Original Univibe Enclosure Dimensions/Drawing

[HD Evans]

It's easy to find pictures of the originals, but I have yet to find the dimensions or a technical drawing of the enclosure of an original Univibe.  Special thanks to RG Keen, GGG, and many of you for your informative posts.  I just finished the smoke test on my Neovibe (fired up and worked on the first try!), and now I want something different to put it into.  Even if I can get something hand drawn, I will clean it up in CAD and make good drawings available to all.

I have a good friend who operates a foundry,and I will be using the plans to make a sand cast aluminum enclosure body.

Thanks!  If this information exists anywhere, I bet this is it

[R.G.]

The info can be found.

But the original was folded sheet metal, not cast.

For quite a different set of technologies, completely outside effects pedals, I need sand cast aluminum and iron from time to time. It's quite difficult to find a working foundry that will take small jobs. Would you mind putting me in touch with your friend?

[mth5044]

I have the original unit some 3000 miles away haha. I'll be returning home the 1st of september, so if you don't get your dimensions by then, I'll get them for you.

[HD Evans]

RG: he can be finicky because he does it as a hobby. I'll ask him if he's interested in doing some short run stuff and put you in touch if so.

mth5044: that would be fantastic! I'm having a devil of a time finding any drawings myself.

[R.G.]

RG: he can be finicky because he does it as a hobby. I'll ask him if he's interested in doing some short run stuff and put you in touch if so.

That's OK, never mind. I keep hoping to find a short-run commercial place. I hate to intrude on someone else's hobby stuff. I sometimes need either an aluminum or iron casting for things, and have had to make do with machined or welded-up fabrications, when casting is the obvious way to do.

[HD Evans]

Ever considered just building your own forge?  You can get into aluminum with some refractory, a couple of flower pots, a heating gun, and a crucible.  It's surprisingly simple, although moving up to iron/steel is more of an undertaking.

I'm still a bit surprised no one has chimed in with some measurements from an original unit...  A nice heavy forged base for the control panel would be really cool.  But sheet metal is easier, and I doubt I'm the only one who might want such a beast.  Then again, this *is* a diy site.

For testing, I've been running my neovibe off an old laptop power adapter that outputs 20V and works beautifully.  I have a power transformer rated at 25V AC 500mA.  When loaded and running through the regulator, I would expect it to still be just barely within the operating specs for the regulator.  I'm tempted to hook it up and check voltages to make sure I'm in the clear and otherwise I'm tempted to just toss in a couple of loading resistors.  Thoughts?  Thanks!

[R.G.]

Ever considered just building your own forge?  You can get into aluminum with some refractory, a couple of flower pots, a heating gun, and a crucible.  It's surprisingly simple, although moving up to iron/steel is more of an undertaking.

Actually, I have. I do some amateur machining and mechanical tinkering as well as electronics. I've read fairly extensively on smelting, casting and forging, to the point of looking at building a cupola or something as simple as a pottery kiln for aluminum. My conclusion is that the mechanical setup and safety issues to be handled mean that it would be very expensive in terms of time to get a useful setup done properly and safely. For me, I'm quite willing to pay someone who's already made that investment so I don't have to go do the infrastructure setup. It is more the time involved that stops me.

I'm still a bit surprised no one has chimed in with some measurements from an original unit...  A nice heavy forged base for the control panel would be really cool.  But sheet metal is easier, and I doubt I'm the only one who might want such a beast.  Then again, this *is* a diy site.

I have repaired a number of these things over the years, but not for a while. It didn't occur to me to measure one out and document it. I did do this for the AC30 cabinet, in a weak moment, though. 

For testing, I've been running my neovibe off an old laptop power adapter that outputs 20V and works beautifully.  I have a power transformer rated at 25V AC 500mA.  When loaded and running through the regulator, I would expect it to still be just barely within the operating specs for the regulator.  I'm tempted to hook it up and check voltages to make sure I'm in the clear and otherwise I'm tempted to just toss in a couple of loading resistors.

Sounds like a very reasonable test. It may need a heat sink on the regulator. All the voltage above the 2V-3V dropout voltage at the regulator input goes directly to waste heat.

[HD Evans]

I still haven't found the dimensions elsewhere, so MTH please measure away when you get a chance.  I truly appreciate it, and will use the information to make sure that anyone else who likes playing with metal can make an authentic enclosure as well!

As a recent development from working on my Neovibe, Rat Shack has a 12.6VAC 1.2A transformer that works beautifully.  Running at maximum load, the regulator never sagged from 15.0V.

RG- A couple of things out of curiousity: 
1.) the UVICS baby board looks like it should work fine with a Neovibe to use a single pot speed control, any special considerations to make this work?  At first glance it looks like a perfect drop in.
2.) You've mentioned several interesting layouts that you've put together over the years.  Would it be possible to have copies of what you have?  I'm enjoying the Univibe circuit quite a bit recently, probably because it's enough of an odd-ball.  I'm even considering splitting the circuit up into a more modular form to facilitate tinkering.  None of this will be used for any type of commercial use, and anything I learn will be shared with the community.  Send me a PM if you're up for letting me see what you have.  Thanks!!!

[R.G.]

1.) the UVICS baby board looks like it should work fine with a Neovibe to use a single pot speed control, any special considerations to make this work?  At first glance it looks like a perfect drop in.

I came up with that long ago for an 8-stage version I was playing with. It works fine with the normal circuit, especially considering that UVICS *is* the same circuit, just squashed into a different form factor.

There are a couple of special considerations. One is that the "gain" of every LED/LDR in terms of LDR resistance per ma of current into the LED varies. For each setup you may need to change the emitter resistor of the transistor to change the scaling constant of volts at the base to current in the LED.  Another is that a real solid-granite design would take into account the "end" effects of the pot. It won't go fully to zero nor fully to +15, and if it did, the transistor would still subtract off a little at the very top and very bottom of the rotation. This is somewhat compensated for by the fact that mechanically a wah shell won't turn the wah pot from rack to rack anyway.  Lastly, LDRs all have some light adaptation and dark adaptation. After being lighted, they go to a slightly lower resistance after a while. After being put in the dark (darkened??) they drift to a slightly lower resistance after a while. So the LDR drifts a bit after being set. It's not rock steady, a consequence of the LDR's nature. Not bad, but there.

2.) You've mentioned several interesting layouts that you've put together over the years.  Would it be possible to have copies of what you have?  I'm enjoying the Univibe circuit quite a bit recently, probably because it's enough of an odd-ball.  I'm even considering splitting the circuit up into a more modular form to facilitate tinkering.  None of this will be used for any type of commercial use, and anything I learn will be shared with the community.  Send me a PM if you're up for letting me see what you have. 

Depends. A lot of them were incremental improvements on the basic clone/Neovibe. I did one eight stage, a few for special purposes. I did do a "phase line" version. If you want to do a modular version, let me know what you're thinking, and I'll see what I can find. I do PCBs faster than I do crosswords, so it's easier to go make a fresh one if there is a goal in mind.

[HD Evans]

In terms of modularity, I've thought it could be interesting to separate out major blocks...  At least using separate boards for the LFO/lamp driver, and another for the Preamp/Phase/Mixing.  Even separating out the preamp could be interesting.  The reasoning behind this is to make experimentation easier.  Since the LFO/lamp driver is truly a separate circuit, it would be much easier to build one that can be used by running a couple of wires wires to another board containing a lamp (or perhaps piggy-backing boards and popping the lamp into a light shield from beneath.)  I'm curious to see how mods such as the gain/offset lamp driver end up working out.  I'm not overly interested in messing with the Phasing circuit, since most of the tonal character seems to rely on it.  My suspicion is that the preamp could be improved vastly and might go as far as to involve a couple of tubes to that end for fun.  This is hardly a set of specs to work with, but perhaps its' sufficient to start dialogue if you're interested by where I'm going with this train of thought.

[mth5044]

So, I flew across the country earlier this week.. and I measured the enclosure.

But.

I think I might have been on crack when I did it, because I was just translating the measurements to illustrator, and something isn't adding up. I'll see if I can figure out what I was doing. I blame jet lag.

And crack I guess.

[HD Evans]

I appreciate the effort, hopefully you'll figure it out soon...  You know, once the jet lag/crack wears off and you realize you were measuring the thing in cubits