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As discussed before in some other threads, I've been trying to get some tremolo to blend in with the vibrato. I used to have a real Leslie rotary cab, modded for guitar amp of choice, of course. Anyway, it was cool and the sound cannot ever be reproduced in a pedal but I'm getting closer, With much help from, and a big thanks to, kipper4 and duckarse!  :)

I put a 10k pot after the cap coming off Q1c, right before the LDR/220nF. I think a trim pot will do for this but for the purpose of my demo vid I'm just using a 10k resistor to show max tremolo blending. A 100k pot could probably even be used for getting almost pure tremolo but I don't know for sure.

The more trem I add, the more output volume I lose so I added an LPB-1 booster stage at the end so I can turn the volume up as I switch back and forth between straight Magnavibe and tremolo mod.


EDIT: add schematic yo. Using 1 LDR app. 1M dark with 1 brite white LED facing app. 1/4" away. Second brite white LED is for visual and extra volts drop across the first to increase depth.
(http://i65.tinypic.com/2hhorqb.png)
EDIT EDIT: parts values changed to reflect accurate BB layout and speed/depth pots adjusted/labeled for correct wiring

Just following to see how it unfolds. Sounds like you could push the boost stage after this to get a nice grit, too. Nice!

nothing useful to add, but i just built one of these to. I didnt have 25k lin pots, tried 50k and 100k with all kinds of resistors across lugs 1 and 3 and some going to 1 and 2 and 2 and 3. Had massive volume drop no matter what i did. just had the photocell pack from radioshack but data sheet looks like theyd work in circuit. The vibe was really nice but i leterally had to turn 10 watt solid state amp to 10 to get what id normally get on 1 or 2. Needed 50k pots for a delay so i fmoved on.

Rob, you know if you follow long enough you will eventually see a completed pedal and a vid of me making a gawdawful racket with my hamfisted attempt to play guitar!
I have something very special in mind for this build so keep watching  :)

Fndr8875, I'm not sure why you had volume troubles, that's too bad. I used B50k pots with 51K resistors across both, kept one on the speed knob but eventually changed the depth to a B10k.
If I had to guess, I would think LED/LDR combo. I've spent a little bit of time with these, built 2 already and now this thing that I'm working on.
If you ever want to try again and you feel like you're having trouble with the vactrol, send me a PM and I can give you some pointers, see if we can dial it in. Or ask around here, there are some guys that really know how to do it, those are the guys that got me through my troubles.
Good luck!

I made some changes to the schematic. The main thing I am curious about is a good way to lower the input to the final stage. Rob, some OD might be cool but I kinda want to avoid it on this one, I might even try an internal trimmer for the output volume. That way I can set the tremolo/vibrato trimmer and then adjust the output volume trimmer, close it up and play.
So for now, as seen almost dead center, a 10k (R20) but is there another trick? Like changing R17 or something?

I've bread boarded it yet again with a few value changes. I'm using 2k2 for R10
Included are the Duck Arse trem mod (inc BAC) and the Lyman trem mod.
With my observations.

(http://i.imgur.com/rfUgaGN.png)


Errata.
I forgot the 10k input resistor on the LPB.

err. anyone interested in my take (add more parts!) can see a completed diagram here:
http://i.imgur.com/gkfvLAL.png

and anyone interested in a matching 20x10 game of tetris perf layout suited to 1/8W resistors flat, or all quarters standing, can look here:
http://i.imgur.com/GZRwo74.png

@kipper - did you get the BarseC mod to work?

@Ben - are you aiming for either vibe or trem, or both at once to some degree? is your C5 really only 10nF? I always find your 'ham-fisting' a good listen, you cover so much ground. (I haven't listened to the current demo yet.)

Thanks Rich, looks like I have some more experimenting to do!
I wanna figure out that choppy trem thing, everything I try either gets that ticking or just doesn't work at all.
I did try a 100K trimmer for my tree blend and it got much more intense without the ticking but not exactly choppy.

Quote from: duck_arse on May 17, 2016, 01:21:21 PM

@Ben - are you aiming for either vibe or trem, or both at once to some degree? is your C5 really only 10nF?

Thanks duck! Yes, both at once, and just the right amount of each, nothing too extreme.
Also yes, 10nF. I tried the LPB 100n and thought I was losing a little too much high end, now I have 2x 10nF's in series right there plus that 10k to lower the LPB input. Do you think there is too much going on right there and can somehow be simplified?

Note also how I have used a 1k2 on my speed pot, it goes super-fast now without dying out. I couldn't do that before I added the second LED because superfast=LED always on. Now superfast=LED blinking superfast  ;D

just for fun and S&G and curiosity, try putting a cap 47nF~220nF across R8 to ground, tell me wot it does ....... if anyting.

I put my gain at the front and used high Z buffer at the back for some sort of consistency, so I dunno how the loading at the mix point effects anything. and I switch the ldr to a proper shunt in my dia, if you can follow that bit. the trouble is, every throw of that mode switch gives a pop that can't be cured.

Always fashionably late to the party......
The Duck Arse mod referred to in my earlier diagram is with reference to this.

Quote from: duck_arse on May 15, 2016, 11:29:50 AM
you blokes - yer mixing the DC from the collector wit der DC from the emitter. put a whacking big cap (to pass all freqs) in between the collector and the so-called L cap, then hang your Lyman resistor across the L cap, and report back.

[edit :] oh, and kipper - don't forget to "lard up" for your swim, to keep warm. I think the pro's favour goose fat.

and I saw pipporan, huddling under his umbrella, at the giro.

From another magna thread.
No offense Stephen. I was not putting words in your mouth.
The trem is choppy with this mod. As it was in my own earlier trem mod from way back.
Also IIRC the speed varies slightly turning this pot......

The Lyman trem/rotary mod was much more subtle. More desirable than anything I've managed to hack up.
I changed some PSO values to get the speed ranges I felt suited my needs. YMMV.

I haven't used the LPB mod yet, I just thought it needed including in the drawing.

Ps no goose grease needed. I have a wet suit. Only trouble is the fishermen keep shouting "whale ahoy"
It was a giggle of a day.
So many things to do especially now the concertina splitter is back on the BB.
I can get round to doing the cro experiment Stephen, sorry for the sattelite delay.

Carry on concertinaing guys. Smoke me one I'll be back for brecky.

More Vibe messing. Just a few value changes and notes

(http://i.imgur.com/sfJZtnD.png)

Have you thought about or experimented with a dual gang pot for the trem/rotary control and R15, biasing the stage hotter as you turn the effect up? You would lose some signal strength from the emitter of Q1, but maybe worth a try?

Or better yet, throw another LDR near the LED and wire it into part of a voltage divider with a fixed resistor and a pot to adjust the depth.

Sounds like some cool ideas Dmichel123, thanks... and welcome to the most awesomest forum on the infrawebs!

Like this:
(http://www.strymon.net/wp-content/uploads/2012/04/trem_fig4-1.png)

Let me know if I should just shut up... I'm just sharing ideas I had when developing my vibe/trem pedal. What you're doing is mixing between tremolo and vibe, with both effects being less intense as they're mixed together. If you create the tremolo in another way, you will then be able to mix trem with full strength vibe.

on the contrary, please share more! this looks like a good idea. I will try it out before I take it off the breadboard, thanks!

hmmm. DMichel, also hello. you have as many likes as posts, a rare start indeed.

following from your trem idea, and what I put on a switch in my above circuit, and Ben's "Lyman pot"/kipper's "trem/rotary" control. that pot will work as the series resistance for a shunt trem, if you hang the tremming ldr between the rotary pot and the lyman cap to ground. it just might work.

and kipper - any bike races near your house ?

Yes, it does work, I tried it last night and I like it, very choppy trem at max turn of the pot (ugh, I hate more than 3 knobs on any pedal!)
I was hoping DMichel's trem would eliminate the need for the LPB but alas, it seems perhaps the curse of all tremolo circuits is a volume drop.
Oh well, I might have to incorporate this new trem idea on my next BB adventure into the magna vibe, for now I think I will stick with the plan and box it up as it is.

The bikers are hitting Folsom about 20 min. away from me before they go downtown Sac.
Russ posted this and I had to laugh, it reminded me that I was trying to navigate a piano moving truck through S.F. during the first ever "critical mass" gathering
http://www.diystompboxes.com/smfforum/index.php?topic=111745.msg1058757#msg1058757

Heres some cycle p.o.r.n for you D.A.
Lincoln Grand Prix no less.

http://www.lincolngrandprix.co.uk/site/


Plenty of prix on cycles the day before as you well know my friend.:)
Rant over.......

Hmmm... I never tried doing opto trem on my design. What values are you using for the pot and LDR? I would think that if you simply replaced the 2M2 resistor at the input with a 1M pot and used a 5M+ (dark) LDR, you would still have full volume on the up swing of the trem modulation.

Quote from: duck_arse on May 19, 2016, 10:59:32 AM
.....
following from your trem idea, and what I put on a switch in my above circuit, and Ben's "Lyman pot"/kipper's "trem/rotary" control. that pot will work as the series resistance for a shunt trem, if you hang the tremming ldr between the rotary pot and the lyman cap to ground. it just might work.
....

I am a goose. coming from the collector, the ldr to ground will mess with the DC, and we can't have that. so it would need another cap between the DC and the ldr.

as for what value, it depends on how deep you want, how bright you can go, how low your ldr swoops. with a GL5539 shunting a series 22k ~ 47k, and a superbright led, you will get A LOT of pinch. I haven't yet gotten to trying either of the two depth methods I can think of, one of which is the lyman pot mentioned.

I've been trying to convert this circuit to use valves - that's a different story tho - and it isn't working yet, so I had to put the transistor version together again to hear what it was supposed to sound like, and try summa the collected mods.

messing with the oscillator - ben, if you want a longer knob, you can add a fourth phase stage. I added a fourth 680nF to the string, with one fixed leg 56k and one 68k, and a 250k pot w/ 2k7 stopper, and have full pot range. it works, but I'm not using the standard dimmer/depth pot, mine runs parallel with the collector resistor, which also afects the stoppings.

and, perhaps the easiest mod-to-trem with the base circuit, is to simply open the connection to the cap at the collector. (I can't remember, is that one of kipper's?) it produces a VERY chopping trem, and about nothing else, I heard v. little depth change.

Thanks guys, I've been busy with boxing it up.
Duck- I'm very interested in the 4th stage addition but it will have to wait until I start over on one of these later.
My kids are bouncing off the walls so I don't have much spare time right now but I made a short vid. As promised, something special for this one. Depth, volume, and mix controls are on 3 trim pots:

Good work Ben the rotary mod works well.
If you set the trim pot for the rotary static you could just meter the trimmer setting and replace it with a set resistor of nearest value for a cheaper mod.
Good work man.

Yup, sounds cool! Has a nice throbby vibe.

We need a thumbs up smiley.

Thanks guys. Ya kipper, I was thinking for my purpose about 5k-10k sounds about right for the trem mix trimmer, so maybe I'll just make a decision and put a resistor in next time. I dialed the depth trimmer down a little because I upped the speed with that 1.2k resistor, and with that at top speed the depth needed a little adjusting. I like where it's at now, two speeds and both sound pretty good wherever I set them. Less knobs equals more music!

so the second footswitch is just selecting speed pot a or speed pot b?

I'm mighty impressed by that double-humper resistor, the lyman rotator, the kipper collector, what the hell is it called? it does mean I have to rethink my switches tho.

Quote from: duck_arse on May 23, 2016, 11:33:44 AM
so the second footswitch is just selecting speed pot a or speed pot b?

I'm mighty impressed by that double-humper resistor, the lyman rotator, the kipper collector, what the hell is it called? it does mean I have to rethink my switches tho.

Yup. I just ran a wire from the board to the DPDT middle lug, outer lugs each go to the CW lugs of the speed pots (all CCW and wipers to ground)
The blinking LED's share a connection to the vactrol and a connection to the DPDT. I had to draw a pic to figure it out but it looked like a toddler's depiction of a bird's nest. I tried to redraw it yesterday and this was the best I could do.
(http://a63.tinypic.com/2rgnuag.jpg)

What value pots are you using for the two speed pots please Ben?
Thanks.
Kipper collector. Ahh no.
It was all Mr Lymans work. I just trialed it on the breadboard for him to see what value I liked best.
Great work Ben, you should be proud.

"Less knobs equals more music!" Not what you want to hear is it D.A.?

Kipper, speed pots are both B50K, I was trying to go as slow as I could without killing it and that's what I came up with. Hopefully one of you can do better, I like the top speed (w/1k2) but it would be nice if it could go real slow too.
Duck, is that what you meant by "longer knob"? ability to go slower and faster? Because I thought maybe you meant something different...  :icon_lol:

Thanks pal.

more knobs! add some switched caps!! put more parts!

ahem. yes, ben, a longer and wider knobbage range is exactly wot i ment. I've got the new! improved! 4 phase version running from ~ 9Hz to ~2.5Hz, using 250k and 2k7. "C" would be better, but I'm "A" taper backwards at the moment.

it strikes me that you could put a low value pot in for a wider band-spread fast side, and a larger stop R and bigger value pot for a slow range that doesn't overlap too much. it would mean a lot of fiddle. let me know if it sounds like a thing, I'll maybe work some numbers.

Quote from: duck_arse on May 24, 2016, 11:23:45 AM
...a low value pot in for a wider band-spread fast side, and a larger stop R and bigger value pot for a slow range that doesn't overlap too much...

Sounds like a great idea Duck, like I said the fast side goes plenty fast but it would be nice to get some really slow action too.

In a perfect world, my pedal board would have nothing but footswitches and all the parameters would be perfectly preset so I never have to adjust anything  :P

How's the 4-stage sounding? I really want to try that out but can't get back to the magna vibe yet as I just BB'd the JFET Vulcan again

the 4th stage is just an oscillator mod, doesn't affect the sound. there is plenty other things create madness in there. try putting a 10nF~22nF cap between the emitter and the ldr. gives you the hump.

surely, both you and kipper have a breadbord dedicated solely to the magnavibe, non? a constantly-built test bed you can just reach out for?

my BB station is kinda limited and it's all sticky-taped down together on one big platform so I always have to rip everything out when I start a new project  :(
I just might rip the current JFET Vulcan off and go back to the Magnavibe, this extra stage has intrigued me... and now your "hump cap"... hmm...
I have read your description of it several times but is there a chance you can post a schematic of that addition? even just a pencil sketch or something of the sort

For slower LFO speed, I used a dual-gang 20k pot to alter two legs of it at the same time. I haven't measured the frequency at the slowest speed, but I would guess it's down below 2Hz.

I am building these pedals commercially, so I hesitate to share all my "tricks". I'm very new to pedal building, but have worked with tube circuits for 15+ years.

for lyman eyes only:

http://i.imgur.com/7QVByPp.png

this is where I am at currently, a buildable version. shows the "new" version of the pso, w/ 4 phase stages. please note the different led connection. I run the osc full tilt always, and just vary the current available to the flasher leds. the rate led can also be seperated, to blink full brites instaed of vactrol following.

Duck, I took a peak at that schematic...  :icon_eek:

Since I peaked at that, I will share another trick I used on mine. Coincidentally, I have a 2N7000 at the same stage of my circuit. It is biased for unity gain and I have the LFO modulating the bias in trem mode. Like an EA trem.

I tried the 50k speed pot with the 1k5 resistor mod and without. Too slow for my liking. It practically stalled the pso. I'm using white heatshrink on my permanant breadboarded version of the mangledVibe.
I still prefer my 10k speed pot. Sorry Ben.

I tried the 10nf Humpty Dumpty cap. I couldnt hear Jack difference. I tried a 20nf Humpty cap, I could hear it a bit more. The jurys still out on this one because it kinda killed the vibe which was the whole point of the thang. Sorry D.A.

I'll be intrested to see what Ben and DM123 have to say about it......

Don't you just hate it when someone puts loads of full stops after a sentence???????

Thanks for sharing Duck, I see some different cap/res values than what I'm using but I am going to have a go at adding a fourth stage.

Kipper, yes it will kill the LFO but (I think) I got around that by using a 4k7 on the depth pot, and adding the extra blinking LED was key to making it work, plus the 1/4" gap within the vactrol.

I am realizing that it all comes down to what each of us has mashed together for a vactrol and balancing the ebb and flow all around it. I have had such different results from what you guys got that I had to tailor it accordingly. Notice also that my speed resistor is 1k2 not 1k5, the difference was noticeable and when I went to 1k it killed it, that's how touchy it was.
Did yours go slower than what I got in that video on my slow channel? That's as slow as I can go without stalling out. I would like to go slower. But it just dies. If I try. With more than 54.7k.

Seriously... Dual-ganged 20k pot in series with 3.4k for two of the legs gives a perfect range of speeds.

Like I said, I've started selling mine commercially so I'm weary of sharing all my tricks at once. I'm new to the pedal building world, and I realize that there is a different code of ethics within this community than in the amp building community. Is it wrong that I feel like holding on to my schematic until my product has been on the market for six months or so?

Maybe mine isn't quite as slow as I thought... I accidentally ordered momentary switches, latching switches and panel graphics decals should arrive in the next couple days. I'm shipping this thing to Kid Andersen in San Jose for in depth demo videos as soon as it's done. You know him, Ben? My buddy Jon Atkinson is in Hayward and will be getting one too.

sounds great DM123. no, I don't know those guys, I used to live right by the Oakland Coliseum but I've been outta touch with the Bay Area scene for about 5 years.

DMichel123 - PLEASE! don't look .....

(http://i.imgur.com/INDAeKl.png)

as for ben, well, I thought by now you'd realised, there ain't no way to hide those Lyman eyes ......

boom, tish. in the diagram, the right hand version will have resistance in line between the oscillator and ground at all times, the one left will have no resistance while swinging your poles. might be no problem, but there you go.

Quote.... the extra blinking LED was key to making it work, plus the 1/4" gap within the vactrol.

funny. I told someone the other day I thought there was a difference when the led and ldr were spaced, I said about 3mm, tho. I wonder how real this effect is, or just the beam focusing from the led.

DMichel123 again - you don't have to show us anything you don't want us to see. I haven't yet listened to your clip, but I will. and as for
" :icon_eek: ", what, too many parts?

I've yet to try the vactrol spacing thing. Later tonight I guess if i can find the drinking straws.
I posted a page where this was mentioned way back in february.
This is evolving nicely.
It must be me because if a 50k pot stalls the pso a 250k would reverse it, no?

Hows the Humpty Dumpty lumpy cap thing going D.A.?

gorn, kipper, that was days ago! double ldr/double led/inverting sine waves today. I thought I saw some easter eggs, but was sadly mistaken.

the values I've posted/schemmed all need to go together, or close to - one value up or down. you can't sling the big pot into the 3 stage pso (I tested, wouldn't run with more than 100k in the vari leg). the stop resistor for the led brightness also affects the stoppping, reducing the range of the pot both ends. and I'm using the different brightness wiring, so the part values in that string should affect the oscillator dyings less. should.

the resistor values in my schem should work with any string of caps, all the same value. maybe with 1 or 2 off by one value it will work, with flatter output level, but it might stall, too. and you could go a little higher pot value, but I found the slow end change with rotation is so small as to be un-noticable.

Yeppers I saved the drawing but my eyes are stinging. Forgot about the four stage PSO.
Forgive me for saying so but wasn't the triple pole PSO viable because of the 180 degrees out of phase?

So I need to match the Lyman cap and Humpty Dumpty cap values?

I'm always a day behind the Aussies. Some say retarded.
Edit. Does the straw colour have a bearing on the effect?

Hell, I'll just share it... The schematics I have are hard to interpret as one is made in LTSpice for simulating and the other in Eagle for board production, and I can't figure out how to attach them....

My main trick is using two phase shift stages rather than one. Also, as I said before, I also used a 2N7000 for bias-vary trem, with a 2N5457 as the variable impedance element.

Copy Copy breaker

I tried a blue and white striped 4mm straw spacer vactrol // with another led and it does make a small difference ( Note just using my little test amp, I'll do a big boy test tommorow.)
I tried 2x matched 100nf Lyman and Humpty Dumpty caps. I'm not sure if its overkill.

I'll probably keep the straw spacer vactrol//led
and the Lyman rotary pot B10k.

I'll have a crack at a mosfet concertina splitter before I clear the space on the breadboard.


Magnavibe Mission creep central over and out.

Its creeping back in.

I tried the mosfet concertina splitter and it sounds good.
I couldnt get the Lyman rotary pot (10k) mod to work perceptably well with it. I didnt faff about with the value though so it may work with a different value pot.

Try it DA and Ben. You might like it.

you and your bloody straws, kipper. the 3 stage caps provide 60 degrees shift* each, and the 4 stage caps provide 45 degrees each, they have to, because the collector is 180 degrees off the base, so the caps just divvy it up between them. I thimk vat's right.

so, the caps (3 or 4) in the oscillator phase-shift network are the ones for near matching. the lyman is by ear and to suit your ldr, so my circuits show 5n6. the cap that follows needs to pass the audio you want to hear, so big, like 220nF, unless you're some sort of add-more-parts dope, and have a follower following. and the humpty cap is just suck some values and see what they do (but not 100nF, too big).

I've dropped the mosfet as amplifier, it's now phase-splitting, and the follower is now a gain stage. so one transistor less, which might be going back in tomorrow as an extra stage .... or maybe I'll go long tail instead.

DMichel123 - you need to post your images somewhere on the mojo wires, an image hosting site, like imgur (there are others, I won't mention them). they (whoever) will provide you with a URL, which you copy and paste here, in the reply window, between the tags provided by the (http://www.diystompboxes.com/smfforum/Themes/Prince_of_Darkness_201/images/bbc/img.gif) button. [imgur and others also provide a link with the [img] tags already attached.]

then we can set to work ripping off your designs mercilessly see what you've done.


* don't crucify my if it's not 60.

"* don't crucify my if it's not 60."




I tried the extra stage in the pso and yer its ok.
Thanks for correcting me Duck. I believe what you said is true about the 60 degrees thang.
I couldnt get the humpty dumpty small cap to work for me hence my value 100nf.

Theres one good thang about my straws.....

They suck.

I'm more your add-less-parts dope. It figueres a person of means is a cheapskate no?

Not sure if to use a mpf102 fetzer style make up amp?
Thoughts.

(http://i25.photobucket.com/albums/c75/DMichel123/in-trem.png)
(http://i25.photobucket.com/albums/c75/DMichel123/vibe.png)
(http://i25.photobucket.com/albums/c75/DMichel123/osc.png)

Here's what I have. The switches aren't shown here. On/off switch just bypasses the circuit, vibe/trem switch switches between shorting LED legs and grounding the gate of the 2N5457(connects to junction R13/R8). R3 can be changed to a higher value for a choppier trem(biases the 2N7000 further OFF on downswings). R16 and R17 are a dual-gang pot with each section in series with a 3.4k R. R7 is a 10k pot, series 2.4k. R13 is the trem depth pot, wired as a variable R.

As I said, these are kinda hard to interpret because they are drawn for simulation.

Duck, the :icon_eek: wasn't about parts count... Just joking about looking when you said "for Lyman eyes only".

Thanks for sharing.
Quick couple of questions DM123.
Why the smaller 6k8 emitter resistor? I ask because Mark Hammer mentioned something of this ilk in a previous thread.

Are you using a 10k pot for R7?


I see now why it sounds like it does with 2x series concertina splitters.

Heres what's on my magnabread board right now.

(http://i.imgur.com/BbjlqZt.png)

This is great stuff guys, thanks for sharing.
Duck, I guess the way I wired my switches is not optimal because there is a brief moment when lifted off the ground, huh? I will try your other way next time, looks good, thanks.
I've been busy creating an OD/dist circuit and sanding/refinishing a church pew for my wife's dinner table but I think I'm ready to jump back to the vibe and try all these cool ideas.
Kipper, I like the mosfet idea, maybe double spitting 'tinas and a 4-stage coming up next. Throw in some tremolo blending and a 2-speed footswitch...  8)
DM123, thanks for sharing, your double 'tinas make the warble so much that my 2-speed box might need some depth control up topside after all... that should make duck a little bit happier  ;D

Kipper: Yes, 10K depth pot(series 2.4k). I ended up with the smaller emitter R (and different bias R on the second stage) through simulations and adjusting for unity gain with the pedal on.

Anybody tried my "chorus" setting? It's just one extra C and R to implement it.... It isn't quite "univibe", maybe 50% of the way there?

Ok so what where you looking at in the sim to adjust the emitters R?
Gain comparison? Between emitter and collector outputs.
Sorry to ask so many stupid questions.

Thanks for the reply.
Rich

Comparing pedal input to pedal output.

DMichel - whwere does your univibe connection actually go, is that the output or does it connect with the output? or something else?

your J1 - the diagram shows the gate hard to ground, and the "osc" running through three resistors to ground. (personally, I think one resistor to ground would suffice.) ......

and, seeing as you are simming these, can you do me a favour? invert the oscillator output to the second stage, so the leds are 180 degrees outta phase, and tell me wot happens. and, if you can, find a combination of cap values (your C1 and C4) that make the most something/anything happen.

kipper - does your osc run for the full pot range, does it run with a lower stop R (R2), does it run full-pot with a 100k in? also, hah-ha, sucks. and your humpty cap is (C4) 220nF, does it fill the hump or not? [also, also, when they are electos, turn C9 and C11 the other way, and take R10 and R11 to V+ instead of ground, and that cap string will be 100% correct.]

ben - nothing useful new, sorry.



I think we need to get deadastro in to post, so's we can get the thread up to at least 35 pages .....

Quote from: duck_arse on May 27, 2016, 11:07:00 AM

kipper - does your osc run for the full pot range, does it run with a lower stop R (R2), does it run full-pot with a 100k in? also, hah-ha, sucks. and your humpty cap is (C4) 220nF, does it fill the hump or not? [also, also, when they are electos, turn C9 and C11 the other way, and take R10 and R11 to V+ instead of ground, and that cap string will be 100% correct.]

I think we need to get deadastro in to post, so's we can get the thread up to at least 35 pages .....

"kipper - does your osc run for the full pot range?" Sure does.

"does it run with a lower stop R (R2) "
Yep down to 1k with a B50k speed pot. Makes it go slower at slow and faster at fast, like ray gun fast.

"does it run full-pot with a 100k in?" Yessum it do. runs at full pot range too.

humpty cap is (C4) 220nF, does it fill the hump or not? Thanks yer i got that. brb gonna try and hump it.
what pots works best for me B25k That humps best to my ears.
What pots dont work for me 10k and less (went down to 2k) and 50k plus pots (went upto 500k) YMMV.

[also, also, when they are electos, turn C9 and C11 the other way, and take R10 and R11 to V+ instead of ground, and that cap string will be 100% correct.]

hmmm using 1uf box caps actually, but taken on board.


"I think we need to get deadastro in to post, so's we can get the thread up to at least 35 pages ....."
Did you mean pages or leds? :)

I get my coat.

for info still using a 4mm spaced vactrol 5mm super bright led and waitrony KE10720 (std tayda) LDR
encased in white heat shrink so i can see whats going on and // led.

How am I doing?

ps If you look at top right hand of DM123s drawing D.A you will see his R5. Also shown bottom left in the splitter

Oh and good luck England for tonights football game. By which I mean the beautiful game otherwise reffered to as Soccer.
Not the qAussie rules rugby / football mash up.

Hut hum......  ??? :icon_biggrin: :icon_lol:

Version 3 with notes

(http://i.imgur.com/9cJov8E.png)

Can't say for certain becuase its getting late and I dare not crank the bigger tube amp much more but it sounds like the mofet versions oscillator noise comes through more than the bjt splitters do.
Let me know if you try it guys.

Rich, I just tried MosVibe V3 and the noise is there when turned up loud. I also noticed you have the output coming from the 2n7000 source (I think?)
Is there a reason for that that I should be reading up on? Duck's appears to be coming from the drain and then thru a buffer and then out the source of the buffer.

Anyway, my main concern with my latest test is that I still can't get it to slow down! This is my first attempt with the 4-stages and I used the above schematic with 1uF caps, etc.
I changed my speed pot to 100k, still didn't slow down, then I just put it in series with a 470k (570k total) and still no slowing! I can always get it to go super fast with less resistance but I just can't slow it down no matter how much resistance I throw at it.
What am I doing wrong?

Yer your right there's a mistake there. Take the output from the drain cap 220nf. Make it smaller like 100nf to 10nf. And you can change the roto/vibe pot to 10k again.
To make it slower speed use 100k speed pot. Series 1k resistor.
Sorry chaps

Not sure if this has any bearing, but looking at the concept of speed control,

• The ideal method of adjusting the frequency is to use a triple pot, to control all three phase shift sections. This is not always practical, so only one section is usually adjusted.  It is usually best to adjust the last phase shift section, rather than the first one after the amplifier, as it will usually afford a wider range of control.

From  Randall Aiken's site (http://www.aikenamps.com/index.php/designing-phase-shift-oscillators-for-tremolo-circuits) .

You can always use your old 3 stage PSO with the mosfet splitter too.

Thanks for that Rob.

Some where's here Jon Patton did an comprehensive PSO thread too.

The source output mistake was copied from the mosfet splitter I nabbed off the net. Ooops.

Thanks guys, very helpful, I'll try swapping the speed pot with R16 10k and see how it responds.
I read Rob's link and learned a little more about it, thanks Rob.
I put 3 100k pots in between the 4 caps in the PSO? LFO? POS? what's it called?
By adjusting two of them to a certain point (I didn't measure them yet) I was able to use the third to control the speed and got it down to a much slower speed than before, I'd guess about half.
The trade off is that the top speed is not quite as fast and sickly as before. Gotta rack out now, maybe I'll try some more tomorrow.

According to Robs link try putting speed pot at R11 Ben


Edit.
We won 2 to 1. Not that I know anything about football. Ive got to say that has to be a first England winning anything against Oz.

foopball? sorry, was there a game ....... ?

we'll have no triple pots in this thread, thanks rob. we're letting DMichel get away with suggestions of dual gang, but he's new here. and DMichel, yes, I am a goose, it struck me in the shower this morn, your odd fet connections are for the simming, to stop the osc, as per your "hard to understand/follow" note. for penance, I tried your chorus connection, sort of. but from the source of the mosfet, 2 stages, to the output like-a-lpb1 gain stage. different, swooshy, especially with the two phase clock.

kipper - I almost missed your leds. not in parallel, unless with a resistor each. always! you can use a lower value for the depth resistor, and higher for the vactrol, if you like, but 2 resistors. or else.

and ben - go back to that circuit I posted with milllions of parts, and look at the way I've done the depth pot and led connection. try those values, up or down the value of all the caps to suit. it is quite probable that your very low stop resistor is wot makes it run so fast.

[edit :] also note I'm using 22k stop in the led string. I noticed a lower value there affected the oscillator range, dying at both ends of the pot. it might hold up with a lower value there, but didn't see the need to try.

I would say I haven't had the slightest off osc noise coming thru, but that would be tricking. I've got the osc feeding an LM358, with some sine-shaping and inverting to provide the out of phase led drive. very quiet, also very swishy, more complex swoopsings. also, more parts!

and it doesn't seem to matter for the lyman cap if you take from the source or the drain as far as I can tell, or even both (I think I've tried every connection combination of two caps and two ldrs there is there), as to the phinal phased sounds, they just get mashed together again anyway.

Kipper, when you say 4 stage mosfet magnavibe, do you mean you're running 4 magnavibes in series?

Ok Duck, I'll give it a shot. I had to hand copy your schematic because you use that blackout background to prevent people from printing out your designs, don't you? Deadastro too. Pretty tricky!

Marcos, kipper and Duck just mean we've been trying to add an extra cap and resistor to the POS.. yes, the POS, that's what I call it now. Some have said LFO, now I see PSO, so as long as we can make up any name we want for it, I'm going with POS  ;D

Hey Markus.
I refer to the 4 stage phase shift oscillator seen in reply #68.
The four stages are in the oscillator. I'm not using four concertina splitters seen on the right of the schematic one only.

Duck haha what game?

I might just try the series LEDs instead. Or else ?????

I just simmed the 4 stage PSO and it wouldnt start unless I had a 100~200k in R16 reply #64
Ben.

I'm not super at simming stuff. Not sure if it was a quirk of the sim why it wouldn't start or the values used. Hence changing R16.
Changing the feedback/bias resistor R9 to 1M5 can make a difference too.

I'll breadboard it later and let you know if it has a good speed range mate.

cool. thanks kipper. I went back to my 2n5088 Q1 with an MPSA18 in the 4-stage POS. I didn't have any 680nF so I used 470nF and Duck's resistor values. It sounds great and goes very fast but I still can't get it to go slow enough for my liking, even with a 500k pot it only slows to a certain point and no more. I can see where a triple gang pot or even dual gang would help but i think I would rather just try to adjust the resistors a little here and there, find a compromise

Ah got it. Thanks for the replies. This is getting interesting.

Also, Rich, in the mosfet version, do you mean output should be taken from the point between C4 and the LDR, correct?

You should be fine taking it from c5 to as long as it's go a cap there. You will probably get more highs from C5 as proved by the Lyman cap in another thread.
If there's no cap you will get thumpy trem and no vibe. Been there too.

Have fun Markus

Ben I've seen 4 stage PSO without the extra resistor, google it. Or just take it out on the breadboard see if it achieves a slower rate. It's such a personal thing with the speeds.
You can always try a different lfo. Like the one from the folie a deux schematic I sent you now that will go slower than my wife thinking about making a coffee.

I'm thirsty.

Kipper, I don't think I'm quite at that level yet, with the U1a, b, c, d's and stuff.
Here's what I've been learning, if it's common knowledge feel free to skip to the video:
oops, edit:
It seems like maybe the smaller cap values in the POS make it go faster/deeper and the larger values do the opposite so I'm trying to find a happy medium. Right now I have 4 1uF caps with Duck's resistor values, 250k speed pot with 2k2 stopper.
Here's a comparison with the double waggler:

Hey Ben
Is that POS slow enough yet?
And for information to build just one of the lfo's for the folie a deux you would need just u2c and u2d and associated componants.
Dual op amp 6xR 2xcap 2xpot 2xdiode and a switch.
Ooops and an LED for the Vactrol.
I hope you get it sorted mate.

todays updated circuit, both colours:
http://i.imgur.com/ttV7WpH.png
no colours:
http://i.imgur.com/vZGuVNv.png

I've put as many of "the things" in the circuit as I can think of (although I thort of an uther connection today .... tomorrow's update?), but no switches. new depth method, too. I thimk it should be clear how to join the dots. go easy with the feedback pot, it can make you a bit sick.

the phase1 stage has a cap across the feedback resistor, calculated by 1/2*pi*R*f. the f in question is the highest freq of the lfo/psssso/osc, mine was 9Hz-ish. this is meant to take the yang outta the waveform, producing a cleaner sine wave. sounds nice, can get some double-speed effects, but you need to tune the caps in the phase sections. I'm still waiting for an adult to come and tell us how.

ben - the lyman PSSSSO- you should be able to just shove in a set of 4 caps the same value, and it should cover the full pot-range.

Where does stage 2 get its signal from please?

today, it should be fed from the "stage1_out" point. tomorrow (the connection I forgot to try), it may come from Q1 source.

Some observations in comparing the different versions I've tried on the BB:
In my V1 and a few others, the POS Qc gets v+ only thru the LED's and resistors.
In Duck's V24.1 from the other day it gets v+ thru LED's and resistors PLUS a 12k parallel. That resistor kicked my ass when I popped it in! Holy penguin bait, Duck Man! I instantly got so seasick that I almost puked up my kippered snacks!
It's not present in your V24.2 but then you also have something called an I.C. thing-a-ma-jig in there... so I don't even know what to do with all that... but thanks for making it white so I can print it.

My latest BB as seen in the vid was tested by my brother last night, he agrees the range is acceptable but I'm going to keep working on the values and see if I can get some more range out of it. If I can get a nice range of speeds from slow to fast, I might want to work on the depth range. DM123 double LDR phase stages maybe? Is that the trick to making the pitch bend way over?

ben - in your vids wit der two blue lights, they look to be inconsistent/missing/odd beats. is this just from camera artifacts, or do they really go inconsistent. and are you yet happy with the range on "the new"? if your 1uF's are too slow, drop the 68k and the 82k both to 56k, maybe.

did you get any coffee yet?

[edit :] finally, he's seen the light. boom-tish, again. actually, the 12k is there giving the V+ to the collector and doing all the work, all the other junk is just hanging on extra. seesick, huh? wait till you go double reverse two stage with full feedback.

Wow! I think you're right, it might be defective, I'll have a listen to it later, hopefully just camera artifacts, whatever those are.
I want the thing to go really slow when turned down at the slowest it can go but I also want to be able to turn it up really fast. Right now the 2k2 stopper is as fast as I can go, with a 2k stopper it stalls out before it reaches top speed.

Do I need BC549 to make your version? Right now I'm using MPSA18, or would a 2n5088 work just as well?

Oppy amps ain't so scary Ben.
I haven't breaded the dub1 vibe yet.
The 12k collector is cool. I'll prolly put that in all future models. It strengthens the POS.
Keep those kipper snacks down dude.
As for the higher speed I could be wrong but I suspect the led is flashing so fast you can't see flashing, it appears to be full on all the time.
I'm awaiting email response on some stuff from DA.
I have a sea sick project for you both in development. More Kipper goodness in the sea.
Be warned op amps involved. Ben mate I'll give you some guidance on how to breadboard it.
Ducks not always that keen on oppys either.
The lfo on the new addition goes that slow between pulses that the missus had time to make me a coffee this morning.
Put the bloody flags out. I'm gonna savour every drop.
Refreshed and ready for my day off. National holiday. Yip yip.

Well, this POS is getting closer, going reasonably slow now and top speed is acceptable. I have 4 1uF caps with an 82k and 100k plus the 250k pot and a 2k stopper. Turn up the speed to max and it is right on the verge of stalling, which I think means I would have to use these very same pots and resistors right off my breadboard if I build it... or use a trimmer in there somewhere.

I don't think it's just speeding up to the point that I can't see it blinking, it's more like it goes from kinda fast at the full turn, then if I wait a couple seconds it starts to just get brighter until it simply stays on.

I am trying a A100k for the roto knob. Might as well use it if the knob is going on top of the box because the user then has a choice to crank it to full on tremolo, pretty choppy too.

My double waggler does have a a stutter... oh well, I guess I should get busy making a new board for it.

Quote from: Ben Lyman on May 30, 2016, 01:11:13 PM
My double waggler does have a a stutter...

Out-of-context quote of the day.   :)

Quote from: bluebunny on May 31, 2016, 03:09:49 AM

Quote from: Ben Lyman on May 30, 2016, 01:11:13 PM
My double waggler does have a a stutter...

Out-of-context quote of the day.   :)

I wonder if it's cuz I put my two LED's parallel instead of series? Anyway, since reading duck's advice I have them in series on the BB and it does work better, no stutter so far, and much more waggle too!

BC549 - I just pulled mine out, and it measures 250hFE, so probably one of the most ordinary (lower noise) transistors around. any B or C BC54x transistor should work, or your 5088/9's which I am unfamiliar with.

and if your led is "....then if I wait a couple seconds it starts to just get brighter until it simply stays on." your oscillator is dying and stopping. this is how they do it, generally. the 82k and 100k can both go down some, and should help. but if you still have less than 10k in the vactrol led's stopper, it's going to mess with the speeds. show me your full oscillator circuit, with values, and I'll give it a go on the bb. nothing else to do.

two leds in parallel - but always a CLR for each, or they will fight.


americans puking kippers - our work here is done.

Ok Duck, I'll draw it up ASAP.
I see a few things that might need changing now that I look closer, lemme know what you think.
EDIT: Whoops, R18 is 270k, obviously I had some trouble thinking that one out, I meant for it to be 470K. I'll fix that on the BB and report back
EDITEDIT: Nope, seems maybe I tailored my circuit around that R14/R18 pot/resistor combo. For R13 stopper a 4K7 keeps it going at top speed, but top speed is just a little slower than superbadassness
(http://i64.tinypic.com/208tl5e.png)
My dad used to keep our pantry fully stocked with cans of smoked oysters, sardines in mustard or tomato sauce, and... yep, kippered snacks... mom couldn't stand it... history repeats itself, neither can my wife... sorry babe...

Here's the updated BB schematic. I've gone over it several times and I'm pretty certain it's correct.
I now have 2K7 for R13 stopper, next value down made it stall out so 2K7 is the compromise. Top speed is acceptable, slower speeds have lots of good pulsating action.
R15 "Trem" knob starts with pitch modulation only, then blends the tremolo in with it, then far side is only tremolo, pretty nice too, but not super choppy.
(http://i65.tinypic.com/16kcoso.png)

here: http://i.imgur.com/sfOfpZP.png

and here in colour: http://i.imgur.com/6tGyf1a.png

Mr Lyman, please try those values, tell me faster, slower, just right. also tell me what value caps you have (1uF, 820nF, 680nF, 560nF, 470nF). I was using electros, so I have one fixed leg going to V+, but for those playing along using poly's or plcc's, take that leg to ground. values shown gave a full 500k pot range (!) with no stall, and minimal droop. I dunno what taper you'd use, tho.

erm - everything changes the speed ranges - transistor hFE, feedback value, fixed legs, the 12k. and the current through the led string not only shifts slightly the speed, but also affects the dying, in a bad way. I tried a BC549, then threw in a BC548B, ~250, so any transistor better than "really ordinary" should work.

so for a single phased led, this osc works good. but, if you look the anti-phase leds 24.2 schem variant, the osc drives the opamp, so doesn't vary with led brights. it also ends up a much cleaner sine, less yang.

nice vid, again.


the "great, great" Lou Christie also worked on a two stage vibe, he even wrote a song about it ...... WARNING: may contain some falsetto.

I really liked the last video. Just curious, what if you blend the output signal with the clean signal?

marcos - have a look at the circuits in reply #81, above. that shows nearly all the inputs and outputs you can use, join togther as you like. you don't need to have the two-phase led flashers, you can just flash one led at two ldr's if you want the simple life.

"the last video" - I take it you mean ben's, not lou's?

Duck, thanks for the explanation.  Little by little, I am learning more and more.
Closest cap values I have to those are 470nF and 1uF, nothing in between.
I am using 1uF monolithic ceramic but I also have some electro's on hand if needed.
I will alter my circuit as you described and see how it goes, thanks for that.

Marcos, from what I understand, the Uni-Vibe "chorus" setting is just that: blending a dry signal into the wet, so I tried it a few times awhile back with not much success. I thought it would make the effect sound like a chorus pedal but I couldn't make it do very much. It still may be worth a try for one of you guys who knows more about how to do it, I just want to keep the parts count down as much as possible.
BTW, the circuit I posted above also needs a make-up booster stage, I will probably just use another LPB-1 like last time.

Quote from: Marcos - Munky on June 01, 2016, 11:25:40 AM
I really liked the last video. Just curious, what if you blend the output signal with the clean signal?

The signal at the base and emitter are in phase with each other.

The signal at the collector is out of phase.

This effect works by rhythmically blending the signal from the emitter and collector together. The more closely the signals are matched, the more phase cancellation is heard. The phase cancellation is heard by us in part as a pitch vibrato, but imperfect level matching (which is inherent since one of the signals is always partially blocked by the LDR's varying resistance) produces slightly different notches, which is what we hear as the "phaser" effect. Also, omitting some of the out-of-phase signal essentially does the same thing. The 100K pot* Ben added for his tremolo blend forms a voltage resistor with the load at the input of the next device, lowering the output of that stage, and causing less pitch vibrato/phase cancellation. My Blue Warbler uses a switch for going to tremolo but a switch is obviously incapable of blending.

Blending the input signal would, in essence, be exactly the same thing as blending the emitter signal as the effect already does, with one important difference: the guitar will not be buffered by the transistor in such a case.

*I'm going to hop in here with a couple suggestions.

1) The blend is slightly unpredictable as wired. You also have no pulldown resistance. A single resistor at the output (e.g. 100K) (a) sets a predictable cutoff frequency for the output capacitors, so that they sound the same regardless of what amp or effect this is plugged into and (b) will prevent switch pops when you hit the bypass.

1b) Even better would be adding a buffer after that stage so that the impedance is guaranteed to be constant. FWIW, given the nature of guitar circuit impedances (usually between a few hundred K and the 1M of an amp), smaller resistances after the LDR will both be less variable (50K||1M is a much smaller difference than 1M||1M) AND will produce a deeper variance in effect. 100k is a decent compromise with the VTL5C1 but the ideal value depends on your LDR.

2) IMO it's better to use the LDR to vary the collector output rather than the emitter output if you're going to have a tremolo mode. Why? Because you can produce a small boost by very slightly decreasing the resistance on the emitter. Nothing major, just something like 6.8K instead of 7.5K. As it stands, the tremolo mode has signal loss because the emitter is never at exactly 1x gain and the LDR reduces it from there.

3) The depth pot, as wired, has a very limited range, which you found out a few posts ago. You can't go too high with the resistance or the LFO craps out. It also can't go to 0 depth without shutting off the LFO. It also affects the duty cycle, and affects the total speed range you can achieve at different depth settings (you want the collector resistance to be FIXED, not variable, to get the maximum possible speed range), and IIRC the rate indicator LED blinks backward to boot. There's a fix that reworks how the LFO works -- you can see my way of doing that here (https://docs.google.com/document/d/1aM2U7PL7NiMd_RaaV-7s5epvqRBPM0ZSbdbKHx96tRw/edit) -- it's only a couple extra parts for the LFO and corrects every issue with PSO LFO in this effect (except the inherent speed range limitations of this kind of LFO).

Can't really comment much on the "rotary speaker effect" aspect of this effort, except to say that trying to get a rotary effect out of a single stage phaser is quixotic -- a rotary speaker cabinet contains a drum and two horns, with the drum and horns rotating at different speeds and affecting different frequencies, which is much more than a signal transistor can handle.

Ok you wombat sniffer  with you 18k what the heck.
i made my pso into vers x 2
like this
http://i.imgur.com/6tGyf1a.png

but i didnt have an 18k so patched some in series close enough to not be scientific.
I didnt like the 100k depth pot so i changed it for a 50k. sounds better to my ears.

using all box 1 uf caps x4
all leg resistors going to gnd

edit;
i left the 1M5 from C to E.

i like this version it is smooth and has a nice wide range of speeds as slow as id want to go and as fast as I'd need.
Aint you a clever clogs.
I go now do some antiphase led stuff.
thanks.
I think Ben will like how slow it goes too.

Thanks Jon! Very good schoolin'! I've learned enough for today, anymore and my brain will melt.

Okay Rich, I have to try it now for sure. Hopefully later tonight

Lots of learning too! I'm not a BB guy, so I can't try your ideas. But I'm keeping an eye - maybe both eyes :icon_lol: - in this thread, I'm really interested in the results.

see? now Jon's told you, youse all got's to do it!

today we have the dual-rate version, using 1uF and 470nF caps. it comes in two versions, the faster and the slower, depends on how you wire which caps on the switch. you can use a 3pdt to select one range pot or the other, so you can use different tapers for each pot - something I'm NOT going to go into.

http://i.imgur.com/kK7fO2j.png
if you are no fun:
http://i.imgur.com/Gjo7Fuf.png

if yer toppest speeed still ain't top enough, I tested R4 down to 1k5 and it still didn't go cronk, but yr pot 'feel' will be screwy. a funny thing about the speed pot while testing - if that leg was left open, while fiddling with stop values, the oscillator went to a maximal slow freq, and just kept running. so, diminishing returns with increasing pot values.

and as for the tremolo/rotate pot. if you want the choppy trem, easiest is to just open the connection between the collector and phase-cap. the pot is now non-functional, the trem only runs at one depth. so, you could use a switch pot, when switched off you get the chopp-trem - but the pot will need to be wired backwards, otherwise you'll go from the chopptrem straight to no trem, then more trem w/ clockwise turn.

ah-hah I hear you exclaim! there is another way - you can take the pot apart and cut the conductive track close to the CW lug. then short the centre and CW lugs, and when you rotate the pot full CW, the wiper loses contact, the phase-cap goes out of circuit - full chop comedy trem! 24mm pot would be "best" to try, I'd suggest.

@ben - faster or slower?
@kipper - wombat sniffer?

I like it Duck. Top speed is great. Is there anyway to keep that top speed and make it go a little slower?
Sorry to be so demanding! It's actually a perfectly acceptable slow speed, I just thought it might be cool to go even slower if possible.

Kipper, I tried 1M5 too, but Duck's 2M2 helps it work better.

And Duck, I'm still trying to catch up so I'm a bit behind, still working on yesterday's, or was it two day's ago? anyway, if I use mono-ceramic caps in the POS, can I do it like this with the 47K to ground?
Also, how about adding a booster transistor w/volume pot instead of buffer? Pictured here is the LPB-1 like I did last time. Any suggestions to improve and/or simplify it? I'm all about simplify... less parts, etc.
(http://i66.tinypic.com/9sgmmt.png)

the circuit in reply 102 is the one for if you have only 470nF and 1uF mono ceramics, want to pull them to ground, want a high and low range, with a pot each - and now you want to use 47k? I won't be responsible for the repercussions, let me tell you.

that top speed and slower - is this with the rev X.Z values, or the Y.Z values? (it might be possible to get a lowwerrr slow, but at the cost of a gap in the range betweeen the hi and low pots.)

the caps need to go to a low-impedance point, they don't care if it is V+ or GND or somewhere in between. electo's are meant to be more positive at one end, so it is easy enuff to pull them up to supply + end, and down to gnd the - end.

I think your Q3 might be making too much gain, I reset mine for fairly low gain. if you can find a spot on the volume pot that seems unity right across the trem/rotate pot range, replace it with 2 resistors, to simplify. does the trem pot affect the out volume?

and when you've got this all sorted, we can get onto the double phase version! you beaut!

Oh sorry, I should have specified just how far behind I am. I'm still on this one:
http://imgur.com/6tGyf1a 

I really like it too. I have all these values but I'm using 1uF monolithic ceramics and put that 47k to the ground.
Is there a reason to use electros with this? I have a few tantalum 1uF and some ancient radial electro 1uF also.

I will try to catch up to post 102 soon and see how it works for me.
btw, I think my 2n5088's run about 500 HFE so that could be an issue too.

Yes, trem pot affects volume but I might be able to find a compromise, I like that idea of eliminating the volume knob. The trade off would probably just be that when turned all the way towards "vibrato only" the volume would be a little above unity, which is probably okay.

umm... rev X.Z values? Y.Z values? sorry, I don't understand  ???

I'm using that PSO too Ben.
I really like it too. Using a 50k depth pot / 10k though.
And I'm using a super bright clear 5mm led for vactrol and to skew the sine wave a bit I have a red 3mm in series.
I also have a stash of 1uf taunts that have been begging for a use for ages thanks for the idea.
Not sure what my hfe is on the PSO tranny 2n5088......
A few changes to my concertina splitter though I'm still using a B10k trem pot. I found your 100k pot a bit hard to set, somehow it had a very narrow band for a pseudo rotary effect. Just my ears prolly.
If you find the trem side a bit choppy turn the depth pot down a bit.
You may find a little less discrepancy in the volume levels from with a 10k trem pot from trem to vibe.

Cool beans Rich. I gotta try some different color LEDs, that's a good idea now that I am running them series instead of parallel like before.
Ya, the 100k trem pot is hard to blend the two effects perfectly but I also like the choppy trem capability. Maybe I'll try a 50K pot and see if I can still achieve the same choppiness at the far end of the knob, and then a 20K pot, and then decide.
Right now, if carefully dialed in just right, I can get a lot of sounds from vibrato to feaux-rotary (Fotary?) and thick tremolo.

Let us know what you settle on mate.

It's great Duck, I think this is the best yet. I can't decide which one to go for, the previous version works great to and has less parts but maybe if I can fit this one into my existing double waggled box. I don't know yet

the last one posted, Y.Z, is specifically for your cap values/types, and your need for speed, both ends, and your liking for seperate rate pots. it has an alternate wiring for a faster top speed, too. it runs faster and slower than the one with electros, X.Z.

Ok, got it. I have tried both and I like both a lot. The last one, Y.Z is on the BB now and works great, two speeds and everything. I think I might have to go back and try X.Z again because it is simpler, easier for me to understand. I might make a single speed "normal" pedal or try to wire it up in my current double waggler box with two speed pots but both pots being equal just to keep it simple. I have to admit, I have a very hard time understanding how to wire the switches in this kind of situation and looking at switching symbols in the schematic isn't any easier for me. Also, I like the pot values better because I don't even have 250k pots, I'm testing with B500k w/510k resistor parallel and would rather not do that in the pedal

I'm back (after some very important fish-catching) and keeping it simple this time, no double speeds. Here is the current breadboard schematic. I want to build it with 4 knobs, well... I don't want to but I have to. The trem knob is working great for me but it means I need a booster and volume knob. Also, Duck's 4-stage POS is working so nicely that it really needs the depth control to appreciate how great it is.

I'm way behind the times and I want to get on to the double-phaser gadget but I need to build this one first, working on a layout that has 4 pots in a row mounted right on the board the same way I did Gus' "Silicon Supa Fuzz Like" with 2 pots. I hope it works out, I like the way the pots and LED bezel hold the board suspended in place.

Duck, you said you think my LPB-1 booster stage (Q3) might be too high-gain or something, and I agree it definitely doesn't need to be so loud. How would you go about adjusting it so it can have just a slight volume boost? Right now I just have that 100k in series (R19) to tame it some.

(http://i63.tinypic.com/35i9bn9.png)

Try 330k R21 and 3k3 R23 ditch the 100k R19
And go from there.?

well, as kppr points out, your R19 100k will be voltage dividering with the Zin of the boost (about 100k), so half signal reaches the bboosstt. also AKPO, reduce that stages gain with the resistor ratio, and then see if it needs volume pot or just 2 resistors as fixed vol cont.

did you hear about the fisherman with one arm? he caught a fish this big (holds up one hand).

If you are a big big tree, we are a small fish.

You can't catch a Kipper. He has to be smoked, just not the magic blue smoke.

Thanks guys, that works. I'm working on some different cap values now, I went back to the original 220nF input and output caps last night. It's getting there slowly but surely.

Duck, I did hear about that fisherman... wasn't he the guy that invented cave drawings?  ;D

One time in Alaska we brought a girl on board for a 10 day fishing trip... She came back with a red snapper  :-* :P  :icon_rolleyes:

REV24.21, corrected and updated to replace those in reply 81:
http://i.imgur.com/dPp4VDr.png
and B/W
http://i.imgur.com/JrXvw4v.png

still waiting for kipper's names (when he stops gibbering about the trees).

what's the easiest way to catch a kipper?

Get him out of the smoke house.
I'm in........

have someone throw it to you.

Hey I got 18nf caps?
weird or what.........

bee zar. yello?

Yessum Yello.....

Been a long time in the making. it's my first 4knob pedal and board mounted pots to boot. At least I have a working layout now in case I ever want to make another pedal with 4 knobs. It's not exactly what I set out to make or what I expected but I'm very happy with the results. It is a sonic mangler with its own personality. My so called "tremolo" knob is something else, I think Jon may have tried to explain what was going on but I'm not sure. Either way, it's pretty cool and makes some very useable sounds. Big thanks to kipper for sparking the idea for the trem mod and another big thanks to duck for the great POS mods  ;)

Great stuff Ben.
Thanks to this quest you now have the honour of having a cap named after you too.
:)

sounds pretty good there, "three vibes" Ben. are ya gunna show yr layout?

I haven't yet measured the box out to save my 4 knob drilling layout.
Did you mean the component  board layout that I made in DIYLC?
It's probably not nearly as good as something you could come up with, it's like a long rectangle with all the pots mounted in a row.

here is the finished something, not exactly a magnavibe (and a project not exactly finished).

circuit here, in colour:
http://i.imgur.com/wjw7Ats.png
and B/W here:
http://i.imgur.com/KR9aFCa.png
this version replaces the now deleted circuit from post #117.

here is the perfboard layout, on black back (it is quite large):
http://i.imgur.com/9S3a8W1.png

for those wanting a light background, ask, and I'll send the diylc.diy file, and you can mess the colours to your hearts content.

the boss told me no corner holes, 24x17 holes, and the name, so take it up with him. I think the circuit dia matches the board, if you spot an error, let me know, it has not been verified yet. it is intended for "5 minute vactrols" style vactrols. there is an alternate placement for the feedback cap if a squeel stop R is needed, also shown.

ask kipper nicely, I think he has posted a sound clip matching this version (you REALLY don't want to hear mine). we next doing vibe with envelope-controlled rate. stay tuned.

That's great, I got some catching up to do. What if all I want is a simple phaser without all the extra stuff? You know like a Phase 90 or Small Stone... but easier and less parts?!?

I think this was the one in question

https://www.youtube.com/watch?v=cPEF2HK4TB8

You got a lot of catching up to do Mr L.

Simple phaser you say. Less parts, thats not easy.
I'd be inclined to go for more parts ,more phase stages, probably around 8 stages to get a good depth of phaser.
Since theres not so much trouble getting the 2n5952 in the US id try the phase 100.

If you want to I could further develop, with your input, an op amp phaser i've had on the back burner. As soon as I'm done with Ducks devonian and the Enveloped tremolo I got going on.

what "extra stuff"?

easier than a P90 would be a P45. you could even hack in your special psssso oscillator.

QuoteI'd be inclined to go for more parts ,more phase stages, probably around 8 stages ....

now yer talkin'.

I think I have all the parts for a P90 except the D1 zener. is that important?

you can use 4V7 or 5V1 or 5V6 or 6V2, if that's what you have. otherwise, use two red leds in series, K to ground. the voltage you need depends on the fets you have.

Thanks Duck, I don't have any zeners at all. I am having a hard time understanding the data sheets, trying to learn what a zener is/does differently than others.
I have 1n5817, 1n400X, 1n34A, 1n270, 1n4148 and 1n914.
Should I stockpile some zeners as well?
What's a good common type, if so?

err - three red leds (1V7 * 3) or two other colour with higher Vf.

if you are buying in stock, you want 400mW in 4V7 and 5V6, which will cover nearly all 9V, biased-fet circuits. you might only be able to get 1W these days, but they're fine.

Thanks Duck, I'm guessing I should get a few 1n4732 and 1n4734.
I see they also have 1n4733 5v1 zener, maybe a few of those too

Just finished firing mine up.  I must have gotten lucky with my parts.  Grabbed a superbright red LED and one of the LDRs in the drawer, and it worked like a charm.  Nothing needed changing or tailoring.  Works great.

Instead of a vibrato-to-tremolo pot, I simply stuck in a 9k1 resistor and a toggle to short/unshort it. Nothing special about 9k1 other than I had plenty and didn't want to run out of 10k.

This is a nice little circuit.  The vibrato is certainly not the sort of seasick effect you might get out of a phaser or chorus with the dry signal lifted, but it's a nice coloration; the kind of thing you don't mind leaving on for a while if you're playing rhythm.

The option to transform it into tremolo is a real plus in my books.  Note that the entire LFO and depth range will be useful for tremolo, while only a portion of each of those ranges will really be useful for vibrato.  I would imagine that, were one to use two cascaded stages to produce a wider pitch shift, you'd still be able to hear the effect at slightly slower speeds and lesser depth.  But with one stage, the LFO needs to be relatively fast and furious for the effect to be clearly heard.

All in all, though, big return for a few parts, a small hunk of perf, and a few hours of tinkering.  Mine is going into a little 12V "lunchbox" battery-powered amp.

Excellant. A mini magnatone amp.
RESULT........

Mark, can you share the schematic that you used? There's been so many experimental posts lately

Quote from: Kipper4 on July 30, 2016, 03:42:48 PM
Excellant. A mini magnatone amp.
RESULT........

"The Midgetone"

I used the very first one you posted in this thread, without any gain-recovery stage on the output, just straight off the second 100nf cap.  I hadn't realized until you asked that there had been such a succession of changes over the 7 pages.  Apparently the first one was good enough for me.  If the subsequent ones offer any improvement, I would imagine it to be marginal, or simply an adjustment to the quirks of the parts used.

cool, thanks. Glad you like it. The only change I feel is important to the first one is to wire the LEDs in series rather than parallel. This was Duck's advice and it does improve the wobble steadiness. The reason for two LEDs is not only for the option of mounting one on top as a rate indicator but it affects the other LED within the vactrol so as to make it a little more "seasick"
My first scheme with the LEDs in parallel achieves the affect but also causes an irregular wobble.

The 9k2 resistor is perfect for throwing on a switch, that's how one of my earlier boxes is set up, actually a 10k trimmer adjusted to taste.

My latest one, the one with 4 knobs as seen in the last vid, is kinda weird but I like it, because I used a 100k pot for that control. I can go from plain vibrato to some weird but very musical and useable wibble-wobbles

Nice thread!

I finished on this morning, and have something to add:
I use BC548, and trying to "pushing" it with a LPB1 in the front, you get a really nice overdrive.
I'll share a video soon

when i had built one of these years ago, i ended up using one of them 10mm waterclear led's. worked great... plenty of wobble, and more volume than the smaller led's. seemed to be a little phasier too... maybe from needing more current?

maybe itt was the acid... i dunno ;)

Hi everybody

Great inspiring thread  :)

I'm breadboarding my own magna/rotary but I can only get a very subtle pitch wobble. I only have standard red leds.

You have any advice on leds? Will leds with a higher mcd give more modulation? do Ldrs react better to certain colors?

best i got was what was posted in the post just before your last post ;)

its a funky circuit. it wobbles way more at higher speeds than lower ones. but i think brighter leds seem to work better.
been forever, i sold mine to a bud who took it on tour to europe and never came back. yet, anyway ;) that was a couple years ago.

Quote from: ljudsystem on November 28, 2017, 02:50:11 AM

You have any advice on leds? Will leds with a higher mcd give more modulation? do Ldrs react better to certain colors?

its a mix of both really imo....but make sure you have them covered with heatshrink...

no light pollution..for full effect...

Higher MCD in a LED usually means its emission is focused on a narrower beam. If it misses any of the LDR's active surface, it might be no better than an weaker, ordinary LED.

(http://i63.tinypic.com/35i9bn9.png)

using this as reference [because it was the first I came across looking], if you fiddle the value of C4 you can, to a certain extent, compensate for led funnynesses. ifn you run the led too bright, the ldr won't swoosh from low R to high R as much.

are your standard leds diffused or waterclear or tinted? are you using a winky indicator led as well?

[oddly, just today, I've started at this circuit again.]

As my experience, this design IS per se very very subtle.
It's hard to get some strong/deep vibrato or tremolo from it.

Someone says that they have good resulta with green leds.
But, I think it's more important wich LDR are you using and the mentioned light isolation

Thanks for the advice guys.

The leds I'm using now are diffused red leds but i'm thinking of hedding down to Kjell och co (the swedish equivalent of Radio Shack) and they have leds in all colors, sizes etc. but they only sell them in bags of 100 I think otherwise i would buy one of each and experiment.

Yeah, the 10n cap really helps, the first vibe i built rolled of allot of high end.

I actually  went completely overboard with the project and split the signal via a AMZ splitter, hi-passed one and lo-passed the other and sent each signal to its own magna/tremolo to simulate the Bass/treble rotors  ;D

BTW

What is a "winky" led? ???

Quote(the swedish equivalent of Radio Shack)

If it was truely an equivalent, you wouldn't be able to find one.

QuoteWhat is a "winky" led?

I think he means an "effect on" indicator that blinks at LFO speed.

I recently built a version of this circuit. I tried many different "roll your own" opto couplers. They all react quite differently. I made a simple change to the circuit. I wired the LFO to be full depth all the time. Then for a depth control I put a 250K (100K worked very well too) pot in parallel with the LDR and I found this gave me better control over the depth.

For reference my circuit was basically Jon Patton's Blue Warbler without the envelope section. Instead of a switch for tremolo mode I used a 100K pot with a built in switch which allows for a lot more variation in the wobble.