UVICS - Univibe In a Crybaby Shell

[R.G.]

What I meant was, how do I face the diodes (what type, how many) for making the 12V reg a 15 V reg ?

Oh. Yeah, that.

You put them in series with the ground pin of the regulator, anode to regulator and cathode toward ground. Lift the ground pin of the regulator and solder the diode string between it and ground, elevating the voltage of the regulator ground pin.

It'll be a little clumsy, because you'll probably need four in series. I've done this with one and two diodes, not with four, before. I think it will work. It messes up any precision regulation, but that's not necessary for this.

[RedHouse]

 

You can also just add a resistor, ala; LM317 (see data sheet) which takes up less space, and a 10uF electrolytic capacitor, it'll be rock solid. You can also add the 10uF cap across a diode stack.

A vibe doesn't have to run at exactly 15v as RG said earlier, but is a great place to be. I've found you can run them even up around 24v which gets more headroom but is not necessary, 15v does quite fine.

[R.G.]

regarding the Dunlop cry baby rack-n-pinion system and it's geometry "issues". It wasn't really designed with pot rotation in mind and has been a "flaw" since day-1.

Why mention the seemingly obvious? well, just as when adjusting the pot in a wah circuit and paying particular attention to the end of sweep of the pot itself when securing the pot's locknut one naturally sets the pot in the bracket so to allow for that extra movement (1/8" to 1/4") for the bypass switch ...right?... sure, of course, but you'll quickly notice (in a vibe) it robs you of some noticable amount top end LFO speed.

This is one reason I personally like the LED/LDR to single pot solution in spite of the light/dark adaptation issues. It lets you map the actual pedal travel onto the LDR resistance in a way that's independent of the actual mechanical travel issues, to any degree you want to take the trouble to make it work. Electronics is easier to scale and limit than mechanics. That's just me. Others may find that their mileage may vary.

[Brymus]

No more progress made,
Had to take the little one to get some stiches last night (he's OK now)
But I am behind on some things ,so I may not get to finish this until tommorow 
Sorry for the wait.

[R.G.]

No more progress made,
Had to take the little one to get some stiches last night (he's OK now)

Oooowww! I still remember the stitches in my big toe from dropping that chunk of broken bottle on it when I was five. No fun. Glad he's OK now.

But I am behind on some things ,so I may not get to finish this until tommorow 
Sorry for the wait.

Don't sweat the wait for me or you. The little one is worth more than a day or two without a pedal.

[Brymus]

Almost
There
As you can see,I ground down the mounting for the pot so I could make the RS dual pot work.
It took a 1/4" washer with a 3PDT plastic washer,but its pretty secure.
The gear is off a "life pot" it had a "D" shaft so I ground a flat spot into my pot and used it.

The 1000uf caps are fairly big,BUT,
I could have replaced the one in the middle with a 2200uf and it would have fit,but I have more of these.
If I build another I will use an AC adapter and use 3200 uf total.

Pretty much out of 1uf caps now for some reason 

I wouldn't recomend putting the depth pot where I did,its really tight.
I thought it had more clearance,no matter its still fits.

I like the way the pre amp is seperated from the power filtering,and bulb driver .
And I like the way its all star grounded on the PCB,to that end I am only grounding one jack since they ground through the shell.
The layout makes alot of sense after putting it together.
Hopefully I can fire this up tommorow.

Just guessing that the Vreg doesnt need a heat sink?
I didnt add the diodes to elevate the ground,I will order a new Vreg if it overloads too much.

[Brymus]

OK it works 
I have never played one before .but,it does sound like the recordings Ive heard.

I noticed it sounds "vintage" with the bulb set kinda dim.

All the speed change is in just a slight turn of the pot/treadel.
About 3/4 of the treadel is too slow then bam its maxed out.

Yeah, it distorts with humbuckers,guess I need that 15V regulator.
Cause turning down the volume on the guitar gets rid of any distortion.

It is slightly above unity volume when engaged,no hiss, perfect IMO


I need to fix the speed control, spread out over the range of the treadel.
How do I increase the max speed?
And should the bulb go all the way off?
Because it just gets dim and bright.
And where should I splice in a speed indicator LED?

I will get some voltage readings tommorow.
Anything else I can do for you guys while I'm messing with it  ?

I used a 1M for R3 and the 2k[]680R trimmer set up,and the 12Vreg are the only changes from the schematic.
I did use all 3 lugs on each of the dual pots,wired as variable resistors like the old neo vibe schematic shows.

[R.G.]

As you can see,I ground down the mounting for the pot so I could make the RS dual pot work.
It took a 1/4" washer with a 3PDT plastic washer,but its pretty secure.
The gear is off a "life pot" it had a "D" shaft so I ground a flat spot into my pot and used it.

Very nice work!

The 1000uf caps are fairly big,I could have replaced the one in the middle with a 2200uf and it would have fit,but I have more of these.
If I build another I will use an AC adapter and use 3200 uf total.

That's way works fine.

Just guessing that the Vreg doesnt need a heat sink?

No, it doesn't. Actually the TO-92 version works well enough. The currents in the preamp/phase line fed by the the regulator are small.

[R.G.]

OK it works 

Hold your calls, folks, we have a winner!

All the speed change is in just a slight turn of the pot/treadel. About 3/4 of the treadel is too slow then bam its maxed out.
...
I need to fix the speed control, spread out over the range of the treadel.

What pot taper did you use?

How do I increase the max speed?

If you're OK with increasing the min speed too, cut the 1uF caps in the LFO by half; that will increase both min and max. Changing Q11/Q12 to an integrated darlington or changing Q11 to a J201 and changing R40 to a higher value will give you a lower minimum speed before the LFO quits because of loading on the capacitor chain, so changing Q11/Q12/R40 and cutting the value of the capacitor chain will give you a higher max speed with the same min speed.

And should the bulb go all the way off?
Because it just gets dim and bright.

Not necessarily. Almost off. It depends on the LDRs as much as anything else. It's very much a "season to taste" issue.

And where should I splice in a speed indicator LED?

I'd try one in series with the bulb, perhaps with a resistor in parallel with it if the LED gets too bright.
At one time there was a jumper in series with the bulb that would have made the perfect place to do that, but I was entirely too clever and managed to route traces to eliminate it. 

I will get some voltage readings tommorow. Anything else I can do for you guys while I'm messing with it  ?

Looks like you did everything except giving us an order of fries each. 

I like the bent-over heat sink tab on the Vreg. I'd have chucked it into a vise and used a razor saw or jeweler's saw to cut that off. Oh, sure, do it the simple, easy, logical way... 

[phector2004]

Looking good! Your choice of pot/switch placement might have been hard to work with, but I'm sure it looks nice on the outside 

Where'd Q14 go though?

[RedHouse]

Nice build Brymus, good job!

All the speed change is in just a slight turn of the pot/treadel.
About 3/4 of the treadel is too slow then bam its maxed out.

Yep, it's not a slam-dunk as is commonly believed.

I actually import my pots, they have a special taper to even out the speed range with the treadle travel.

Yeah, it distorts with humbuckers,guess I need that 15V regulator.
Cause turning down the volume on the guitar gets rid of any distortion.

That's that blatty blocking distortion I was talking about in another post, you can dial that out by changing R1 (and R2) to a higher value, I've had to use like 27k all the way up to 75k in the past to dial-in vibes for customers "favorite" axe's.

And where should I splice in a speed indicator LED?

There's a couple ways you can go, the Bob Sweet mojo-vibe method and the JC Maillet methods are the most popular and easiest to accomplish.

you'd have to cut a PCB trace to do the JC mod. Both work good but the JC one seems to be able to dial-in a brighter pulse. You definately need the trimmer because it's a fine balance to rob just enough current to light the LED, no easily landed on by picking an available value resistor, or combination thereof. If you do the Bob Sweet version you definately want a higher brightness type LED.

Note to RG: there's room on your board there to put a couple pads for a two-terminal pin header, that way the builder could hook it up easier ...and... if they didn't want a speed LED they could just put a jumper on it, or you could place the pads right on the trace and the builder could just cut the trace if needed.

And should the bulb go all the way off?
Because it just gets dim and bright.

To dial-in the traditional vibe throb/lope you don't want the bulb to go all the way off, you want it to go almost off.

Hope this helps, peace-out.

[R.G.]

That's that blatty blocking distortion I was talking about in another post, you can dial that out by changing R1 (and R2) to a higher value, I've had to use like 27k all the way up to 75k in the past to dial-in vibes for customers "favorite" axe's.

The problem with that is it gives up the unity gain at the same time if you divide the input signal down. The underlying issue is that Q3, 5, 7, 9 and 10 are phase splitters. As such, they can only accept at most a signal of 1/4 of the power supply with any grace. Q1 can't quite follow even that much. For whatever reason, the 22K/47K divider on the input cut the signal by 1/3, and it stayed low. Changing the emitter resistors on Q3 lets you make some of this back up for "unity gain". You still have the issue that Q5 et.al. can't carry much more signal.

The real solution is probably to raise the power supply voltage.  

There's a couple ways you can go, the Bob Sweet mojo-vibe method and the JC Maillet methods are the most popular and easiest to accomplish.
Here is how to do the Bob Sweet (mojo vibe) LED mod on your UVICS:
and here's how to do the JC's LED mod:

Brad, please don't use my artwork for your illustrations.

To dial-in the traditional vibe throb/lope you don't want the bulb to go all the way off, you want it to go almost off.

As I said, it is very much a matter of personal taste.

Just for completeness, there are number of updates to UVICS that have already been done, and are waiting for Bry's experiences. He's done a great job as a volunteer for the first issue, and there are several updates arising out of his contributions.

Hope this helps you keep perspective.

[Govmnt_Lacky]

At the risk of stirring the pot... which is TOTALLY NOT what I want to do.....

What is the back-story on the amimosity between RG and RedHouse?  I could be wrong but it is getting mighty snippy on this thread 

In the end, can't we all just get along and help out Brymus (and others interested) with this project?

[RedHouse]

At the risk of stirring the pot... which is TOTALLY NOT what I want to do.....

What is the back-story on the amimosity between RG and RedHouse?   I could be wrong but it is getting mighty snippy on this thread  

In the end, can't we all just get along and help out Brymus (and others interested) with this project?

There is none, we're past all that.

Where am I sounding snippy now Guv? I thought I tightened up on the communication faux-pas after Beo's post. Help me out here.

Brad, please don't use my artwork for your illustrations.

It's a screen shot of my computer not your PDF artwork, but in the spirit of forum community, sorry. Would you have me delete it from the thread then?

Anyway, I was just trying to help Brymus hook up his LED into your project.

The problem with that is it gives up the unity gain at the same time if you divide the input signal down.

In my experience I don't find that to be the case. When one changes the 47k to 1M (your R3) as Brymus did you increased it by a factor of roughly 21 so when bumping up the input resistor up to even 75k only raises it by a factor of 3'ish so the voltage divider effect doesn't really give up any noticable benefits (unity gain correction) but does control the current into the base of Q1 better. Of course YMMV but that's what I found when I did all that R1/R2 testing for the Forum-Vibe.

Don't get me wrong, I'm certainly not saying your approach isn't golden.

[R.G.]

What is the back-story on the amimosity between RG and RedHouse?  I could be wrong but it is getting mighty snippy on this thread 

The back story as far as I know it is that Brad went nonlinear when I first posted a layout for the univibe circuit in a crybaby shell. It appears to me that he will do or say anything to prevent me from presenting it. You can research the postings in this forum on that issue.

In the first salvo, about April a year ago, he finally said by PM that he was in negotiations with a manufacturer to make his version, I thought, OK, let the guy support himself, and voluntarily held the layout off the web - for over a year. When I finally decided he was either rich from it or not gonna be, I posted this run, carefully renaming it, as he was screaming about trademarks in naming last time, over a year ago. After his first post on this thread, I asked him politely by PM to not run the argument again. He ignored that. From my standpoint, he grabbed any possible nay-saying to be had.

I have formed the theory that the real issue is he views the concept of a univibe circuit in a crybaby shell as his personal property in some way, or maybe just not mine in some way. It is the only thing I can come up with for why he'd continue; and a little odd when I'm not making a penny out of this, only enabling the DIYers Brad says are not his market. He's PO'd about something, anyway. I've asked him both privately and in public to butt out. No good results from that yet.

You'll notice that I respond to his comments, which come in the form of nitpicking with things he'd like to present as problems or failures in UVICS, and that he has adopted a specious well-*I'm*-being-nice-now pretense as well. It's fairly classical passive-aggressive technique. I recognize the playbook, as I've had to deal with a few people with this syndrome in the past. Unfortunately. What does not work with these people is to not comment on their little ploys.

In the end, can't we all just get along and help out Brymus (and others interested) with this project?

Sure. That's what I'm trying to do. But I'm past politely talking to Brad off-line or silently ignoring him. 

[R.G.]

It's a screen shot of my computer not your PDF artwork, but in the spirit of forum community, sorry. Would you have me delete it from the thread then?

The fact that it's a screen shot and not the original format does not make it any less a derivative work nor change its standing under copyright law.

Yes, please delete it.

[RedHouse]

I removed the pic from the thread for you.

Lets put aside the funk and weidness and move forward ok?.

[GP]

You'll notice that I respond to his comments, which come in the form of nitpicking with things he'd like to present as problems or failures in UVICS, and that he has adopted a specious well-*I'm*-being-nice-now pretense as well. It's fairly classical passive-aggressive technique. I recognize the playbook, as I've had to deal with a few people with this syndrome in the past. Unfortunately. What does not work with these people is to not comment on their little ploys.

I think it's plain as day to anyone reading this thread what Redhouse/Brad is up to. That said, I'm not convinced that you sniping back is really helping things along. It seems to me that Redhouse is rather enjoying trying to wind you up and, well, he's sort of succeeding isn't he? Isn't your rising to this provocation somewhat diluting the fact that you're doing a really wonderful and selfless thing by providing the community with so much of your time and work?

I'm pretty sure - no one's calling you a duck (sic)

[RedHouse]

{Ooops, I was trying to edit a post and made a new one}

I think it's plain as day to anyone reading this thread what Redhouse/Brad is up to.

Just try'in to help GP. I agree it's a great contribution to the forum by RG, much kudo's.

[R.G.]

I removed the pic from the thread for you RG, happy now?

Thank you.

Lets put aside the funk and weidness and move forward ok?.

I'm good with that.

I think it's plain as day to anyone reading this thread what Redhouse/Brad is up to. That said, I'm not convinced that you sniping back is really helping things along. It seems to me that Redhouse is rather enjoying trying to wind you up and, well, he's sort of succeeding isn't he? Isn't your rising to this provocation somewhat diluting the fact that you're doing a really wonderful and selfless thing by providing the community with so much of your time and work?

Could be. Doesn't feel like a true troll, though. I think his agenda is pretty much spite, not trolling. It's subtlely different. In any case, the most effective response to PA attackers is to call them on it. Brad's said he's misunderstood and that he's trying to be good, please don't be weird at me any more, R.G.

OK. Can do.