Here's a collection of vero (stripboard) and tagboard guitar and bass effect layouts that we have put together covering many classic and popular effects in growing numbers. Many of these have been posted on freestompboxes.org, so check that site out for great discussions on building your own effect pedals. Enjoy the builds and please also visit us on Facebook and Twitter
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Sunday, 29 January 2012
Bigfoot FX Magnavibe
I'm bored of dirt layouts (until the next one!) :o) Check the notes on the LED/LDR
Finished mine yesterday; I used a VTL5C1 (I got some cheap from an overstock place) and it works great. But just playing around with various LED/LDR combos got nearly the same range. Ultimately, a 3mm diffused red LED and one of the larger diameter LDRs works almost the same. Perfect for that Shine On You Crazy Diamond opening riff sound.
Just finished this, Very cool. I have a Dunlop Uni Vibe (borrowed) and this stands up really well to it. I used a 1m LDR and a standard red LED... first ones I tried and sounds great so I'll stick with them ;o)
I wouldn't have thought so mate. The fact they've told what the viewing angle is suggests they're talking about the indication LED. Plus he doesn't go into any technical detail about anything else so it's unlikely he's telling the spec of an internal component.
My first post here, so I have to say thanks for all the hard work!
I had some spare LDRs kicking around, so I had to give this one a go. It took some tweaking of the LDR/LED combo to get it working properly, so I used a piece of McDonald’s straw wrapped with electrical tape to make a light shield for testing purposes. On reflection a Burger King or KFC straw might have been a better fit as the McD’s diameter is slightly too large. Ended up with standard 5mm red LED, with the top of the LED aimed straight at the LDR. Sounds great!
I built this and it works, but I only really hear it "vibing" after about 8-9 on depth. I'm using a photo-resistor with a Light resistance min/max of 5k-20k and a Dark resistance of 20M coupled with a 5mm Yellow LED (seemed to give me the most "vibe", but that could be subject to having messed with several of them and getting a little de-sensitized).
Can anyone recommend some different values that might give me more range in the Depth of the Vibe? I did try a red led and it was pretty close to the same as the yellow.
I'm not sure that the LDR value is critical. I just bought a few on eBay for another project and used one of the leftovers for this build.
It took me a while to get it working properly. The first problem was that I didn't think about the effect of background light when I was testing it. The LDR needed to be kept in the dark for it to detect the variation in the intensity of the light from the LED correctly. I made a light shield with LED experimentation in mind but any method of covering the LED/LDR would do. It's probably not an issue once the pedal is in an enclosure with the lid on but it stopped mine working while testing in the open. The second thing I found was that I had to bend the LED leads so that the top was pointing directly at the LDR, as the light from the side of the LED wasn't bright enough to get the full depth of the effect. So it was all about getting the light and dark right. If it's any help, it was really obvious when the effect started working as it should.
I hope you get it sorted now. Shielding the stray light helped with mine but bending the LED and top of the LDR so that the top of the LED pointed directly at the sensor of the LDR made a huge difference.
Thanks, hh. Even boxed, though, same thing. I'm going to try out a few more led+photoresistor setups and maybe even a premade optocoupler and see if that helps.
This is a nice mellow univibe,and the first pedal I've tested in the dark ! Used an ultrabright blue LED and pointed it straight at the LDR about half a millimetre away for the best "swampy" effect.Veeeeery noice !!!Thanks
Finished this pedal today. This is a hidden gem. Not quite a trem - not quite a vibe. We used to have a vibes player named Jon Metzger play at a restaurant I worked at in the late 80s. This gives your guitar that vibraphone sound. Not that horrible seasick warble-y sound ( yes, sometimes I like that too ) - kinda a tremolo and uni-vibe combo.
Madbean has a couple of resistor values to change at FSB for a little more speed control but this layout is fine as is ( I'll probably build another with the Madbean changes to see if I can get a slightly slower vibe too tho' ). I will be building this as Christmas presents for close friends who don't know what they're missing. I can't stop playing with this on.....
I just finished this one, big volume drop engaged, but there is a very subtle vibe there. I used 2n2222 tranny's though, would that cause my volume drop? I have a few more LED's and LDR's to mess around with to get a proper vibe from it.
No volume drop at all on mine. I just looked up the data sheets on the MPSA18 vs the 2N2222. the hfe on the MPSA18 shows up as between 500 and 1500 ( mine have usually measured around the 900-1000 mark ). The gain of the 2N2222 is only about 100 to 300 hfe so I would imagine that might be a factor in the volume drop. Did you socket the trannies so you can swap?
I will say that I used a 10K to 1M LDR so my vibe is just a tiny bit less intense than the demos that I have heard - not a big deal since I still find myself turning down the depth a little as is. I have a 20M LDR that I will swap out to see how big a difference it makes though, just out of curiosity.
Also, I think someone already mentioned earlier - make sure that the LED is pointed directly at the LDR and either in shrinkwrap or black electrician's tape ( I used tape because I was out of the proper size of shrinkwrap and it worked fine - just not as pretty...).
I'm a bit confused about this, it only seems to work right for a second after I pull the power. Grounding problem? it's in a plastic enclosure with no switch, I still haven't got the mpsa18's I suppose that could be it?
It's fixed! Working perfectly now, when I went to socket the new trannies it turned out I had one of the old ones in the wrong way round. Really nice effect, I just need a decent enclosure and a switch to go with it now. Thanks
I've rebuilt this two times, but, I've got a pure clean sound when I play it... I've checked the orientation of the MPSA18, and everything seems ok, can someone help me with a picture of its build?
hopefully you can see these. https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-ash3/942207_320652808062254_1012549100_n.jpg https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-ash4/302948_320652538062281_401525405_n.jpg
If you don't have the led/ldr enclosed in something like shrinkwrap or electrician's tape ( so no outside light can get to it, it won't work ( unless you're testing in a dark room or you have it in the enclosure so no light can reach the pair ). Is outsode light getting to it when testing?
Glad you got yours sorted out, Bill. Do you know what value your LDR was?
Hi, I've finally my vibe working, but LFO is really noisy, anyone has the same problem? Any solution? I've a 'ploc' when I switch pickup. Thanks in advance.
I built this and could not get the affect working. I tried a few VTL5Cx's. The circuit and build all looked Ok. I Finally found the culprit, a single metal strand quite invisible from the Input Wire connection was touching that side Link. As soon as I removed this and tried another VTL5C1 this time it worked fine. Mystery solved. Such is Pedal Building. LoL.
This one's a sleeper. Built this with a optoisolator, the results are exactly like in the youtube demos. Very unique sound, gonna try and fit this into my band's sound. Getting a little tired of fuzz/OD stuff so I guess I'll try out some more modulations next. Already did a Phase 90 and it turned out well.
just an fyi for you guys- when you put pedals into enclosures you are not getting complete darkness if you have an LED installed. the small amount of light that comes off the bottom of LED's can easily light up a dark enclosure pretty well. it affected my clarinot after I boxed it!
Thats interesting and important to know, I've often wondered if there is enough light contamination to affect ldr based circuits. Was the difference quite noticeable when you addressed the problem? Thanks Dave
If you put the LED and LDR, facing each other, into a short length of shrinkwrap, they are pretty well isolated from any external light. It has worked in all of my pedals.
I built this and it sounds great with a number of different LEDs. Very cool effect- thanks for the layout. However, I feel like I'm not getting it as slow as it is on video demoes ive heard. Everything is working properly- it just doesnt get very slow. Got any suggestions for getting my slowest speed slower?
I too would be interested to know which resistor or cap change would possibly slow the speed a bit more when the speed pot is at zero rotation. Thanks in advance.
Well, the speed thing has me concerned. I haven't built this yet, but in concern for the speed issue, I went ahead and ordered the VTL5C1. Oh well, the pain of poor craftsmanship far outlasts the joy of low price....or something like that...
That said, if you are looking to get it slower, the 2k2 resistor and the 1u capacitor that go from speed3 lug to the LED look promising for sockets and adjustments....
This has been on my board since the day I built it and I'm keeping it! One thing bothers me though, it boosts treble frequencies a bit. This is annoying when I'm purposely using dark sound for certain passages. Any ideas how to counter that without interfering with the circuit too much?
glad you like yours. I gotta ask are you able to get a decently slow rate? My speed knob does not change the speed from like halfway up to all the way down. It really just goes from moderate fast- to pretty fast. I also dont get much use out of the depth knob, but i think that may just be my LDR. What did you use for your LDR or did you use a vactrol? if so, which one?
works perfectly and i absolutely love it, wanted to share my findings about used optokopplers: VTL5C1 works ok, tried a VTL5C2 and it sounded noticeable better, deeper, more wobbly, mor like Tim Lerchs demos, (VTL5C4 did not work, no depht), what i finally installed is a white 5 mm led (blue, green, red no good) and a LDR 70k-200kohm (Musikding Germany order # foto70-200), put this in some heat shrink tube - i think that sounded even better than the VTL5C2
Just got couple of these together with VTL5C2s, and the speed range works - although to me it is a bit too fast even on the lowest setting. I'm happy with these builds for now, but if i'm going for another one at some point, i might try to halve the speed with 2µ2 caps instead of 1µ. Just a hint for those who feel the slowest speed is too fast... Actually these are parts of my "Aliupseeri Päärynä" experimentations.... :) +m
I though about those caps and what would happen to the speed if I altered them but didn't bother. Would that alter the whole sweep as in also lower the maximum speed available? I actually love this on full speed. Pair it with a subtle full speed phaser and you've got a very believable leslie sound!
That should cut the whole range to half... I'm thinking about replacing the whole LFO with something a bit more versatile. The main circuit is pretty ingenious in its simplicity and one should be able to use almost anything as an LFO for driving the LED... +m
That's true. The differences are just huge. VTL5C1 was smoother but also a little too subtle compared to C2. Now the C2 is deeper and wobblier but also a little bit choppier and it doesn't get as slow. Well. I use it as a pretty mild effect with a fairly fast speed so I'm perfectly happy with the C2. Endless room for experimentations with the LFO+LED combo so I won't even start 'cause I know it won't end. Ever. :D
Alright, I can confirm that VTL5C2 sounds a lot better than VTL5C1. Much deeper, smooth and pronounced effect. More vibe-like, definitely. I also put a 220k trimmer in series between the switch and input to lower the output a little bit. It boosted my amp and made the trebles shrill. Now it's set somewhere around 100k and sounds magnificent. Also doesn't change the volume level. Couldn't be any happier with this :)
I ve built this one and sounds really good, i d like to know if this could be modified to turn into tremolo with a switch, i read somewhere that magnavibe has lots in common with a ROG project, and that ROG , was looking similar to the EA tremolo, so if they two could be combined, this would be awesome. From vibe to trem through a footswitch. Thanks for the layouts!)
I was sure I had left a reply, but I can't find it! Well, my experience with the magnavibe / tremolo from giudis posted link at fsb is that the trem is not as good as the vibe, vibe keeps sounding so good, although. So I would recomend different builds for va tremolo, what a pity, since changing from a clean vibe to fuzz trem with the same tempo would be so great!
The LFO is exactly the same as the one used in the EA Tremolo, so it may be something that you could cobble together the two to share the same LFO and you could always add switching to select between vibe and tremolo mode so the tempos are in sync.
Ok, I¨'ll eat my words now. I'm back to VTL5C1. It's better, especially with a few mods. It makes sense too. It's 1M vs 50M dark resistance. Change the 1k8 resistor for something around 800 ohms (any less will make the speed faster) and change one of the 1u caps for a 2u2 for a little slower speed. Now this things sounds just amazing. I slowed it down even more but actually, it sounded very bad. It started to go very choppy like a tremolo. It would need a modulation of some kind to work with just a slow speed. The 2k2 resistor connected to the speed pot can also be subbed to adjust the speed. The problem is that the more you cut the speed, the more you lose that lovely wobbly vibe sound and start to sound like a bad tremolo.
I've just built this and tried various options. I ended up with the C2 which I found to be more pronounced (although I think slightly faster). I'm waiting for some LDRs so I can try them out to see if I can find a better option. I agree with you regarding the 1k8 resistor - I settled at an 820R value. I also changed the 2k2 to a 1k5 but ended up retaining the 27k resistor in parallel with the speed pot as it lost the slower speeds. I the next build I am looking at the three 1uF caps to increase to possibly 2u2 to help slow the vibe (I'd already soldered the 1u caps in place so missed the opportunity with this build). Despite all this, it could still do with a little more depth, especially at the slower speeds (unless I've done something wrong with this build) But it is still a nice sounding pedal - I just need to box it now once the paint has hardened.
I soldered my electrolytics off and put mounts in there. One 2u2 replacement is definitely better than stock, two subs starts to be a little meh and three 2u2 caps just sounds bad. I don't think the design handles such low speeds very well. Unless you like a choppy in your face tremolo-style vibrato. Many people like that too so everything's worth a shot!
Thanks Myrkky. I'd read a little bit about LFOs and most diagrams I saw showed the 3 caps with the same value. I suppose I shouldn't assume and have a test like you. Which one was the best to sub? Another though crossed my mind last night - I didn't play with the transistors. The gains in my build were about 620hfe, maybe I'll try a higher gain in the 'effect' position - not sure but might increase the gain a little. I also tested the LDR/LED before playing with the resistors - might have another bash and try a higher value for the 27k while I'm at it again
I've done some more testing since getting a few more LDRs
I kept the changes previously made to the 1k8 - reduced to 820R, 2k2 - reduced to 1k5, retained the 27k parallel with the pot. I also changed the transistor in the audio path to a slightly higher gain (but I didn't seem to notice a difference to the depth) (hfe = 770)
I made a little test rig out of a plastic pill box (painted the inside black) covered it in black tape, and used the bottoms from LED clips as spacers and some blue-tac.
I tested the Vactrols, Tayda LDR, GL5506, GL5516, GL5528, GL5537-1, GL5537-2, GL5539 and GL5549 I used LEDs - red, yellow & green diffused - red, yellow, green, blue, white clear I tried them at 10mm, 6mm and 1mm
The combination I found to give me the best sound (particularly at slow vibe which is what I am after) was the GL5528 with red 5mm diffuse LED at 1mm from the LDR. :D
Now to box this thing before I wreck the board anymore and I can get on with another build. Maybe next time I'll change the capacitor - just getting a bit impatient now
got mine working after I swapped the LED! first red 3mm led i tried did nothing, second one was very subtle, and then tried a white 3mm led and it works great. Still a pretty subtle effect even maxed out but sounds great!
You can use the split N blend. I wish I head read that comment before I built this tonight! Anyway, it sounds great. Most of the settings are unusable because they are so fast and deep, but the subtle settings are very nice! But yeah, I might just have to add a split N blend to this one. My Boss Bass Chorus has a blend knob and it is worth its weight in gold.
Built this and boxed at last. However when I connected the power I got a high pitched (low level) oscillation (squeal) which wasn't there before. Checked everything, moved some wiring, but no change. In case anyone else gets this, I solved it by placing a 100R resistor in series between the DC+ on the power socket and the power lead to the board. Its now quiet as a mouse and the effect is loooovely and swishy.
I'm having the same issue Dudave had(no guitar signal is passing but I can hear the sweeps from the LDR) I have checked all I can think with the multimeter and nothing. I am curious if there is an obvious issue others had and corrected. Dudave said his now works but without what the prob was. This is driving me nuts.
Mine worked fine first try. I've used a combination of LDR 5-20K (light) 20M (dark) (type9203) and a 5mm Red led (bright version).. really enjoying this one.. and also the first pedal I tried on the bench with the lights out ;)
I tried replacing the ldr/led for a vtl5c3 I have, but it did the same thing. Loosing a lot of the high end as well. Seems to be the ldr, cause with the ldr leads touching each other i get normal sound, with no effect. Everything else is working, the speed and depht are all fine.
I just bought one of these pedals already built. It sounds pretty good. There is on optoisolator in the pedal instead of the LDR. I ordered the LDR & LED's you guys recommended along with a vtl5c2 to see what I am missing, if anything.
Anyway, I like the pedal but it has a lot of hiss when it is engaged. Do you guys have any idea what could be causing this and how I might be able to control it?
Lo arme hace un par de meses y anda muy bien tal cual esta, use ldr y led rojo difuso.. algo a tener en cuenta es el transistor, con 2n5088 funciona exelente, con mpsa18 no me gusto.
I've just built this today and cannot get a sound from it at all. When I turn the speed and depth pots sometimes the LED pulses and other times it doesn't. Then when I engage the effect I get an oscillating noise through my amp, but no guitar signal. I've tried 3 different LEDs - 2 5mm and 1 3mm all different colours and no success. Has anyone else had this problem?
Spent an hour on this again today and I think I've figured it out! I've changed the LED (for the 6th time!) for a clear lens 5mm red, changed the cap that is linked to the LED for a 2.2uf and changed the 1k8 for a 680r and the 2k2 for a 1k8. The transistors I settled on were a 2n2369 in the first position from the left and an MPSA13 in the second position. I'm really liking the lush vibe tone from this now!
I just finished building this and the effect is very very subtle. I can hear the speed change as I turn the knob but the actual 'vibe' effect is extremely mild. I'm trying to diagnose what is wrong with my build. I have tried both a VTL5C2 and VTL5C1. -Do both of the ground points in the diagram need to be connected to ground? Or just one of them? -Does the polarity of the optocoupler matter? There is no polarity shown in the diagram so I assume no?
Both ground points on the board need to be connected to ground.
The polarity of the LDR does not matter but the polarity of the LED portion of the optocoupler does matter
If the effect is still to subtle after you're sure that the board is grounded correctly and the optocoupler is installed correctly, you may want to try out some different LED/LDR combinations to get the best sound
I used a waterclear blue LED and an LDR with a very wide resistance sweep. Can't remember the LDR model number
Built this one a while back,and it's a lovely effect. That said, I think it should be pointed out that it's not a true vibrato ie. it is not modulating the pitch
You could add a second LED in series with the internal LDR LED. At the moment you have one side of the LED connecting to Depth 1 & 2. You'd need to take that wire to the external LED you want to use, and then take the other side of that LED to Depth 1 & 2. Make sure you keep the anodes and cathodes in the correct orientation.
second question, any verified alternatives for the MPSA18, they're currently out of stock. BC550C's are available and quite cheap, but I wondered if they will work well before i order them
So this is a weird one... I built this, and it works and sounds great. So thanks for that! But when boxed up, I am getting a tremolo (variation in volume) with the effect off, and it is as controllable as the vibe when the pedal is on. It is actually a nice effect, and was obviously because of the way I wired the ground. So I wired the box so that all of the circuit grounds go through the switch, so when the pedal is off, they aren't connected. Well this worked, except now I have a huge pop on the footswitch, I think because I am turning on and off the LED running the effect. I tried a 2.2m resistor from input to ground, but it didn't make a difference. How are you all wiring up this pedal to not have these issues?
I'm super happy with the build, all works as it should. I'm keen to hear where people ended up with slowing the speed? Was it just changing one of the 1uF to a 2u2? Or was it changing all three of them to a 2u2? Cheers
Hello, the circuit works very well, nice and soft warm vibrations! I use it with my analog synthesizers. I bought a rotary switch (4 poles, 3 ways) and so I can switch between normal, slow and fast. For quick use, use 470n instead of 1uf (I changed two from the 1uf). In addition, I set a B10K potentiometer between 100N and the LDR to achieve a tremolo effect, instructions are available on the Internet. Great job, thanks for posting!
Change 100nf capacitor value for more or less modulation. 220f gives more modulation, 10f give very mild modulation.
2. Faster of slower effect.
Change the 1uf electrolytic capacitor for a larger value to slow the speed of the effect, or a smaller value for more speed. You only have to change the 1uf that is in direct contact with the LED.
You can add a switch in place of the 1 uf to switch between different values for a slow/fast switch. For example, 1uf for fast and 4uf for slower. You can use different values, or just switch multiple 1uf caps in parallel. example: 1uf + 1uf in parallel equals 2uf. 1uf + 2uf in parallel equals 3uf. etc.
3. Turn vibrato into tremolo effect.
Change the 100n capacitor for a resistor to turn the vibrato effect into a tremolo effect. between 1K and 20k ohms work, 1K being very very exaggerated effect (more like a heavy volume swell) and 20K give very very mild tremolo effect. I find 10K ohm to be a perfect.
Change the resistor for a 10k or 20k linear pot. This allows you to change between very heavy and very mild tremolo effect. Any higher than 20K and the effect goes from heavy tremolo to dry guitar signal. 20K is hardly any vibrato anyway. The pow will set the tremolo’s intensity.
The depth and speed knobs are shared between tremolo and vibrato. Depth is more a “mix” knob.
4. Add switch for vibrato AND tremolo effect in 1 box.
You can take out the 100n capacitor, and add wires in place. Connect these wires as the in and output of a on/on switch. Add 100n (or value of your choice) to one side of the on/on switch, and a resistor of choice to the other side of the switch.
This allows you to switch between vibrato and tremolo
Change the resistor for a 10k or 20k linear pot. This allows you to change between very heavy and very mild tremolo effect.
The speed and depth pots are shared for both effects.
5. Tremolo, vibrato, chorus switch.
Use a on/on/on switch.
Add the 100n cap to 1 position for vibrato. Add the resistor or tremolo pot to the other position for tremolo. Add 100n cap AND a 50k resistor in parallel for chorus.
I tried a 50K resistor which works fine. The chorus effect isn’t very strong but its a bit different that just vibrato.
NOTE!!!
The mini switch pop’s when switching between tremolo/vibrato/chorus. Haven’t been able to resolve this unfortunately.
6. You can add a LED in parallel to the LED that is connected to the LDR, this led acts a speed/depth indicator. I think you could use this led as the fx on/off led.
Hi, built it, it works, but vibrato is very weak, i can hear it a little bit on the max pot value, tried 1m, 5m ldr, changed led - not much difference, transistors are mpsa18, can anyone know what do with this?
Hey I know this is an old one but wondering if anything can help! Having an issue that's got me very confused. I am getting clean signal in bypass as well as when the effect is switched on, I have the LED showing when on but no effect. The LED/LDR combo responds to the depth knob, but it stays consistently lit regardless of the Speed setting.
I'm guessing the issue is around the Speed potentiometer but I'm unsure where to start. I have used audio probes in the past but if the signal is passing through fine I don't know if that would even help. Any ideas on where to start with troubleshooting?
Hi IvIark!
ReplyDeleteIs it verified?
What ldr I should use on it?
thanks so much for your wonderful layout :)
It isn't verified yet, and someone on FSB mentioned that an LDR with the biggest swing sounded best, so maybe one of the 5K - 20M ones would be best.
Deletethanks man, I always buy everything on Musikding, here there is the ldr list...
ReplyDeletehttp://www.musikding.de/index.php/cat/c82_Photo-Cells.html
can you help me in the choice of LDR?
the value that you have advised has too big range for those....
many thanks again!!!
Not too sure about those. This one has 1M dark resistance, but the light resistance looks quite high:
Deletehttp://www.musikding.de/product_info.php/info/p709_Photo-cells-24k-72kOhm--1M-.html
Here's a couple of options on eBay:
20M dark:
http://www.ebay.co.uk/itm/300544060822
1M dark:
http://www.ebay.co.uk/itm/120689977478
They seem cheap enough
Finished mine yesterday; I used a VTL5C1 (I got some cheap from an overstock place) and it works great. But just playing around with various LED/LDR combos got nearly the same range. Ultimately, a 3mm diffused red LED and one of the larger diameter LDRs works almost the same. Perfect for that Shine On You Crazy Diamond opening riff sound.
DeleteThat's great, thanks for verifying
DeleteJust finished this, Very cool. I have a Dunlop Uni Vibe (borrowed) and this stands up really well to it. I used a 1m LDR and a standard red LED... first ones I tried and sounds great so I'll stick with them ;o)
ReplyDeletehttp://www.bigfootfx.com/
ReplyDeleteThe info says 'LED is 45 degree yellow clear'. Do you think that refers to the LED coupled with the LDR?
I wouldn't have thought so mate. The fact they've told what the viewing angle is suggests they're talking about the indication LED. Plus he doesn't go into any technical detail about anything else so it's unlikely he's telling the spec of an internal component.
DeleteMy first post here, so I have to say thanks for all the hard work!
ReplyDeleteI had some spare LDRs kicking around, so I had to give this one a go. It took some tweaking of the LDR/LED combo to get it working properly, so I used a piece of McDonald’s straw wrapped with electrical tape to make a light shield for testing purposes. On reflection a Burger King or KFC straw might have been a better fit as the McD’s diameter is slightly too large. Ended up with standard 5mm red LED, with the top of the LED aimed straight at the LDR. Sounds great!
I built this and it works, but I only really hear it "vibing" after about 8-9 on depth. I'm using a photo-resistor with a Light resistance min/max of 5k-20k and a Dark resistance of 20M coupled with a 5mm Yellow LED (seemed to give me the most "vibe", but that could be subject to having messed with several of them and getting a little de-sensitized).
ReplyDeleteCan anyone recommend some different values that might give me more range in the Depth of the Vibe? I did try a red led and it was pretty close to the same as the yellow.
Thanks for any suggestions.
I'm not sure that the LDR value is critical. I just bought a few on eBay for another project and used one of the leftovers for this build.
DeleteIt took me a while to get it working properly. The first problem was that I didn't think about the effect of background light when I was testing it. The LDR needed to be kept in the dark for it to detect the variation in the intensity of the light from the LED correctly. I made a light shield with LED experimentation in mind but any method of covering the LED/LDR would do. It's probably not an issue once the pedal is in an enclosure with the lid on but it stopped mine working while testing in the open. The second thing I found was that I had to bend the LED leads so that the top was pointing directly at the LDR, as the light from the side of the LED wasn't bright enough to get the full depth of the effect. So it was all about getting the light and dark right. If it's any help, it was really obvious when the effect started working as it should.
That might be it then, as I haven't boxed it yet. I did use some shrink tube around it, but I doubt that made it as dark as it will be in a case.
DeleteThanks for the tip!
I hope you get it sorted now. Shielding the stray light helped with mine but bending the LED and top of the LDR so that the top of the LED pointed directly at the sensor of the LDR made a huge difference.
ReplyDeleteGood luck with it!
Thanks, hh. Even boxed, though, same thing. I'm going to try out a few more led+photoresistor setups and maybe even a premade optocoupler and see if that helps.
ReplyDeleteHi, i've wired that vero, and it doesn't sound at all.
ReplyDeleteI used a 1M Dark resistance LDR,
i only have the sound of the LDR...
I think that can come from the jacks...but not sure..
I've done lot of effects before, and never had those kinds of problems..
Have you ever tryied the jack which came from tayda?
3 pedals i've mounted with, and 3 fails..
Kind Regards
David
This comment has been removed by the author.
DeleteThis comment has been removed by the author.
DeleteThis is a nice mellow univibe,and the first pedal I've tested in the dark ! Used an ultrabright blue LED and pointed it straight at the LDR about half a millimetre away for the best "swampy" effect.Veeeeery noice !!!Thanks
ReplyDeleteCan you post a picture of your pedal? ;)
DeleteFinished this pedal today. This is a hidden gem. Not quite a trem - not quite a vibe. We used to have a vibes player named Jon Metzger play at a restaurant I worked at in the late 80s. This gives your guitar that vibraphone sound. Not that horrible seasick warble-y sound ( yes, sometimes I like that too ) - kinda a tremolo and uni-vibe combo.
ReplyDeleteMadbean has a couple of resistor values to change at FSB for a little more speed control but this layout is fine as is ( I'll probably build another with the Madbean changes to see if I can get a slightly slower vibe too tho' ). I will be building this as Christmas presents for close friends who don't know what they're missing. I can't stop playing with this on.....
I just finished this one, big volume drop engaged, but there is a very subtle vibe there. I used 2n2222 tranny's though, would that cause my volume drop? I have a few more LED's and LDR's to mess around with to get a proper vibe from it.
ReplyDeleteBill
DeleteNo volume drop at all on mine. I just looked up the data sheets on the MPSA18 vs the 2N2222. the hfe on the MPSA18 shows up as between 500 and 1500 ( mine have usually measured around the 900-1000 mark ). The gain of the 2N2222 is only about 100 to 300 hfe so I would imagine that might be a factor in the volume drop. Did you socket the trannies so you can swap?
I will say that I used a 10K to 1M LDR so my vibe is just a tiny bit less intense than the demos that I have heard - not a big deal since I still find myself turning down the depth a little as is. I have a 20M LDR that I will swap out to see how big a difference it makes though, just out of curiosity.
Also, I think someone already mentioned earlier - make sure that the LED is pointed directly at the LDR and either in shrinkwrap or black electrician's tape ( I used tape because I was out of the proper size of shrinkwrap and it worked fine - just not as pretty...).
I love this pedal...
Aye I socketed the traannies, and the LDR/LED. Everything's ready for tweaking, MPSA18's in the post.
DeleteI'm a bit confused about this, it only seems to work right for a second after I pull the power. Grounding problem? it's in a plastic enclosure with no switch, I still haven't got the mpsa18's I suppose that could be it?
DeleteIt's fixed! Working perfectly now, when I went to socket the new trannies it turned out I had one of the old ones in the wrong way round. Really nice effect, I just need a decent enclosure and a switch to go with it now. Thanks
ReplyDeleteI've rebuilt this two times, but, I've got a pure clean sound when I play it...
DeleteI've checked the orientation of the MPSA18, and everything seems ok, can someone help me with a picture of its build?
Bye ! and thanks in advance !
hopefully you can see these. https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-ash3/942207_320652808062254_1012549100_n.jpg
Deletehttps://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-ash4/302948_320652538062281_401525405_n.jpg
Satcher
DeleteIf you don't have the led/ldr enclosed in something like shrinkwrap or electrician's tape ( so no outside light can get to it, it won't work ( unless you're testing in a dark room or you have it in the enclosure so no light can reach the pair ). Is outsode light getting to it when testing?
Glad you got yours sorted out, Bill. Do you know what value your LDR was?
Pretty sure I used this one http://www.musikding.de/Passive-parts/Resistors/Photo-Cells/Photo-cells-35k-210kOhm::3088.html 1M Dark resistance
DeleteDoes the anode of the LED connect to depth 1+2?
ReplyDeleteIt's not marked in the picture.
That's correct. I had checked against another layout and confirmed that before I wired mine up.
DeleteHi, I've finally my vibe working, but LFO is really noisy, anyone has the same problem? Any solution?
ReplyDeleteI've a 'ploc' when I switch pickup.
Thanks in advance.
I use those http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=120343782559
Deleteand a classic 5mm led
I'm having problems finding these LDR's, can anyone help?
ReplyDeletewould it be possible to split the signal so this becomes a stereo tingy? really interested in this, thank you for all the resources, very helpful
ReplyDeleteIt wouldn't be true stereo unless you built 2 of them, put them in the same case, and sent each one to a separate output.
DeleteI built this and could not get the affect working. I tried a few VTL5Cx's. The circuit and build all looked Ok. I Finally found the culprit, a single metal strand quite invisible from the Input Wire connection was touching that side Link. As soon as I removed this and tried another VTL5C1 this time it worked fine. Mystery solved. Such is Pedal Building. LoL.
ReplyDeletehi
ReplyDeleteI just built this pedal and it sound very cool but is there a way to bring the speed down
tnx
This one's a sleeper. Built this with a optoisolator, the results are exactly like in the youtube demos. Very unique sound, gonna try and fit this into my band's sound. Getting a little tired of fuzz/OD stuff so I guess I'll try out some more modulations next. Already did a Phase 90 and it turned out well.
ReplyDeletewhich optoisolator did you use?
DeleteVTL5C1. Sounds absolutely killer! It got a slot on my pedalboard and I use it in every rehearsal now :)
DeleteWow Myrkky, that's an expensive part! I'm going to see if I can get the equiv LED LDR combo figured out from the datasheet.
Deletejust an fyi for you guys- when you put pedals into enclosures you are not getting complete darkness if you have an LED installed. the small amount of light that comes off the bottom of LED's can easily light up a dark enclosure pretty well. it affected my clarinot after I boxed it!
ReplyDeleteThats interesting and important to know, I've often wondered if there is enough light contamination to affect ldr based circuits. Was the difference quite noticeable when you addressed the problem?
DeleteThanks
Dave
If you put the LED and LDR, facing each other, into a short length of shrinkwrap, they are pretty well isolated from any external light. It has worked in all of my pedals.
DeleteI built this and it sounds great with a number of different LEDs. Very cool effect- thanks for the layout. However, I feel like I'm not getting it as slow as it is on video demoes ive heard. Everything is working properly- it just doesnt get very slow. Got any suggestions for getting my slowest speed slower?
ReplyDeleteI too would be interested to know which resistor or cap change would possibly slow the speed a bit more when the speed pot is at zero rotation. Thanks in advance.
ReplyDeletemy light just stays on is it supposed to blink
ReplyDeletedamn now the lights blinking and ive got the led and ldr covered in electric tape still nothing
ReplyDeleteWell, the speed thing has me concerned. I haven't built this yet, but in concern for the speed issue, I went ahead and ordered the VTL5C1. Oh well, the pain of poor craftsmanship far outlasts the joy of low price....or something like that...
ReplyDeleteThat said, if you are looking to get it slower, the 2k2 resistor and the 1u capacitor that go from speed3 lug to the LED look promising for sockets and adjustments....
This has been on my board since the day I built it and I'm keeping it! One thing bothers me though, it boosts treble frequencies a bit. This is annoying when I'm purposely using dark sound for certain passages. Any ideas how to counter that without interfering with the circuit too much?
ReplyDeleteglad you like yours. I gotta ask are you able to get a decently slow rate? My speed knob does not change the speed from like halfway up to all the way down. It really just goes from moderate fast- to pretty fast. I also dont get much use out of the depth knob, but i think that may just be my LDR. What did you use for your LDR or did you use a vactrol? if so, which one?
Deleteworks perfectly and i absolutely love it, wanted to share my findings about used optokopplers: VTL5C1 works ok, tried a VTL5C2 and it sounded noticeable better, deeper, more wobbly, mor like Tim Lerchs demos, (VTL5C4 did not work, no depht), what i finally installed is a white 5 mm led (blue, green, red no good) and a LDR 70k-200kohm (Musikding Germany order # foto70-200), put this in some heat shrink tube - i think that sounded even better than the VTL5C2
ReplyDeleteGlad you like it and thanks for sharing the info
Deleteare you able to get it to have a decently slow rate?
DeleteI used a VTL5C1 and it works fine on slower settings. It also gets VERY wobbly on full depth.
DeleteJust got couple of these together with VTL5C2s, and the speed range works - although to me it is a bit too fast even on the lowest setting. I'm happy with these builds for now, but if i'm going for another one at some point, i might try to halve the speed with 2µ2 caps instead of 1µ. Just a hint for those who feel the slowest speed is too fast...
DeleteActually these are parts of my "Aliupseeri Päärynä" experimentations.... :)
+m
I though about those caps and what would happen to the speed if I altered them but didn't bother. Would that alter the whole sweep as in also lower the maximum speed available? I actually love this on full speed. Pair it with a subtle full speed phaser and you've got a very believable leslie sound!
DeleteThat should cut the whole range to half... I'm thinking about replacing the whole LFO with something a bit more versatile. The main circuit is pretty ingenious in its simplicity and one should be able to use almost anything as an LFO for driving the LED...
Delete+m
That's true. The differences are just huge. VTL5C1 was smoother but also a little too subtle compared to C2. Now the C2 is deeper and wobblier but also a little bit choppier and it doesn't get as slow. Well. I use it as a pretty mild effect with a fairly fast speed so I'm perfectly happy with the C2. Endless room for experimentations with the LFO+LED combo so I won't even start 'cause I know it won't end. Ever. :D
DeleteAlright, I can confirm that VTL5C2 sounds a lot better than VTL5C1. Much deeper, smooth and pronounced effect. More vibe-like, definitely. I also put a 220k trimmer in series between the switch and input to lower the output a little bit. It boosted my amp and made the trebles shrill. Now it's set somewhere around 100k and sounds magnificent. Also doesn't change the volume level. Couldn't be any happier with this :)
ReplyDeleteI ve built this one and sounds really good, i d like to know if this could be modified to turn into tremolo with a switch, i read somewhere that magnavibe has lots in common with a ROG project, and that ROG , was looking similar to the EA tremolo, so if they two could be combined, this would be awesome. From vibe to trem through a footswitch. Thanks for the layouts!)
ReplyDeleteSergio this is the trem/vibe... http://www.freestompboxes.org/download/file.php?id=16726&mode=view
DeleteHere the topic: http://www.freestompboxes.org/viewtopic.php?f=28&t=16239&p=182154&hilit=lunevibe#p182154
Thanks a lot, Giudis, seems what I was looking for!-) I'll give it a try and I'll leave my opinion here when it'll be done. Thank you!
ReplyDelete:D
DeleteI was sure I had left a reply, but I can't find it! Well, my experience with the magnavibe / tremolo from giudis posted link at fsb is that the trem is not as good as the vibe, vibe keeps sounding so good, although. So I would recomend different builds for va tremolo, what a pity, since changing from a clean vibe to fuzz trem with the same tempo would be so great!
ReplyDeleteThe LFO is exactly the same as the one used in the EA Tremolo, so it may be something that you could cobble together the two to share the same LFO and you could always add switching to select between vibe and tremolo mode so the tempos are in sync.
DeleteThis comment has been removed by the author.
ReplyDeleteFriends, I have a volume drop...is it possible increase it? and regulate it with a pot? Have I to change anything?
ReplyDeleteSame thing here with the volume drop...its pretty significant but signal is passing through in both bypass and effect mode...
ReplyDeleteno volume drop at all in mine. not sure what it could be.
ReplyDeleteOk, I¨'ll eat my words now. I'm back to VTL5C1. It's better, especially with a few mods. It makes sense too. It's 1M vs 50M dark resistance. Change the 1k8 resistor for something around 800 ohms (any less will make the speed faster) and change one of the 1u caps for a 2u2 for a little slower speed. Now this things sounds just amazing. I slowed it down even more but actually, it sounded very bad. It started to go very choppy like a tremolo. It would need a modulation of some kind to work with just a slow speed. The 2k2 resistor connected to the speed pot can also be subbed to adjust the speed. The problem is that the more you cut the speed, the more you lose that lovely wobbly vibe sound and start to sound like a bad tremolo.
ReplyDeleteI've just built this and tried various options. I ended up with the C2 which I found to be more pronounced (although I think slightly faster). I'm waiting for some LDRs so I can try them out to see if I can find a better option.
DeleteI agree with you regarding the 1k8 resistor - I settled at an 820R value.
I also changed the 2k2 to a 1k5 but ended up retaining the 27k resistor in parallel with the speed pot as it lost the slower speeds.
I the next build I am looking at the three 1uF caps to increase to possibly 2u2 to help slow the vibe (I'd already soldered the 1u caps in place so missed the opportunity with this build).
Despite all this, it could still do with a little more depth, especially at the slower speeds (unless I've done something wrong with this build)
But it is still a nice sounding pedal - I just need to box it now once the paint has hardened.
I soldered my electrolytics off and put mounts in there. One 2u2 replacement is definitely better than stock, two subs starts to be a little meh and three 2u2 caps just sounds bad. I don't think the design handles such low speeds very well. Unless you like a choppy in your face tremolo-style vibrato. Many people like that too so everything's worth a shot!
DeleteThanks Myrkky. I'd read a little bit about LFOs and most diagrams I saw showed the 3 caps with the same value. I suppose I shouldn't assume and have a test like you. Which one was the best to sub?
DeleteAnother though crossed my mind last night - I didn't play with the transistors. The gains in my build were about 620hfe, maybe I'll try a higher gain in the 'effect' position - not sure but might increase the gain a little. I also tested the LDR/LED before playing with the resistors - might have another bash and try a higher value for the 27k while I'm at it again
I've done some more testing since getting a few more LDRs
DeleteI kept the changes previously made to the 1k8 - reduced to 820R, 2k2 - reduced to 1k5, retained the 27k parallel with the pot. I also changed the transistor in the audio path to a slightly higher gain (but I didn't seem to notice a difference to the depth) (hfe = 770)
I made a little test rig out of a plastic pill box (painted the inside black) covered it in black tape, and used the bottoms from LED clips as spacers and some blue-tac.
I tested the Vactrols, Tayda LDR, GL5506, GL5516, GL5528, GL5537-1, GL5537-2, GL5539 and GL5549
I used LEDs - red, yellow & green diffused - red, yellow, green, blue, white clear
I tried them at 10mm, 6mm and 1mm
The combination I found to give me the best sound (particularly at slow vibe which is what I am after) was the GL5528 with red 5mm diffuse LED at 1mm from the LDR. :D
Now to box this thing before I wreck the board anymore and I can get on with another build. Maybe next time I'll change the capacitor - just getting a bit impatient now
got mine working after I swapped the LED! first red 3mm led i tried did nothing, second one was very subtle, and then tried a white 3mm led and it works great. Still a pretty subtle effect even maxed out but sounds great!
ReplyDeleteIs the input linked to rows 3&5? Or is that just a jumper from 3-5 and the input is by itself on 4?
ReplyDelete-Kris
No the input isn't linked. I just didn't want to add an extra column for 1 x 5mm link! :o)
DeleteThanks, Mark! You're the best!
DeleteAnyway to modify the layout so that the dry signal can be mixed and it can double as a chorus and vibrato?
ReplyDeleteYou can use the split N blend. I wish I head read that comment before I built this tonight! Anyway, it sounds great. Most of the settings are unusable because they are so fast and deep, but the subtle settings are very nice! But yeah, I might just have to add a split N blend to this one. My Boss Bass Chorus has a blend knob and it is worth its weight in gold.
DeleteBuilt this and boxed at last. However when I connected the power I got a high pitched (low level) oscillation (squeal) which wasn't there before. Checked everything, moved some wiring, but no change.
ReplyDeleteIn case anyone else gets this, I solved it by placing a 100R resistor in series between the DC+ on the power socket and the power lead to the board. Its now quiet as a mouse and the effect is loooovely and swishy.
I'm having the same issue Dudave had(no guitar signal is passing but I can hear the sweeps from the LDR) I have checked all I can think with the multimeter and nothing. I am curious if there is an obvious issue others had and corrected. Dudave said his now works but without what the prob was. This is driving me nuts.
ReplyDeleteMine worked fine first try. I've used a combination of LDR 5-20K (light) 20M (dark) (type9203) and a 5mm Red led (bright version).. really enjoying this one.. and also the first pedal I tried on the bench with the lights out ;)
ReplyDeleteI ve built mine but i have a really big volume drop. Any ideas of what could that be?
ReplyDeleteI tried replacing the ldr/led for a vtl5c3 I have, but it did the same thing. Loosing a lot of the high end as well. Seems to be the ldr, cause with the ldr leads touching each other i get normal sound, with no effect. Everything else is working, the speed and depht are all fine.
DeleteRebuilt from scratch and she fired right up.
ReplyDeleteLed ldr shootout tips and pics of my build
ReplyDeletehttp://masutopedals.wordpress.com/2014/10/19/magnavibe/
I just bought one of these pedals already built. It sounds pretty good. There is on optoisolator in the pedal instead of the LDR. I ordered the LDR & LED's you guys recommended along with a vtl5c2 to see what I am missing, if anything.
ReplyDeleteAnyway, I like the pedal but it has a lot of hiss when it is engaged. Do you guys have any idea what could be causing this and how I might be able to control it?
Finished this pedal today sounds great! but how can i wire up a simple slow/fast switch like on the bigger version of the magnavibe? thanks
ReplyDeleteLo arme hace un par de meses y anda muy bien tal cual esta, use ldr y led rojo difuso.. algo a tener en cuenta es el transistor, con 2n5088 funciona exelente, con mpsa18 no me gusto.
ReplyDeleteI've just built this today and cannot get a sound from it at all. When I turn the speed and depth pots sometimes the LED pulses and other times it doesn't. Then when I engage the effect I get an oscillating noise through my amp, but no guitar signal. I've tried 3 different LEDs - 2 5mm and 1 3mm all different colours and no success. Has anyone else had this problem?
ReplyDeleteSpent an hour on this again today and I think I've figured it out! I've changed the LED (for the 6th time!) for a clear lens 5mm red, changed the cap that is linked to the LED for a 2.2uf and changed the 1k8 for a 680r and the 2k2 for a 1k8. The transistors I settled on were a 2n2369 in the first position from the left and an MPSA13 in the second position. I'm really liking the lush vibe tone from this now!
DeleteHey, quick question here. Does the input wire connects with the jumper? I know it is quite silly but I'm going crazy here. Thanks.
ReplyDeleteNo the input wire connects the the row in between. Just push the link to the right slightly
DeleteI just finished building this and the effect is very very subtle. I can hear the speed change as I turn the knob but the actual 'vibe' effect is extremely mild. I'm trying to diagnose what is wrong with my build. I have tried both a VTL5C2 and VTL5C1.
ReplyDelete-Do both of the ground points in the diagram need to be connected to ground? Or just one of them?
-Does the polarity of the optocoupler matter? There is no polarity shown in the diagram so I assume no?
Both ground points on the board need to be connected to ground.
ReplyDeleteThe polarity of the LDR does not matter but the polarity of the LED portion of the optocoupler does matter
If the effect is still to subtle after you're sure that the board is grounded correctly and the optocoupler is installed correctly, you may want to try out some different LED/LDR combinations to get the best sound
I used a waterclear blue LED and an LDR with a very wide resistance sweep. Can't remember the LDR model number
This comment has been removed by the author.
DeleteBuilt this one a while back,and it's a lovely effect. That said, I think it should be pointed out that it's not a true vibrato ie. it is not modulating the pitch
ReplyDeleteIvIark?
ReplyDeleteWould it be possible to add an external LED that pulsates with the optocoupler?
You could add a second LED in series with the internal LDR LED. At the moment you have one side of the LED connecting to Depth 1 & 2. You'd need to take that wire to the external LED you want to use, and then take the other side of that LED to Depth 1 & 2. Make sure you keep the anodes and cathodes in the correct orientation.
DeleteI tried doing this, but it seems that the led brifly pulses but then stops blinking, do you have any idea why this might be?
Deletesecond question,
ReplyDeleteany verified alternatives for the MPSA18, they're currently out of stock.
BC550C's are available and quite cheap, but I wondered if they will work well before i order them
I useds 2N5088s just fine
Deletehi,
ReplyDeletecan someone post the schematic?
http://revolutiondeux.blogspot.com/2012/01/bigfoot-fx-magnavibe.html
DeleteSo this is a weird one... I built this, and it works and sounds great. So thanks for that! But when boxed up, I am getting a tremolo (variation in volume) with the effect off, and it is as controllable as the vibe when the pedal is on. It is actually a nice effect, and was obviously because of the way I wired the ground. So I wired the box so that all of the circuit grounds go through the switch, so when the pedal is off, they aren't connected. Well this worked, except now I have a huge pop on the footswitch, I think because I am turning on and off the LED running the effect. I tried a 2.2m resistor from input to ground, but it didn't make a difference. How are you all wiring up this pedal to not have these issues?
ReplyDeleteAlso, I think I figured out a way to keep the tremolo effect on a switch. :)
ReplyDeleteI'm super happy with the build, all works as it should. I'm keen to hear where people ended up with slowing the speed? Was it just changing one of the 1uF to a 2u2? Or was it changing all three of them to a 2u2? Cheers
ReplyDeleteI built but my speed knob has no effect. I am using a 5mm green diffused LED but it doesn't flash/blink when i turn the speed knob. Any ideas?
ReplyDeleteThanks in advance
Soooo...still no solution on volume drop?
ReplyDeleteHello,
ReplyDeletethe circuit works very well, nice and soft warm vibrations! I use it with my analog synthesizers. I bought a rotary switch (4 poles, 3 ways) and so I can switch between normal, slow and fast. For quick use, use 470n instead of 1uf (I changed two from the 1uf). In addition, I set a B10K potentiometer between 100N and the LDR to achieve a tremolo effect, instructions are available on the Internet.
Great job, thanks for posting!
Magnavibe Mods
ReplyDelete1. More or less modulation effect.
Change 100nf capacitor value for more or less modulation. 220f gives more modulation, 10f give very mild modulation.
2. Faster of slower effect.
Change the 1uf electrolytic capacitor for a larger value to slow the speed of the effect, or a smaller value for more speed. You only have to change the 1uf that is in direct contact with the LED.
You can add a switch in place of the 1 uf to switch between different values for a slow/fast switch.
For example, 1uf for fast and 4uf for slower. You can use different values, or just switch multiple 1uf caps in parallel. example: 1uf + 1uf in parallel equals 2uf. 1uf + 2uf in parallel equals 3uf. etc.
3. Turn vibrato into tremolo effect.
Change the 100n capacitor for a resistor to turn the vibrato effect into a tremolo effect.
between 1K and 20k ohms work, 1K being very very exaggerated effect (more like a heavy volume swell) and 20K give very very mild tremolo effect. I find 10K ohm to be a perfect.
Change the resistor for a 10k or 20k linear pot. This allows you to change between very heavy and very mild tremolo effect. Any higher than 20K and the effect goes from heavy tremolo to dry guitar signal. 20K is hardly any vibrato anyway. The pow will set the tremolo’s intensity.
The depth and speed knobs are shared between tremolo and vibrato.
Depth is more a “mix” knob.
4. Add switch for vibrato AND tremolo effect in 1 box.
You can take out the 100n capacitor, and add wires in place. Connect these wires as the in and output of a on/on switch. Add 100n (or value of your choice) to one side of the on/on switch, and a resistor of choice to the other side of the switch.
This allows you to switch between vibrato and tremolo
Change the resistor for a 10k or 20k linear pot. This allows you to change between very heavy and very mild tremolo effect.
The speed and depth pots are shared for both effects.
5. Tremolo, vibrato, chorus switch.
Use a on/on/on switch.
Add the 100n cap to 1 position for vibrato.
Add the resistor or tremolo pot to the other position for tremolo.
Add 100n cap AND a 50k resistor in parallel for chorus.
I tried a 50K resistor which works fine. The chorus effect isn’t very strong but its a bit different that just vibrato.
NOTE!!!
The mini switch pop’s when switching between tremolo/vibrato/chorus.
Haven’t been able to resolve this unfortunately.
6. You can add a LED in parallel to the LED that is connected to the LDR, this led acts a speed/depth indicator. I think you could use this led as the fx on/off led.
Hi, built it, it works, but vibrato is very weak, i can hear it a little bit on the max pot value, tried 1m, 5m ldr, changed led - not much difference, transistors are mpsa18, can anyone know what do with this?
ReplyDeleteWhat is the orientation of the LED?
ReplyDeleteHey I know this is an old one but wondering if anything can help! Having an issue that's got me very confused. I am getting clean signal in bypass as well as when the effect is switched on, I have the LED showing when on but no effect. The LED/LDR combo responds to the depth knob, but it stays consistently lit regardless of the Speed setting.
ReplyDeleteI'm guessing the issue is around the Speed potentiometer but I'm unsure where to start. I have used audio probes in the past but if the signal is passing through fine I don't know if that would even help. Any ideas on where to start with troubleshooting?