So I'm building the Neovibe finally, had a lot of trouble finding a suitable lamp . Now I used a 12 volt 30 mA minilamp and 4 ldr which can be moved back and forward. Hope it's going to work.
(http://i113.photobucket.com/albums/n233/alfafalfa/IMG_0001.jpg)
So now it's time to cut the film capsule box and cover the whole arrrangement with the removable lid.
Has anyone so far encountered any hum from the ac coming right into the board ?
Alf
I tried an ac transformer on my neovibe and it humed real bad so I went with something else. If you move your LDR closer to the light it will work better. I used some black tape to cover my LDRS I wound the black tape back wards around my first 2 fingers to make a O and put some tape on the top to cover. I have pics but I dont know how to post them ???
I guess we all need some help ah :>) ...
walrus
Thanks Walrus for the black tape advice but I'm going to proceed as R.G. wrote in his description.
You take a black film canister saw of half and cover the lamp and Ldrs with it . So the whole assembly will be in the dark.
Pictures you can post by putting them on a site : I use Photobucket, then you paste the url on this site ( first click the picture icon ) in your message.
Alf
Well I finished my Neovibe and am biasing the lamp. I had the wrong trimpot in, so I put a 200 ohm resistor in. The lamp won't come on only when I shortcircuit the resistor, so 200 ohms is too much .
When it's zero the lamp comes on but it won't shine brightly.
My question is how bright does the lamp have to get ?
It's a 12 volt 30 mA lamp ( see picture) . It will also be rather dim when I connect it e.g to a 9 volt battery.
So do I have the wrong lamp ?
The lfo works well and so does the speedknob.
I built the NeoVibe a while back and run ito a similar problem (me thinks) and as always RG to the rescue...........he suggested replacing the 200R trim with a 500R......I had a 1K in hand so I did and it worked fine.
Here's the thread......
http://www.diystompboxes.com/smfforum/index.php?topic=49667.msg370448;topicseen#msg370448
Aharon
Maybe try a super bright LED....you will get more light with less power and voltage and without any heat.....
That could work too !
I never had any problems etching the board. But then I have now finally standardized my etching procedure after a lot trial and error
(http://i113.photobucket.com/albums/n233/alfafalfa/NeoVibeboardfalons3.jpg)
Anybody else tried a led , does it have the correct risetime?
Alf
I would not think so............
Try a bigger trim.............
Aharon
An LED will not work for the Neovibe. The viewing angle is much to steep to feed light to 4 LDRs.
Also the speed that an LED turnes on and off will through off the Neovibes characteristic feel.
Not to mention that the bulb uses 12v and an LED uses 2v or less as well as the current difference.
Do a search for SteveB and Neovibe and you will find pics of a monster sounding Neovibe he built.
John
Thanks John , I found the thread and it has a lot of good info.
But one thing I haven't been able to trace so far: how bright is the lamp supposed to get ?
I noticed , Steve B also used a small "grain of wheat " type like I used myself.
I sent him a personal message and hope he will respond .
He gets an awesome sound !
Alf
I used a radio shack 12v/25ma bulb. I think SteveB did as well. His photo may have been of another one though as it's an old photo.
Steve is a nice guy, he helped me with mine...
The distance and spacing of the LDRs can make a differece in the sound of the neovibe. I went with something like steveB's but I spaced the LDRs so they all "see" the bulb at thye same angle and see the broad part of the filament as opposed to the side if the filament which looks like a dot (hard to describe that...)
The bulb should be dim and orange with the depth set at 0 and the bulb should be bright and white at max depth but not you can set the trimmer to find a nice max setting. Sometimes if the bulb is too bright you can get a thump sound...
The Problem with the Neovibe is that there are a few different ways you can make it. They all sound different and you can use several different specification parts to get to a "good" sound. The LDRs are a big part of how mine came to life. I got a set from a friend that really made a big difference in how it sounded. Fast and wide ranging LDRs seem to sound best in my opinion. But which ones to buy? I don't know...that's part of the problem and confusion, there isn't a specific part that you can go out and buy that is listed anywhere.
All the info is in the threads here on the forum, you need to dig a little though.
John
John ,
I got a reply from Steve b and he said he lamp was a Radio Shack type and was as bright as a torch with weak batteries.
So I'm going to try my setup the way it is and will soon find out if it's getting bright enough.
I think I understand what you mean with the quote below .
Quotebut I spaced the LDRs so they all "see" the bulb at the same angle and see the broad part of the filament as opposed to the side if the filament which looks like a dot
All the ldr's are on long wires so I can bend them quite a lot.
Alf
I'm sorry I forgot to mention that the black tape was temporary so I could do my final tuning :icon_redface:
Interesting pic from Fulltone's website. This is said to be a picture of the LDR's and Bulb under the light shield on a real vintage univibe, which BTW is covered by a shiny reflective tin cover (not quite a black film canister):
(http://www.fulltone.com/images/OldUnivibe-cells.jpg)
If true, this kinda suggests to me that the real vibe functioned a bit more from the bounced ambient light within the shield and perhaps less from the direct light from the bulb although the pic shows that the bulb is oriented so in such a way that some direct light can reach the faces of the LDR's from an angle.
I'll have to try it myself, I've mostly used the typical arrangement we all use, LDR's facing Bulb (sometimes at slightly off-angle).
De-fogging time again.
The photo from the fulltone site is of the LDR arrangement on a real Univibe. They did use a shiny-inside bent-tin enclosure, and it was indeed to get a much more diffused light on the LDRs.
I came up with the film cannister to get an easy light tight enclosure. In my first instructions I suggested lining the inside of the cannister with aluminum foil. However, pointing the LDRs at the lamp works. I also later came up with the tin-can light enclosure, which uses scissors-cut tin can to make the enclosure and glued-on aluminum foil for the light mixing chamber. If you're going with the tin-can style, mount the LDRs flat as in the original. The PCB has holes drilled in two places to allow both horizontal and vertical mounting.
Confusion about the vibe creeps in two ways: either by "experts" hyping their wares or by newbies opining about why things happened. Opining and hyping get accepted by even newer newbies and extended. This causes what might be called "information drift".
Wide range and fast is correct for the LDRs. These are competing requirements in LDRs, so every LDR is compromise. LDRs are so rare that my advice has always been - put in what you can get now, and search for the perfect ones while you enjoy your pedal.
Real univibes had a wide range of variations too. The key to a good sound is wide range, fast LDRs and tweaking the mix of dry and wet sound at the output mixer.
As well as doing the rest of the build correctly, of course.
All for now. Gotta go build fences.
This is very interesting guys, so I tried a little modding myself.
I just cut off a piece of aluminium foil and put it loosely inside the film canister and ..... got a helluva noise ..because the foil shortcircuited some of the ldr's .
So I took out the kining on the inside and bent the ldr's so they are facing upwards halfway and put some foil in the canister cap.
So now it's working again and I must say I do like the difference in sound ; it seems a more pronounced effect.
I'm going to experiment a bit more . This thing can benefit a great deal from experimentation.
Alf
Same results here. I'm now experimenting with shrouding the bulb and letting the LDR's actually work off of the reflected light from the roof of the light shield.
I also am having a theory that part of it might be the bulb's contribution, when the LDR is not directly lit, the bulb is able to be run a liitle hotter, seems like more within it's changable brightness range.
I think (I'll know more later when I can profile it) that bulb's are faster at changing brightness when it goes from a definate on-state, the dull orange glow-to-bright as compared to when it goes from nearly off to some state of on'ness.
BTW, I wasn't knocking the Black Film canister idea RG, I was just pointing out the original had a different setup.
Quote from: R.G. on October 04, 2007, 09:38:21 AM
De-fogging time again....Confusion about the vibe.....
I re-read your post a couple times now and I can't figure out what the
fog and
confusion is you're speaking of RG, wha'sup?
Quote from: RedHouseI re-read your post a couple times now and I can't figure out what the fog and confusion is you're speaking of RG, wha'sup?
Well,
QuoteMaybe try a super bright LED
QuoteThat could work too !Anybody else tried a led , does it have the correct risetime?
QuoteI would not think so............ Try a bigger trim.............
Quotehow bright is the lamp supposed to get ?
QuoteFast and wide ranging LDRs seem to sound best in my opinion. But which ones to buy? I don't know...that's part of the problem and confusion, there isn't a specific part that you can go out and buy that is listed anywhere.
QuoteThis is said to be a picture of the LDR's and Bulb under the light shield on a real vintage univibe ... If true, this kinda suggests to me that the real vibe functioned a bit more from the bounced ambient light within the shield and perhaps less from the direct light from the bulb
R.G
As usual...you are teaching the man HOW to fish.
Redhouse,
What sort of leds did you use , I mean their range ?
Alf
No reply to my own post .. but I just found I had made a mistake with the speedpot.
Mine has 4 pins x2 that is and one of the outer pins I used by mistake , it's going to the pot's housing.
So I corrected this and now it's working better.
While doing this I took off the canister's top to see if the light was working properly and now I am sure that the amount of reflection from the foil in the cap reflected back to the ldr's has a lot to do with the sound.
It changed definitely when I put the cap back on.
And how much of the light is reflected and its diffusion must also be taken into account.
The ldr's are now pointing upwards and don't get any direct light from the lamp which is below the ldr's now. Just the reflection.
these are my findings so far.
Alf
Quote from: alfafalfa on October 05, 2007, 04:34:53 AM
Redhouse,
What sort of leds did you use , I mean their range ?
Alf
LED's?
Quote from: Tony Forestiere on October 04, 2007, 10:16:18 PM
R.G
As usual...you are teaching the man HOW to fish.
Cracks me up sometimes, as folks want to move on, try other things, alternative builds, thank heaven someone's willing to save us lost lambs just wandering around aimlessly in the fog all confused about what we are doin, wow it's good to be alive! :icon_confused:
Now then, where's that bait-can and soldering iron, I've got stuff to build ...and test ...for myself. :icon_rolleyes:
QuoteRedhouse,
What sort of leds did you use , I mean their range ?
Alf
LED's?
Sorry redhouse, I meant
LDR's of course !! :icon_redface:
What is the value in light and in darkness ?
By the way , I had another look at the original ldr's in the Univibe and realised that these only pick up light from above while mine also pick up some amount from behind .
I am right that they are somewhat light sensitive from the back too ??
So I may have to try and lightproof them from the back. (http://i113.photobucket.com/albums/n233/alfafalfa/ldrsrechtop1small.jpg)
Alf
Quote from: alfafalfa on October 07, 2007, 05:41:10 AM
Sorry redhouse, I meant LDR's of course !! :icon_redface:
What is the value in light and in darkness ?
By the way , I had another look at the original ldr's in the Univibe and realised that these only pick up light from above while mine also pick up some amount from behind .
I am right that they are somewhat light sensitive from the back too ??
So I may have to try and lightproof them from the back.
Alf
I have used all these:
These work very well:54C679 50k~200k/Lt 20M/Dk (Mouser)
NOTE: Small Bear has them now and I believe this is the LDR that RG recommends for his Neovibe.
(check his PDF to be sure)
These are a little cheaper and also work work very well:G15177 1k-4M (Electronic's Goldmine)
G15176 1k-20M (Electronic's Goldmine)
G15396 - cut in half (Electronic's Goldmine)
using only the LDR side, these worked surprisingly well but all were not the same,
I had to cut open like 6 or 7 of them to find 4 with the same LDR.
I like these better but they are more spendy:NSL-5540 30k/Lt 20M/Dk (Allied)
and these will also do the trick:
NSL-5152 15k/Lt 5M/Dk (Allied)
NSL-4140 14k/Lt 8M/Dk (Allied)
If light bleeding through from the back is a concern (other than your lamp being behind your LDR) the LDR's in the hermetically sealed Metal-Can package with the little glass windows are the ones to use.
The old brown circuit boards in the original univibes look (from pic's) as though they were better at blocking stray light from entering the rear of the light box, maybe better than the green epoxy (FR4) boards we use these days?.
Which reminds me of a story, I've had to address this in the past by spray-painting a small circle of flat black on the board (
before loading any components) where the light shield is going to be, this keeps out external light when I have to have the boxes open for adjustment etc, you can see in this pic.
(I don't use RG's black film can method)
I use a different light sheild, one of my own idea's, it is a little more hastle to build (but at least it's mine). It's made from a 3/4" copper pipe end-cap bought at the local DIY store for like 99¢, it has to be cut down a little because one of my design goals was the light box can't be very much taller than the tallest component on the board which currently are those stacked film caps. My boards all have a triangle of 3 solder pads and the light shield is soldered down to the board as can be seen in the pic's below.
As the story goes, my Vibe-Baby board turned out to have an issue with stray light. It never occurred to me when I built the first unit until the user came back after a gig and reported "
it sounded different" at his gig, I puzzled over this for a while and looking over the unit from time to time I couldn't really tell why....until one day as I was looking across the room at my VOX 847 sitting over there on the floor, it dawned on me ...the wah shell has a big 'ol hole in the top under the pedal where the pot is mounted which when the pedal is back, is quite open to the elements. The guy's band uses stage lighting ...hmmm.
Could it be? well to be true to my MO (which is:
let's just test that theory!) I plugged the Vibe-Baby into a guitar and amp, grabed a 4-cell maglite and shined it on the pedal from across the room and yep ....it 'vibed!.... well it was back to the think-tank for me (
that's what I call it when I'm sitting at my bench doing nothing ...the think-tank) and that's when I came up with my current system as shown below which works well and keeps to the goal of not modifying the wah shell:
A
vintage layout Vibe-Baby (Electro's and Mylar caps, no bulb-offset or mixer trim pots)
(http://users.isp.com/brad_anne/guitar/DSC00550_DSC00551_small.jpg)
here's a pic of my lightbox system in my testbed-box, this is my go-to box for 'vibe experimenting:
(built into a Data switchbox I got for 50¢ at the charity shop)
(http://users.isp.com/brad_anne/guitar/dsc00556_small.jpg)
Note the chart taped to the lid which shows the capacitor
values on each of the four 5-position switches, way easier
than soldering and re-soldering new cap's for testing.
In looking at your latest pic, with your LDR's standing-tall with bulb-in-socket for testing purposes, it seems to me you could just slip a piece of black shrink-tubing over the bulb leaving the top open that should shroud the bulb enough to keep from directly lighting the LDR's (set them equal height to the bulb)
BTW; the pic above was my 1st Vibe-Baby, after two of those (one for JC) and a few other non-WahShell boards, I have switched from flat-black inside the cover (light shield) to flat-white (or just polishing it and spraying matte-clear).
After this recent 'round of experimenting I'm leaning toward changing to mounting the LDR's facing straight-up (like the original) and partially covering the bulb sides so it has to shine upward using more
bounced light and less (if any) direct light.
-Brad
I got some of these from AllElectronics.com for my impending Vibe build.
(http://www.allelectronics.com/images/gold/large/MIR-22.jpg)
They're highly polished stainless steel mirrors. I should be able to get 2 light boxes out of each one (obviously more than I'll need). They're kind of thick so it'll be a challenge to bend them, but I'd think they'll give about the best reflective light inside the box of anything you could make or buy. They're extremely well polished and look just like the one in the stock picture above. Best part is they're 5 for $1.
I'm just wondering if something this highly polished is really the best for the Vibe application. Maybe adding some fine sanding to disperse the reflected light would be better? I also have access to glass bead blasting. It'd still be reflective to light, just not in an image kind of way. I have several of the mirrors, maybe I'll make a couple differently and swap them out to see what works better. I'll post results here of course.
Cheers,
- JJ
You're working too hard at it.
Light mixing chambers are an old technology for making light distribution uniform across an area. They work best if the entire interior is highly reflective and also non-planar. A crinkled shiny surface spreads the light around and evens it out. Just gluing the shiny side of kitchen aluminum foil in there works fine.
Thanks Redhouse for the very extensive explanation.
You gave me some very useful clues.
The black canister is also "open " at the bottom where I glued it onto the board so I'm going to paint this part black and try a little wrinkled foil as an inside lining. The cap has already had that treatment.
( must redo it I notice ! )
(http://i113.photobucket.com/albums/n233/alfafalfa/reflectiefoliesmall.jpg)
Any suggestions for good univibe examples to use for the reference sound besides the common ones:
Pink Floyd, Jimmy , Robin Trower ??
Alf
Quote from: alfafalfa on October 08, 2007, 09:41:00 AM
Any suggestions for good univibe examples to use for the reference sound besides the common ones:
Pink Floyd, Jimmy , Robin Trower ??
Alf
Nope, you're on your own there friend, the univibe means different things to different folks, like 'ol David Gilmore makes his sound way different than Robin Trower, there are lots of different styles and applications for the 'vibe.
As for me, I like Robin Trower's sound in
Bridge Of Sighs, the outro to
Too Rolling Stoned, the studio version of
Daydream, all of which use different speed and intensity settings. My favourite Gilmore might be
Time. My favorite Hendrix is definately
Machine Gun from Band Of Gypsis.
The Trower sound relies heavily on adding reverb, the 'vibe by itself doesn't Trower well without some kind of delay.
(after the vibe, and normally after OD)
Speaking of
Machine Gun, some time back on the trading forums I managed to do a B&P's and score a copy of the whole new years eve show(s) both early and late, interestingly in the early show Hendrix has his univibe set totally different, it sounds like it's on the vibrato setting at full intensity (has that wild out-of-tune wang sound).
Quote from: R.G. on October 08, 2007, 12:59:41 AM
You're working too hard at it.
Light mixing chambers are an old technology for making light distribution uniform across an area. They work best if the entire interior is highly reflective and also non-planar. A crinkled shiny surface spreads the light around and evens it out. Just gluing the shiny side of kitchen aluminum foil in there works fine.
C'mon now RG, don't be a buzz-kill, let us experiment with our stuff.
Fiddling around with film can's could be considered
working too hard too buddy. :icon_biggrin:
Sorry for reviving this...
Has anyone tried spraying/painting the interior of the light box flat white? According to the additive process of color theory, a white surface reflects all colors of the visible spectrum equally (400nm-700nm, or visible RGB). Using a flat paint texture would even out the lamps reflectance by eliminating glare in areas of the chamber.
just my $.02
The lamp need not be 12 volt. 1.5 volt lamps have been tested and are known to work in the Neo with correct biasing. I offer both a leaded and a socketed version:
http://www.smallbearelec.com/Detail.bok?no=645
http://www.smallbearelec.com/Detail.bok?no=646
I mention this particularly for overseas builders who don't have access to those Radio Shack parts.
Regards
SD
Quote from: Tony Forestiere on October 25, 2007, 07:54:07 PM
Sorry for reviving this...
Has anyone tried spraying/painting the interior of the light box flat white? According to the additive process of color theory, a white surface reflects all colors of the visible spectrum equally (400nm-700nm, or visible RGB). Using a flat paint texture would even out the lamps reflectance by eliminating glare in areas of the chamber.
just my $.02
Yes I have.
I have been experimenting for the past couple months with flat black, flat white, polished copper and bright tin. The most difference seems to be between the flat black and the flat white. All work and all work well but IMHO have a different sound.
I'll try to use words to describe sound:
Regarding glare, I'm feeling certain that direct light (from filament to LDR) seems to be what creates the "warble" to the shifting sound, glare like from a shiny surface causes another point-source of light and depending on the LDR's the sound can be better, or worse. This maximum warble is like the Hendrix sound on Little Wing or Trower's Bridge Of Sighs (although that sound needs much reverb)
With no direct light and no glare at all (just ambient reflection) and with the LDR's angled to avoid the direct light from the bulb element causes the smoothest phase shifting, is
not the sound you want for Bridge Of Sighs, it's more like a swishy Gilmour sound like on "Time".
Makes me wonder if the original light cover was polished shiney or was just tin plated and sometimes not shiney, that could account for much of the sound differences.
Hope that makes some sence.
Interesting stuff Redhouse...
I think you're definately right as although my build isn't complete and i have many bugs to work out, right now i have the ldr's flat on the bottom and they get pretty much no direct light. The surface of the light box is covered with aluminum foil. Through all the noise and other problems i'm having i can detect the phasing sound and it's definately more shimmering then deep as far as i can tell. Of course, there may be other reasons for this in my case, as i'm having other problems...but it may go a little way to confirming what you have said.
I have come to the conclusion that after having experimented with the neovibe for a couple of months now the way the light hits the ldr's is maybe the most important factor for its sound.
Redhouse you findings are very interesting and have been a great help to me.
What would be interesting is if some you guys could put up a soundclip of your vibes.
I will do this for mine, "Esnips" is what I use for this.
Then we have some reference.
I am going to listen to Hendix's Little Wing closely now.
Alf
Well here is an example of my Neovibe.
(Don't mind the playing too much)
Ibanez guitar 270 , singlecoil , 2 tube amps miked and a little reverb.
What I noticed is that if the speed is slower the light intensity goes down too and the effect is less noticeable.
I f the speed goes up a bit it gets brighter and the effect is better and if it's too fast the lamp has no time to become dark so much less effect.
Did you notice this as well ?
http://www.esnips.com/doc/47cb4e48-7068-43ee-878b-190e4616b04c/neovibe-ex-2-mp3 (http://www.esnips.com/doc/47cb4e48-7068-43ee-878b-190e4616b04c/neovibe-ex-2-mp3)
Now completely dry:
http://www.esnips.com/doc/3fa35f71-b4ce-469a-b472-343cb5238641/neovibe-ex1 (http://www.esnips.com/doc/3fa35f71-b4ce-469a-b472-343cb5238641/neovibe-ex1)
Alf
Alfalfa:
How do u have your ldrs set up? Are they flat on the bottom or are they facing the lamp and what kind of a light box are u using? If i had to guess from the sound i would say you have the ldrs facing the lamp at least slightly (not on the bottom facing up?)? Just wondering if my guess is correct...
Hi rhdwave,
Yes they are facing the lamp like in reply # 24 above. They are not in the least down on the bottom.
What should I do ? Have you got any suggestions ? They would be most welcome !
Alf
Quote from: alfafalfa on November 18, 2007, 01:17:03 PM
Hi rhdwave,
Yes they are facing the lamp like in reply # 24 above. They are not in the least down on the bottom.
What should I do ? Have you got any suggestions ? They would be most welcome !
Alf
Alfalfa, i thought your clips sounded pretty good. But if you want to change the sound and you have something in your head, i would see if Redhouse has any ideas. He's been researching this for a while and has compiled different sounds for different positions of the ldrs. I'm curious to hear everything he has to say about it as well. Real good stuff.