UVICS:

• Next generation Neovibe, complete with v-reg mod
• JC's bias offset mod (wins best mod award IMHO)
• Both my darlington mods (LFO and Q10), and my 1M input bias mod
• Bob Sweet's single-pot speed ctrl (currently gone, but you said might be back)
• JC's speed LED mod (not there yet, but you said you're working on it)
• Resley-Tone/Rands/RM Voodoo Vibe Q11 addition (UVICS Q14)
• Fits in a wah-shell

You're amazing RG, goodonya!.
(Scottish phrase, means "atta boy")

A few more things you can add, how about the RM Tremolo mod lots of people like that, and my "Multi-Vibe" mod (or a flavor thereof) that's really popular too, and of course JC's mU front end option which brings better fidelity to the vibe.

[Davefx]

Hello hello.. I'm chiming in a bit late I realize, but that's my vid that Brad linked and  I will clarify upon what i did.. I did what JC Maillet had posted a few years ago.. It was a super bright blue INLINE with the B+ going to the bulb, with a 500 ohm trimmer in parallel with the LED. That's it. Works great:)  Just play with the trimmer till you have the desired result.  Or if you have it figured out then, what ever works is what i say

Dave

[R.G.]

Hello hello.. I'm chiming in a bit late I realize, but that's my vid that Brad linked and  I will clarify upon what i did.. I did what JC Maillet had posted a few years ago.. It was a super bright blue INLINE with the B+ going to the bulb, with a 500 ohm trimmer in parallel with the LED. That's it. Works great:)  Just play with the trimmer till you have the desired result.  Or if you have it figured out then, what ever works is what i say

That's what I was suggesting earlier, and it's the solution I have in the currently-online layout. It's probably the simplest way to go about it. As I noted, the bulb currents are almost right for an LED, so with a little work, it can be made happy in that environment.

I have a scheme worked up for turning the LED off when the thing is bypassed. You use an LED/phototransistor module, which can come in DIP-6 or DIP-4 packages and have the bypass switch put current into the LED. The photo transistor is hooked across the LED and the same bulb current still goes in, but the LED is "muted". I'm trying to see if it can be stuffed into the layout. Might need to be out with the indicator LED.

[Eb7+9]

As I noted, the bulb currents are almost right for an LED, so with a little work, it can be made happy in that environment.

a current of 0.1mA is enough to light it up an LED moderately ... the current through the bulb can be anywhere around 10~40mA (or more) at its peak depending on bulb filament ... that's a 100:1 (or more) ratio ...

the resistor/trimmer across the LED acts as a current divider // a basic concept in electronics

http://en.wikipedia.org/wiki/Current_divider

[R.G.]

a current of 0.1mA is enough to light it up an LED moderately ... the current through the bulb can be anywhere around 10~40mA (or more) at its peak depending on bulb filament ... that's a 100:1 (or more) ratio ...
the resistor/trimmer across the LED acts as a current divider // a basic concept in electronics

Yes. LEDs need currents on the order of 1ma to light up well, and they withstand 100ma pulses in multiplexing. As I noted, the current in the bulb is nearly the right range, and can be made to work with some effort, perhaps shunting it with other things, perhaps a resistor. Shunting with resistors is indeed an old, old technique. It predates either of us, eh? Is there a subtlety lurking there?

[R.G.]

On a more interesting note, I think the transistor-output optoisolator can be made to work for letting the pulsing LED work as an effect/bypass indicator, and there may be room to put it on the PCB. Maybe. The mounting holes cramp things up a bit.

It works like this: the opto has an LED and a phototransistor. Run current through the LED, and the phototransistor turns on. The phototransistor is connected in parallel across the LED, and when turned on it ... hmmm, yes - acts like a current divider.   

Current divider. Current divider.  Cuuurrrent Deeevider. Catchy name. I like it.

Well, anyway, it so divides the current that it divides it more and more for itself until the voltage across the LED falls under its ignition voltage, at which time our poor LED is starved for electrons and goes dark, sulking in its room because it's better to curse the darkness than to light even a single candle, right?    The electrons still go through the bulb, merely diverted around the LED.

More to the point, the phototransistor is isolated from the LED, and doesn't care what gyrations in voltage the lamp and driver are doing to it. So a current from anywhere into the optoisolator LED turns off the indicator LED, and no current lets the indicator LED's little light shine. A suitably equipped bypass switch could provide said current turning on the phototransistor and off the LED in series with the bulb.

Note that you can also work it backwards, probably. If you did a good Current Divider (that is a resistor) in parallel with it, you could put the optoisolator's LED in series with the bulb, and use the opto's photo transistor to turn an external LED on and off in time with the lamp current. The brightness ratio issues which come up every time you use an LED would still be with you, but with appropriate use of current dividers on every one of them, you could adjust the brightness to be what you want. Probably.

But I'm guessing that someone else somewhere else long ago and far away in another galaxy has already done it.

[Brymus]

My thought was a seperate driver circuit running off the same LFO.
That way I could run two LEDs (for more light even,yes I want it ti be very noticable) and trim them to turn off and on
more intensely,than the bulb which just glows on off..

[Davefx]

 Hey Brymus, sounds like you want what I'm going for on my next one.  I have the makings for one more wah/vibe which I plan on being an over the top "light show spectacle", lol. The one in the vid features one of the excellent boards that Brad made into one of my spare cry baby shells. Also, you may have noticed the 2 LEDs and the rock back bypass, that was also a JC design that I sort of guinea pigged with him over the last year, and I love it!  I wanted the "rock back" like the original vibe's cancel, but with true bypass.  The new one, I'll be painting with an expensive PPG metallic red, with white stenciled graphics (I have a complete PPG mix system at work so why not?). 1/4" Lexan for the bottom plate which I will have several bright leds indicators, (stop/go/speed ind, etc.) somehow directed into it (yet to figure that one out! ) I want it to be TOTALLY over the top, LOL! And I'm sure it wouldn't be everyone's cup of tea, but I GOTTA do it man, as it will be a one-off for me only!
Also, a special opto speed contoller circuit will be utilized instead of the standard 100k dual..   FUN FUN!!!!

Dave

[RedHouse]

Hey Brymus, sounds like you want what I'm going for on my next one.  I have the makings for one more wah/vibe which I plan on being an over the top "light show spectacle", lol. The one in the vid features one of the excellent boards that Brad made into one of my spare cry baby shells. Also, you may have noticed the 2 LEDs and the rock back bypass, that was also a JC design that I sort of guinea pigged with him over the last year, and I love it!  I wanted the "rock back" like the original vibe's cancel, but with true bypass.  The new one, I'll be painting with an expensive PPG metallic red, with white stenciled graphics (I have a complete PPG mix system at work so why not?). 1/4" Lexan for the bottom plate which I will have several bright leds indicators, (stop/go/speed ind, etc.) somehow directed into it (yet to figure that one out! ) I want it to be TOTALLY over the top, LOL! And I'm sure it wouldn't be everyone's cup of tea, but I GOTTA do it man, as it will be a one-off for me only!
Also, a special opto speed contoller circuit will be utilized instead of the standard 100k dual..   FUN FUN!!!!

Dave

I too prefer utilizing a heel switch option Dave.

In my case I've leaned toward the old style cancel switch and just use the stock wah-switch for true bypass and of course  tailoring the speed range into that physical area of pedal travel.





UVICS builders will not be able to do it like this of course because the area needed for these mods is used up the PCB and it's power section and stuff.

Feedback from my peeps (live/stage) indicates more liking toward using "cancel" during a song as it keeps the tone of the pedal during the song (that 3-transistor vibe preamp does have a "tone" to it) and then they use the normal true-bypass switch to remove the vibe from the chain for other songs.
(switching between songs)

On my (full retail product) Vibe-Baby pedals I use a dual color LED (Red/Green) for indication of effect in (On) and out (Off), it's Red for Vibrato mode, Green for Chorus mode. I don;t usually use either (JC or Bob Sweet) speed indicator as I prefer the user to dial in the speed "by ear".

BTW how's that new JC bypass board working out? is it ready for prime time? I'd like to try that myself one of these days.

EDIT:
Hey! The site pages for the Forum vibe look sharp Brad!
Nice work on those. Comprehensive!  

Thanks John, it was definately worth the effort. Thanks also to those who helped debug the pages, which reminds me, if ya see errors please send an email and I can focus on corrections.

[Brymus]

As we take a break from our Vibebaby infomercial... 

My thought was a seperate driver circuit running off the same LFO.
That way I could run two LEDs (for more light even,yes I want it ti be very noticable) and trim them to turn off and on
more intensely,than the bulb which just glows on off..

Does anyone have any thoughts if my idea will work ?
I would just put it on a little board.
Would just using 2 x 4k7 to the two driver circuits (one to each) work OK ?

[R.G.]

Does anyone have any thoughts if my idea will work ?
I would just put it on a little board.
Would just using 2 x 4k7 to the two driver circuits (one to each) work OK ?

Yes, it will work - or at least can be made to work. I'm sorry - I didn't realize you were waiting for a response.

I worry about loading on the emitter of the LFO. Simply replicating the existing driver circuit doubles the loading on the emitter.

I thought about a replicated driver, a normal and darlington emitter follower from Q12 emitter, and a couple of others as well as putting the LED in series with the bulb. The series with the bulb was the least added circuitry, I thought.

But it works as well to tap off the full LFO swing at the wire pad that connects to the joined lugs of the speed pot to get LFO out. This is always full size (which varies with speed I think) but it would drive a high impedance buffer to run some LEDs.

Going back to your post:

My thought was a seperate driver circuit running off the same LFO.
That way I could run two LEDs (for more light even,yes I want it ti be very noticable) and trim them to turn off and on  more intensely,than the bulb which just glows on off..

Did you want them to turn on and off more abruptly? More of on/off and not fade up/down?

[R.G.]

OK, did some tinkering.

I think this works. Tie one end of a 100K to the emitter of Q12. Tie the other end to the base of an MPSA13 or a discrete darlington. Emitter of the darlington goes to ground through a 2.2K resistor. LEDs are stacked in series from the collectors of Q11/Q12 (power supply, that is) to the collector of the added darlington. You can use several LEDs in series until you run out of voltage. Two blues and more greens and reds should be possible.

The emitter resistor for the darlington sets the current swing and brightness swing. It goes to essentially zero, and up to about 5ma with the 2.2K resistor Bigger resistor is lower current. All the LEDs use the same current, so it's easy on the power supply. If you want to use the LEDs as bypass status indicators, short the base of the darlington to ground when the effect is bypassed. That's what the 100K in series with the base is for, to let you short the base to turn them off.

I'd do this rather than a whole new driver. It amounts to a driver circuit, but pre-biased and pre-set up to work for nominal LED currents.

[R.G.]

For those of you who noted the eight-stage vibe, I did a little walk down memory lane in the archives today. I found three separate stages of the design work in various stages of completion, and also .... the first actual prototype! It survived moving house twice.

The file date on the layout that looks most promising to resurrect is from 1996.   

It will take some work. It took importing through three level of newer PCB layout software to get it to where I could see it.

I also found a slew of other interesting stuff from the era when I was working on the 'vibe most. It was a veritable rainbow of sound. 

[RedHouse]

As we take a break from our Vibebaby infomercial... 

Sorry Brymus.

[Brymus]

OK, did some tinkering.

I think this works. Tie one end of a 100K to the emitter of Q12. Tie the other end to the base of an MPSA13 or a discrete darlington. Emitter of the darlington goes to ground through a 2.2K resistor. LEDs are stacked in series from the collectors of Q11/Q12 (power supply, that is) to the collector of the added darlington. You can use several LEDs in series until you run out of voltage. Two blues and more greens and reds should be possible.

The emitter resistor for the darlington sets the current swing and brightness swing. It goes to essentially zero, and up to about 5ma with the 2.2K resistor Bigger resistor is lower current. All the LEDs use the same current, so it's easy on the power supply. If you want to use the LEDs as bypass status indicators, short the base of the darlington to ground when the effect is bypassed. That's what the 100K in series with the base is for, to let you short the base to turn them off.

I'd do this rather than a whole new driver. It amounts to a driver circuit, but pre-biased and pre-set up to work for nominal LED currents.

OK thank you RG I will give this a try !!

I can't wait to see what your modder/omni vibe turns out looking like.

[RedHouse]

OK, did some tinkering.

I think this works. Tie one end of a 100K to the emitter of Q12. Tie the other end to the base of an MPSA13 or a discrete darlington. Emitter of the darlington goes to ground through a 2.2K resistor. LEDs are stacked in series from the collectors of Q11/Q12 (power supply, that is) to the collector of the added darlington. You can use several LEDs in series until you run out of voltage. Two blues and more greens and reds should be possible.

The emitter resistor for the darlington sets the current swing and brightness swing. It goes to essentially zero, and up to about 5ma with the 2.2K resistor Bigger resistor is lower current. All the LEDs use the same current, so it's easy on the power supply. If you want to use the LEDs as bypass status indicators, short the base of the darlington to ground when the effect is bypassed. That's what the 100K in series with the base is for, to let you short the base to turn them off.

I'd do this rather than a whole new driver. It amounts to a driver circuit, but pre-biased and pre-set up to work for nominal LED currents.

That's similar to the Fulltone Mini Deja Vibe.

[Brymus]

As we take a break from our Vibebaby infomercial... 

Sorry Brymus.

Brad you have some good ideas,and lots of knowledge to give advice from,thats always appreciated.
Perhaps presenting it in a way that doesnt seem so competitive,or self promoting would be better for the purposes of this thread.

[RedHouse]

As we take a break from our Vibebaby infomercial... 

Sorry Brymus.

Brad you have some good ideas,and lots of knowledge to give advice from,thats always appreciated.
Perhaps presenting it in a way that doesnt seem so competitive,or self promoting would be better for the purposes of this thread.

I agreee. Are there some classes I can take?

[Brymus]

For those interested in "vibes".
I found the schematics to Roger Mayer's vibe at the "other " forum.
Both the discreet and IC version are there.
He has the tremolo mod ,and uses 2.2 uf caps instead of 1uf.
I know eventually I am gonna have to breadboard a test vibe to try these minor changes.

I think the "ubervibe" uses 4 regenerative feedback filters,not four variable tone caps.
The "tubevibe" uses an LFO that you can change waveforms on,in conjunction with switchable tone caps on a dipswitch.

[Brymus]

As we take a break from our Vibebaby infomercial... 

Sorry Brymus.

Brad you have some good ideas,and lots of knowledge to give advice from,thats always appreciated.
Perhaps presenting it in a way that doesnt seem so competitive,or self promoting would be better for the purposes of this thread.

I agreee. Are there some classes I can take?

Yes but my son's daycare has an age limit.
You might be a little too old