Easyvibe vs Neovibe
A friend sent me an easyvibe perfed up and I started looking into the workings of it.
I added a 20K trim pot to replace the 10k/10k mixing resistors at the output of the circuit.
The effect seemed a little too subtle and this allowed me to dial in the balance of the phase circuit.
I still think the easyvibe is a bit weak in the depth of tone and effect. More on this below.
Member Tungngruv made the Easyvibe perfboarded here
(http://www.mrdwab.com/john/EZVibeperf1.jpg)
(http://www.mrdwab.com/john/EZVibeperf2.jpg)
(http://www.mrdwab.com/john/Tweedvibe.jpg)
I rehoused the esyvibe in and oak box with tweed covering
SteveB posted some clips here a while back of his Neovibe build that blew me away.
These clips were recorded with a laptop mic and although less than ideal acoustics,
they were the real univibe sound not unlike Hendrix live (Band of Gypsies)
Here is Steve's build.
(http://www.mrdwab.com/john/vibe-outside.jpg)
(http://www.mrdwab.com/john/vibe-inside1.jpg)
(http://www.mrdwab.com/john/vibe-inside2.jpg)
(http://www.mrdwab.com/john/vibeinside3.jpg)
I got to talking to Steve about his build and I wanted to send him the Easyvibe for comparison.
He made a few clips of the Easyvibe and a few of the Neovibe
Here are the clips:
www.mrdwab.com/john/ez-vibe1.mp3
www.mrdwab.com/john/ez-vibe2.mp3
www.mrdwab.com/john/ez-vibe3.mp3
www.mrdwab.com/john/ez-vibe4.mp3
www.mrdwab.com/john/neo-vibe1.mp3
www.mrdwab.com/john/neo-vibe2.mp3
www.mrdwab.com/john/neo-vibe3.mp3
www.mrdwab.com/john/neo-vibe4.mp3
This last clip alternates between the two vibes.
This one is using my Screamer pedal (TS-808 with mods) ,
I kick on the Neo-Vibe, then turn it off at the beginning of the next phrase.
Then, I turn on the EZ-Vibe, turn it off & end with the Neo-Vibe.
www.mrdwab.com/john/neovibe_ezvibe.mp3
The clips were recorded like this:
71 Strat with a HB in the bridge position. The amp is a '70 Princeton Reverb with a 12" speaker.
The clean sounds were using nothing but the vibe into the amp.
The volume is on 3, treble on 5 or 6, bass on 4, reverb on 3.
I think I kept the intensity all the way up on most samples.
The Trower stuff is using a Marshall Shredmaster pedal after the vibes with the same amp setting.
For the Neo-Vibe the intesity is around 2 o'clock most of the time.
On the slower speeds, I may have gone higher with the intensity.
Sound differences between the two:
My ears tell me that The Neovibe has a bit more sweep into the lower mids giving it a deeper effect.
More vocal into that "we-yow" sound as opposed to the Easyvibe which sound more like "we-you"
( you're laughing now aren't you?)
Parts values and positions:
There are a lot of things than determine the voicing of the univibe variants:
Cap choice in the phasing stages. (both Neo and EZ use the same values)
Input caps. The Neovibe uses 1uf and the Easyvibe uses .001 !!!
LDR and bulb/LED choice and positioning. Color of LED and LDR light to dark range.
Then you get into opamp verses transistor etc etc.
Can anyone comment on the input cap differences Why would one use .001 and one use 1uf?
I wonder if that is a significant difference in why the Neovibe has more depth in the mid to low mids?
Hopefully this will give some insight into the differences between these two circuits
Thanks SteveB and tungngruv for your work on these builds.
SteveB's initial Neovibe recordings can be found at my website linked in my signature below.
(recommended)
John
That was a cool comparison of the two Vibes. Since I never heard an actual Neovibe I never knew how close the Easyvibe sounded. The Neovibe is stronger no doubt. Although I love my Easyvibe I would like to try a Neovibe at some point.
Does the Neovibe work at higher voltages? Is that light bulb it uses still available?
I think the Easyvibe isn't an actual clone so I didn't really expect it to sound the same. If I build the Neovibe I might redo my Easyvibe into strictly a phaser via John Hollis's instruction.
Oldrocker
Glad you got something out of the post, it took a fair bit of work... mostly by steveB and tony...
Yes, you can get the bulbs still. There are a few ones that will work. Radioshack has some as does Parts express.
I like the phase the most, I hardwired mine for phase only. In RG technology of the univibe I think it gives the specs for the bulb.
Should be an easy search if not. the Neo does use 18v I think as well.
If I can't get the Easyvibe on track with more depth of tone I'm thinking about building the Univibe clone at JC malliets site.
The layout is more "rubust" and as far as I know it follows the neovibe/univibe to the letter.
John
wow...
its...
the SWING of the univibe is in the NEOVIBE...
damn.....ok, so ill be building that hahahaha
Quoteok, so ill be building that hahahaha
You should. With a clean tone, playing through the neovibe is very enjoyable to listen to.
Thank you very much for this analysis. This very interesting, and even though I built a easyvibe, I guess I may have to build a neovibe just to compare them!
QuoteMy ears tell me that The Neovibe has a bit more sweep into the lower mids giving it a deeper effect.
More vocal into that "we-yow" sound as opposed to the Easyvibe which sound more like "we-you"
( you're laughing now aren't you?)
Not in the slightest.
The human ear is very sensitive to things that sound "vocal". And the differences between the "eee-ow" and "eeee-oooo" vowel sequences are quite distinct when you describe them interms of the resonant peaks that define them in the human vocal tract.
Translated into linguistics-speak, what you said was "the Neovibe produces a set of lower resonances which closely approximate a 'we-yow' vowel/dipthong sequence as opposed to the Neovibe's 'we-you' sequence. The resonance peaks are better spaced for this vowel approximation in the Neovibe than in the Easyvibe, leading to a more vocal-seeming quality of sound."
QuoteCap choice in the phasing stages. (both Neo and EZ use the same values)
This is a case where same values does not make for the same result. The easyvibe uses opamp phase stages which produce a more textbook allpass response. The Neovibe/Univibe is a less-than-perfect transistor stage that stamps its imperfections on the response. I suspect that you'd have to do more than tinker the caps to get them to be identical.
QuoteInput caps. The Neovibe uses 1uf and the Easyvibe uses .001 !!!
... Can anyone comment on the input cap differences Why would one use .001 and one use 1uf?
One uses high impedance opamp input buffers, one uses a much lower impedance transistor input stage.
QuoteLDR and bulb/LED choice and positioning. Color of LED and LDR light to dark range.
And this one is dead on!
QuoteThen you get into opamp verses transistor etc etc.
And this one is big, as I noted above.
The Neovibe is the Univibe, as closely as it can be made, and cleaned up a bit in some trivial details. The Easyvibe is, well, an easy approximation of the Univibe. It's right there in the names. :)
The resonance peaks are better spaced for this vowel approximation in the Neovibe than in the Easyvibe
Perhaps somethings could be done to the Easy Vibe lessen the comparitive differences...[making it less 'EZ' but keeping the 'easier to wire up' opamps] maybe use resistors to lower the input impedances ofthe opamps, and use a larger input cap?
Any ideas welcome...
I've been using the SS phaser with phase stage values for 'wobblier' sound [somewhere between Univibe and SS values]..sounds good. Still not all that Vibey though..it's holding the phaser position on my PB .. for the time being.
and what would it change if you choose different LED colors... let's say... blue, red, amber, green ? would that affect the sound ? Could choosing a brighter/darker LED make it closer to the neovibe?
Thanks for posting, John. Great assembly of information.
I built that one back in '96, & it has gone through some minor changes since then.
That bulb in the photo is a 12V 50mA, & I changed it to the recommended 12V 25mA a few months ago. The other bulb was still working, but I wanted to see what the sound of a bulb with a lower current rating was. I like the 25mA, but can't tell how different it actually is with doing an A-B test with the bulbs. I'd rather leave well enough alone :icon_wink: The film canister is also lined with adhesive backed foil now. I had the LDR's lying flat, facing up for a long time, but now, they are back as the appear in the photo, perhaps even closer to the bulb.
I changed the speed pot to the one that is available from Small Bear. Much better range spread throughout the rotation of the pot.
I lowered the resistance of the 2 side by side resistors on the LFO to get the speed faster. I just piggybacked some more resistors on top of the existing 2.2k. I measured, & it is somewhere in the 1k range +/-. Yeah, I'm lazy, but it it sounds like I want it....
I have a 10k resistor in place of the 4k7 that is connected to the base of the bulb driver. 47k was too subtle, & 4k7 was too choppy for me.
Once again, great work, John!
Steve
Steve
nice work on this comparison!! very informative. i have an easyvibe, and a microvibe, and i need to do some A/B testing w/ those two. i will eventually build the neovibe, and the voodoo vibe, i'm kinda a vibe junkie :)
Thanks for the input guys! I'm going to tey a couple things before I start on a Neovibe build.
Larger input cap, and more resistance to try and lower the impedance (thanks pete) Woulf that be adding resistance to ground at the input?
Add more resistance to the LED driver to get the LED dimmer to see what that does.
One thing that's fun to try is putting a pice of white paper between the LED/LDR to change what light the LDR sees. Try every other LED/LDR (thanks again Pete for that one)
The color of the LED can make a difference but I'm not sure it aplies here so much.
Cadmium sulphide Cds (most LDRs out there) are most sensitive to Green light
Cadmium selenide Cse (you can still find them if you look) most are sensitive to red light.
I would think this would be more of a case in a tremolo or stutter type device where you want a sharp on and off action with the LDR but it wil make differences here as well.
John
Yikes, typo alert!
What I meant was:
If I lower the resistance to ground would this bring the impedance down? Since the input is biased with 10M resistance would I just lower that 10M to ground and leave the other 10M , or lower both...say 100k?
I don't really understand the 9v to 10K before the bias 10Ms...
(http://www.hollis.co.uk/john/easyvibe.jpg)
If you want to lower the input impedance then lower the value of the 10M that's connected to the + pin of the opamp. The other 10M, the one that goes to ground is just a pulldown resistor so you can leave that one as it is.
The 10k resistor forms a sort of voltage divider along with the diode and the 2 LEDs to ground. The diodes and the LED set the bias voltage at about 3.5 - 4 volts and the 10k limits the current through them. Doing the bias voltage like this rather than by using a normal voltage divider using 2 equal value resistors means that as the battery voltage falls the bias voltage stays the same, because the diodes/LED combo drops the same voltage. This means that the circuit and especially the LFO will operate the same as the battery voltage falls.
Good info Slacker
Thanks for that explanation.
I overlooked the two 10M resistors being on either side of the cap. Not really bias there...
John
No trouble, nice sound clips it's an interesting comparison. After to listening to the clips though I have to say that my easyvibe sounds a lot more like your neovibe clips. It's hard to judge purely from sound clips but it certainly sounds more univibey than your easyvibe.
I guess there's a lot of variables in a pedal like this, not least the choice of LDRs and LEDs and how you attach them together. On mine I've just taped the LDRs to the side of the LEDs, so they're not light tight and the light from the LEDs is probably more diffused than if you attach them directly to the end of the LEDs. I don't know but I wonder if this replicates the neovibe's bulb better.
I have a modified version the the Easyvibe LFO on my site that I felt had alittle more "vibe" feel as well as a few added features. It mostly called for reversing the polarities of the LED.
It would be interesting to compare.
Andrew
Slacker
So with your LDR/LED set up with the LDR reasiong the side of the LED you get a good bit less light on the LDR. This goes along with rasing the resistance to the LED/Bulb driver and reducing the amount of light that hits the LDR. I'll have to follow through with this theory when I get my easyvibe back.
Tone God
So your LFO is set up to reverse the cycle of the LED? Is that what you meant by reversing the polarity?
John
Wow, this thread rocks!
Ok: my first impressions from listening were that I preferred the easyvibe over the neovibe for some reason. I think I preferred the tone of the Floyd song on the easyvibe better. However, it does sound to me that the neovibe has a bit more of a "yow" like Basicaudio said. I loaded all the files into winamp, popped them on shuffle and tried to identify which were which blindly after a while of listening. I was able to identify which song had the neo/easy on floyd. However, when the shuffle came to the Trower song, I had thought the neo was the easyvibe.
So I guess my impressions are that they are both awesome circuits, and in a live situation or a blind test, it'd take a great pair of ears to be able to say "thats a neovibe" or thats an easyvibe.
Nice soundclips, but I wasn't able to tell too much of a difference between the two that would warrant me pulling the plug on my current easyvibe project and doing a neovibe instead. I'll be honest. :-[ maybe my ears arent as good as others are.
Quote from: Basicaudio on February 22, 2007, 02:10:52 PM
So with your LDR/LED set up with the LDR reasiong the side of the LED you get a good bit less light on the LDR.
Yeah it reduces the amount of light the LDR gets, which changes the range of resistances it sweeps over. The other thing is that if you look at an LED from the side as it gets brighter and darker it looks a lot more like a bulb than if you look at it from the end. I don't know if it really makes a difference but it might be worth experimenting with.
Here's a picture of my easyvibe board. (http://www.eskimo.plus.com/fxstuff/easyvibe_pic.jpg)
Quote
Tone God
So your LFO is set up to reverse the cycle of the LED? Is that what you meant by reversing the polarity?
The Tone God's mods are here http://www.geocities.com/thetonegod/downloads/downloads.html (http://www.geocities.com/thetonegod/downloads/downloads.html)
Quote from: Basicaudio on February 22, 2007, 02:10:52 PM
So your LFO is set up to reverse the cycle of the LED? Is that what you meant by reversing the polarity?
No. The LFO still runs in the same manner as the stock version but by swapping the polarity of the LEDs to run on the other edge of the LFO's sweep it fit my tastes more. I also added a bunch of other features like the speed pot now only needs two connections and wider speed range.
Andrew
Very cool post John! That Neovibe sound kills!!!!
I don't think there are voltage differences great enough in any of the phase stages to meet a diode threshold, ie to introduce clipping.
Generally, 'clean' is the hard end of the stick to hold down, I suppose the idea is to keep opamps clean [because the rough OA clipping sound]. But there are many ways to dirty up opamps to sound more like tubes...rambling I know..
Just thinking there must be a way to trick opamps that'd normally be very clean..to dumb them down and give them more character.
I know the easy vibe is designed for low current consumption, but perhaps input impedances could be dropped to a more 'lo-fi' level?
Quote from: The Tone God on February 22, 2007, 03:00:12 PM
Quote from: Basicaudio on February 22, 2007, 02:10:52 PM
So your LFO is set up to reverse the cycle of the LED? Is that what you meant by reversing the polarity?
No. The LFO still runs in the same manner as the stock version but by swapping the polarity of the LEDs to run on the other edge of the LFO's sweep it fit my tastes more. I also added a bunch of other features like the speed pot now only needs two connections and wider speed range.
Andrew
Now, this seems interesting. While trying the EZ-vibe, my initial feeling was that it was backwards, but never could quite figure it.
John, it would definitley be worth a try when you get it back.
Steve
Two sheets to the wind, is just a bit too much damping, not enough intensity.
1.5 sheets is just right.
Adding two thicknesses of paper dulled it down too much, full setting = not enough wobbel.
with the LED's LDR's offset a slight, and a sheet of typing paper across all four [between the LED's and the LDR's] and another sheet between only two of the four...I moved the small sheet [covers about 2 LED's] around and hear the differences..my caps are in UniVibe order, one side dulled sounded different than having the second thickness of paper cover the right two.
I have a nearly light sealed box and a light breaker where the light doesn't come in much, since I'm not going for settings where the LED's go fully off much..I figure a tad of background light might be a good thing.
@@ Rate this mod was easy since I have the LDR's in one 'board' the LED's in another [components stuffed in cardboard stiffened with toothpicks], each opposing board is held in place with wire struts [basically they're kinda laced together], the sheets go right in there, make the intensity knob go less at max.
Running the LEDs off the opposite wave form seems interesting. I'm not sure what the waveform looks like but I assume it's not symetrical or else there would be no difference in the operation. Any one have a scope shot of the wave form?
tone god
Can you decribe what the difference is...does it produce a more vocal sound?
I need to study the schematic on your site more to under stand the differences.
Pete. It really depends on how each person made their board but the paper trick is kind of fun. basically sets different phase intesities per each phase stage (by varying light to each LDR)
John
I just got my Neovibe board from GGG the other day... this post couldn't be more timely.
Great job on the clips and starting the conversation on the builds!!
I would like to correct my previous statement: First time I was listening, I was listening on campus through 10 dollar earphones. Since coming home I gave them another listen through a better set of speakers, and I now can DEFINATELY hear that lower yow on the Floyd song I couldnt hear before.
I'm still going to continue on with my Easyvibe build. I guess that means I'll just have to build a Neovibe too!
Running the LEDs off the opposite wave form seems interesting. I'm not sure what the waveform looks like but I assume it's not symetrical or else there would be no difference in the operation. Any one have a scope shot of the wave form?
I was about to comment that TG's mod might be easier, especially with closed opto's or photo enclosures, until I saw your related comment.
The way I wired it has the LED Driver OA buffered...under the board with a wire soldered across the two socket pins, I'm thinking pull one leg like the output so it's outside the socket, quick solder [heat sink] to it for that connection.
tone god
Can you decribe what the difference is...does it produce a more vocal sound?
I need to study the schematic on your site more to under stand the differences.
...I'm trying to sort out what it does, it looks like the two LED's now on the V+ side of the LED Driver are on the other side of the LFO Signal so the LED's light two on one side, two on the other, thus 1/2ing how many led's are lit at any time [two at a time] and doubling the rate at which LED's are lit?...then the other mods are to compensate for the speed and the LED intensity...probably wrong but that's my theory I'd like to test, maybe it saves you time typing.
Pete. It really depends on how each person made their board but the paper trick is kind of fun.
It is pretty good, dampens the intensity [of which I think there's still 'just plenty], and moving it back and forth, the 'thick' cap [I believe...whatever] on one side the 1/2 sheet changes the sound a bit more than the other side..with the 'noise on [FF whatever] and not playing, there's even a big difference in the amount of noise rush associated with that part of the sweep...pretty interesting, and..it probably doesn't matter much what the papers say, I'm believing I can turn the intensity up for wobble with less tremolo like effect I was having, subjective results at best.
Not only that...the other EZ Vibe I had kinda going, and still have, it shut off sometimes I put a regulator on it, acted funny on the PS depending on venue etc., it was made from whatever Photocells RS was selling and red leds, and had something wrong with the pin voltages and all...that one had a deep sweep, lotsa wobble, this one's built with 'spec' parts and sounds more 'clinical'...of course I messed around with caps, that one was on a different voltage etc., had a 47k stuffed in because it caused the sweep to continue longer between power downs [I had a momentart switch to power down, made for really cool fading phase effect, thick sweep for about 15 seconds, no sweep after about 45].
Joelap and SLacker
Somehow I skipped over your posts the first time round, didn't see them.
If you set up the clips so you can go back and fouth you really can hear a good bit of difference in the vocal like sound in the lower sweep on the midrange not unlike a wah.
Setting up the LDR to read light from the side does make the LED look more like a bulb filament. Les light and a a pin pointed light at that.
Seems that a lower light situation is beneficial.
With any luck we can get the last 10% percent out of the Easyvibe and more toeards a NEO/univibe!
John
John, with the easyvibe you have on hand, theres those two 10k resistors that come together... I saw a mod in which you replace the two 10k's with say, a 5k or 8.2k, and place a 5k pot between them. That was supposed to make it so you can fine tune the sound. I dont remember exactly, but I remember reading it improved the sound. Is your easyvibe set up that way? Maybe you could try that out and see if you can choke out that last bit from that? Sorry for this post being vague, my laptop crashed three weeks ago and I havent had a chance to get my data off of it yet, so I dont have the schematic in front of me.
Yes, I have that in place now. The Build used carbon film 10% resistors so I figured I'd put in a trimmer to balance more accurately the phase between the original and phase shifted signal. I just put in a 20K trimmer pot and set it so both sides are exactly 10K. With metal film 1% resistors this wouldn't really be necessary. Plus I wanted to see how it affected the balance. Basically wet dry blend control. Not worth making it a panel pot though.
John
Quote from: Basicaudio on February 22, 2007, 06:29:18 PM
Can you decribe what the difference is...does it produce a more vocal sound?
I need to study the schematic on your site more to under stand the differences.
Due to the vanacular that we use around here it is hard to describe but it had a better "swing" feel on the ends I felt. I often use my vibes at higher speed and most vibes' effect get mushy and lost at high speeds. I can't comment on tonality changes since I did not use the audio portion of the easyvibe circuit but my own.
I don't have any scope traces handy since it was a while back when I did it but maybe sometime I'll get around to it.
Quote from: petemoore on February 22, 2007, 07:49:16 PM
...I'm trying to sort out what it does, it looks like the two LED's now on the V+ side of the LED Driver are on the other side of the LFO Signal so the LED's light two on one side, two on the other, thus 1/2ing how many led's are lit at any time [two at a time] and doubling the rate at which LED's are lit?...then the other mods are to compensate for the speed and the LED intensity...probably wrong but that's my theory I'd like to test, maybe it saves you time typing.
Correct to a degree. I swapped the LEDs from ground to V+ but I did that to all of them not just a pair. You could try going to a pair but I think the vibe sound would be weaken.
Andrew
I would like to give John Hollis's designs a credit or two. Hollis tries with most of his designs to use the least amount of parts with as simple as possible circuits to do the job. The Easyvibe is just that,.. easier to build than the Univibe or Neovibe and works off a 9 volt battery. If you really wanted to you could buy all the parts at Radio Shack. Many would find that useful. For what it is the Easyvibe is great alternative to higher voltage and more complicated phaser builds IMHO. It's not a perfect Univibe clone but for what it is it's a clever design. Having said that, at this point in my effects building I think I'm ready to try effects using different voltages with more complicated circuits and the Neovibe would be a good place to start. But I'm starting a new job soon and I won't have as much time so this may take a while. I'll order the parts and see if I have time to put a Neovibe together. When I'm done I'll try posting some clips.
John Hollis is da man. :icon_biggrin:
Well listening to the clips and not having a Neo or Uni...
And noting that the differences are well documented I think...
I have built two Easy Vibes, one from 'whatever' photo schtuff [LED/LDR], the other from 'high spec' photocomponents.
Besides the subjective and 'whether or nots', the 'whatever' vibe had a more earthy tone.
I can say put some 'lampshade' material in...this made quite a difference, IMCase, making the sweeps less 'clinical' sounding..it changes the way the sweeps...for one thing the intensity knob can be turned up more...@@ rate, after trying the photos with lampshades, no paper, 1 sheet, and 1.5 sheets [2 sheets] I chose 1.5 sheets, the .5 sheet being two thicknesses of typing paper which are like 'sandwich slices' between the LED/LDRs, and the 1rst sheet between all four photocombos.
I included inside the TB for the easyvibe, on the output, a bypassable Mosfet transistor to adjust level. Nice addition, adds a Mos-tone, also deepens the sound a touch, also allows it to drive whatever's next in line, perhaps the easyVibe doesn't sound quite as 'thick' or what compared to a Neo or Uni, it does sound excellent, and is easy like the name says.
I was about to make a mechanically movable .5 sheet lampshade, moved to the right side of the photosection, it enhanced the wobble, moved to the left side, it negated some of the wobble.
This thread inspired me to finish the neovibe I started last year. It fired right up and sounds great. The hang-up has been building the light box (I made a pyramid out of brass sheet) and finding a box to put it all in. I made the #1 input buffer on a daughter board but I'm still debating using it, sounds great without it but I haven't tried an active pickup yet.
I also went with the 120 ohm and 47k resistors on the light that was suggested in another thread.
I'm trying to add an actual on-off status light (not a LED) like on the original but keep frying resistors 1/4w and 1/2w aren't big enough, they cook up like hot dogs.
Just in order to have a better point of comparison I would have liked the sample #1 to be the same for the easy vibe as the neovibe one.
Too bad.
Anayway the sound of the easyvibe is very close to the Neovibe.
And it may not be obvious to make the difference between easyvibe and neovibe inside a mix !
Very interesting. It would be really cool to have a kind of library of these things. I wonder how the Phase 45 would sound with that setup?
You may want to save this post in the Wiki, you know, for posterity?
niko13
Although the easyvibe sounds nice in the clips i much prefer the smooth, deep vocal impact of the neovibe.
The easyvibe is to subtle for my tastes.
Remmelt
I'll try and post this in the wiki
john
Quote from: John Lyons on February 21, 2007, 10:01:46 PM
Member Tungngruv made the Easyvibe perfboarded here
(http://www.mrdwab.com/john/EZVibeperf1.jpg)
(http://www.mrdwab.com/john/EZVibeperf2.jpg)
If you haven't tried it yet, put heatshrink tubing around the LED-LDR combos. The sweep will become MUCH wider!
Reason being that ambient illumination, however minimal, may still affect the resistance of the individual LDRs...
Thanks for the tip.
I actually do have heat shrink and an end cap on the LED/LDR combos for the sound clips posted above.
The pics were the initiall build before totally finishing it up.
John
John,
When you shielded your LED/LDR combos did you keep them in the same position?
Quote from: John Lyons on May 15, 2007, 11:30:27 AM
Thanks for the tip.
I actually do have heat shrink and an end cap on the LED/LDR combos for the sound clips posted above.
The pics were the initiall build before totally finishing it up.
John
I learned the hard way. The two LEDs that bias the circuit were giving off too much light to make the 'dark' resistance reach its point... So I had to 'light-proof' them. :)
I am planning to do some mods to mine. Already have a volume boost and a dry-wet mix. Thinking about what else to do to it.
Constantin,
Actually you have only shielded the bias LED , not the LFO LED. Right?
QuoteJohn,
When you shielded your LED/LDR combos did you keep them in the same position?
When I built the above easyvibe, I took the picture before I wrapped each led/ldr in electrical tape. Didn't make a big difference in the sway of the vibe. I guess because the inside of the enclosure was dark enough. I have a neovibe now and it sounds a lot different (IMO) than the easy vibe, although both units sound really good in their own way.
Yes, the LDR/LED combo looks the same in the pic above as it does now. Same position...just has black tape around a drinking straw slid over them and a cap piece over the top. (tony came up with the drinking staw light shield while on a date with his wife...)
who says romance is dead?
John
Drinking straw ?
Clever idea!!
Tunggngruv,
QuoteI have a neovibe now and it sounds a lot different (IMO) than the easy vibe, although both units sound really good in their own way.
Could you be more precise because according to me listening to the samples there's not a big difference (especially on the Trower's Too rolling stoned riff) except the deeper sweep on the neovibe of course.
Read the thread again. All of this is gone over in the first few pages.
The neoviobe has a deeper sweep with a more pronenced vowel like sound. Not unlike a wah.
John
Yes I know John.
I just wanted to say that according to me the easyvibe doesn't sound "a lot different than the neovibe" (which sound is more organic). I mean the easyvibe has a good vibey sound even so.
The easyvibe does have a good "vibey" sound but not as much as the Neovibe. IMO, it really nails the Hendrix and Trower thing. I've had both and when you hear them live, the Neo is the one, although the easyvibe has a great sound, just not the amount of sway and vowel quality (as John stated earlier). Keep in mind this is just my opinion though.....
+1 Neovibe is superior
I've tried a number of dual opamps on Easyvibe and found the best combination, to my taste at least, is formed by a 4558 as the first and last CI's, TL062 as the second and the third CI's. I've changed the input cap too, I've used 1uF, poliester, NP.
I've included one more cap, .47uF, between the output of phased signal and the final mix.
I perceived a bassier sound and liked this way. I soon will post some sound clips, hoping it's not one more mojo factor question...
Hi,
Brand new to the site, was directed here by Steve from Small Bear. I am looking to tackle both of these projects and have a question about parts availability. What LDR's do you use for these units? Are they the same or does each circuit require a specific LDR? Can someone please send me p/n's?
Great sounding units. I noticed in the pics that the EasyVibe build did not employ the heatshrink to isolate the light source. Is it possible that this is affecting that depth of that unit?
Thanks for all of your help,
Kristopher
Small Bear has the LDR's you need, and in the descriptions of the LDR's on his website he recommends which ones to use for which crkt.
The LDR/LED combos on the easyvibe did use a light shield and heat or heat shrink on them, The pic was taken before this step.
The sound clips (in the first post) were made with fully light shielded LDR/LEDs.
John
Great sound samples. Good work.
I built an Easyvibe a few years ago. It sounds great. I have wanted to tackle the Neovibe but it's a step up in complexity.
As far as the Easyvibe is concerned I have always wondered about the Biasing. The bias used here seems sort of complex and touchy. Why was this designed like this? I'm talking about the two LEDs setting Vr.
Why could this not be biased in a standard way with a resistor replacing the two LEDs?
Another item that I do not understand is the purpose of the four 1n914 diodes? what are these doing?
Quote from: soggybag on September 18, 2007, 02:41:54 PM
As far as the Easyvibe is concerned I have always wondered about the Biasing. The bias used here seems sort of complex and touchy. Why was this designed like this? I'm talking about the two LEDs setting Vr.
The biasing is done like that so that the bias voltage stays constant as the battery voltage falls, if you did it using a voltage divider the bias voltage would fall as the battery voltage fell. I think this is so the performance of the LFO remains the same at different voltages.
Quote
Another item that I do not understand is the purpose of the four 1n914 diodes? what are these doing?
I've never really understood what they do either. I think they'll clip the LFO signal if it goes more than 1.2 volts above or below the bias voltage. The LFO signal is triangular so I guess clipping the top and bottom off the waveform makes it more like a sinewave?
From what I understand, they shape the LFO waveform as you suggested. I assume that they change the waveform from triangle to a more sine shape. As a mod on mine, i wired up two diff pieces of perf, one w/ 2 diodes, one w/ all 4, and put a switch to toggle between them. neat mod I think. The 2 diode version has a mellower vibe to it. I should try an asymmetrical setup to see what that sounds like... :icon_question:
Quote from: slacker on September 18, 2007, 03:16:40 PM
The biasing is done like that so that the bias voltage stays constant as the battery voltage falls, if you did it using a voltage divider the bias voltage would fall as the battery voltage fell. I think this is so the performance of the LFO remains the same at different voltages.
Quote
This makes sense.
I built one a few years ago and after some debugging I found that it would not work if the two LEDs setting the bias were not the same type as the other four paired with the LDRs. I've never understood why this is.
Quote from: snoof on September 18, 2007, 12:09:19 PM
Small Bear has the LDR's you need, and in the descriptions of the LDR's on his website he recommends which ones to use for which crkt.
Thanks for the reply. Steve @ Smallbear says that the Clairex p/n he used to stock for this project went the way of the dodo. He does have LDRs listed (for Neo Vibe) and says they may work but he cannot guarantee it. Any experience here using those for the EZ? Any other p/n's or sources? Any and all help is appreciated.
Thanks,
Kristopher
Uh oh
If anyone knows where to source that part let me know... after listening to these samples I have to get a Neovibe going.
--Brad
Quote from: Solidhex on September 20, 2007, 03:54:22 PM
Uh oh
If anyone knows where to source that part let me know... after listening to these samples I have to get a Neovibe going.
--Brad
The LDR's that Small Bear sells are for the NEO vibe... you can get them there. I am looking for the Easy Vibe photocells.
Just a thought, maybe an LDR would respond better to a white LED like it would from a lamp. Also, I don't see the need for 4 LED's. One LED could be used and arranged like a univibe.
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.
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).
EDIT: whoops, I meant to post this in the other thread: http://www.diystompboxes.com/smfforum/index.php?topic=61005.0 (http://www.diystompboxes.com/smfforum/index.php?topic=61005.0)
Quote from: John Lyons on May 15, 2007, 02:00:40 PM
Yes, the LDR/LED combo looks the same in the pic above as it does now. Same position...just has black tape around a drinking straw slid over them and a cap piece over the top. (tony came up with the drinking staw light shield while on a date with his wife...)
who says romance is dead?
John
How would you secure a straw to the board? Nice idea - just trying to picture it in my head.
The electrical tape covered straw (light shield) doesn't connect to the board.
The LED/LDR combo fits into the straw snug enough to stay put.
The straw slides over the combo, if you wanted to you could glue it all together by filling the straw top with glue, no need to though.
john
Quote from: jaytee on September 23, 2007, 03:43:36 PM
Just a thought, maybe an LDR would respond better to a white LED like it would from a lamp. Also, I don't see the need for 4 LED's. One LED could be used and arranged like a univibe.
Sorry to revive such an old thread, but I was thinking the same thing. Why not use one clear super-brite LED with the 4 LDR's arranged around it like in a univibe. Cover the whole thing too.
One thing to keep in mind is that an LED has a specific "viewing angle" where as an incandescent bulb emits light from all angles.
If you sand an LED's case with 400/600 grit sandpaper you might be able to get enough viewing angle for LDRs placed around it
but the main viewing angle is with it pointing straight on.
With a reflective light shield and the sanded or bought as frosted LED you would get the best result I'd say.
John
N.B.
A cavity which is mirrored entirely on the inside effectively mixes light to a uniform level everywhere inside. That's why the original used a shiny cap and up-pointed LDRs - the light was uniform-ized by the shield, if imperfectly because one side was not mirrored.
You're right, John. The "super-brites" especially, are only "super bright" if you are looking at them dead-on, perpendicular to the base. But if the inside of the light box is reflective, as R.G. mentioned, it may not matter that much what angle the LDR/LED are oriented to each other.
I think it's time for me to get busy playing with this and build one. I've had the PCB for years. Time to order parts... Thanks! :icon_wink:
I recently read that the Danelectro Chicken Salad is fitted with surface mount RC4558 opamps.
Did anybody already use them in an Easyvibe build? Would swapping the TL062 opamps of the Easyvibe stock version with RC4558 affect the tone a lot?
As I posted earlier at this same topic I did it on the first and the last IC's. I did other small mod's and liked the results. I would sayI perceived a small but positive change in the overall sound.
Thanks Alex,
It's been a long time since I didn't read the whole thread.
Does the easyvibe sound more analog (warmer) with 4558?
I think so, but just a bit more.
It is not exactly like an Univibe, not so "vocal", as someone posted here, but very good anyway.
There's something i just noticed on Tungngruv's easyvibe (the top picture on the previous page): the LEDs used are 5mm (instead of the 3mm ones suggested by John Hollis).
Does this use of 5mm LEDs give a good improvement to the sound? Did anybody ever compare changing the LEDs size?
There should not be any difference really.
The 5mm LEd would be easier and more efficiently
light up the LDR though I would think.
The 5mm LED matches the size of the LDR more closely...
john
QuoteInput caps. The Neovibe uses 1uf and the Easyvibe uses .001 !!!
... Can anyone comment on the input cap differences Why would one use .001 and one use 1uf?
One uses high impedance opamp input buffers, one uses a much lower impedance transistor input stage.
I increased the input cap to 0.1µF and find the sound fuller. I think (as Alex Frias did) it's worth a try to increase this value again: the input cap in the Danelectro Chicken Salad is 2.2µF and it has a really good wobble.
Quote from: John Lyons on February 21, 2007, 10:01:46 PM
Easyvibe vs Neovibe
(http://www.mrdwab.com/john/Tweedvibe.jpg)
I rehoused the easyvibe in and oak box with tweed covering
John
That tweed casing!!!!!! What a beaut!