DIYstompboxes.com

So I'm looking into enveloping a phaser what should I be looking to envelope?
Speed? Effect intensity?
What?
Also how many stages?
Thanks guys
Rich

Both? Must be able to switch between speed or intensity?

How many stages? More! Ok, maybe 2-4?

This could be fun, but my knowledge is limited. I remember breadboarding an MXR phase 90 once...

how about: 4 stages: 2 driven by one lfo, and 2 driven by a swept-rate lfo (up and down, natch) or an eveloped lfo, all mixed at the end?

Thanks for that.
I wonder how pigtronix does it?
I looked through the stompbox cookbook and havent found the right articles yet.
I also looked at Nelsons pwm phaser.
@DA i think I have an idea how to do that now, thanks to you.
I'm going with 4 stages rc4558 op amps. (thats whats in the video)
I'm in a pigtronix phase. its a bit like an artists blue phase but with more swirl.
I was gonna call it the dervish but its been taken. So whirly bird it is.
I'll post up a preliminary scheme later.
Bare in mind it's a work in progress so its a Q&D schematic for later cleaning up.

I'm seeing more and more envelope-controlled modulation effects, and I love it.

I'm still too broke for the Keeley Dynatrem, or the Pigtronix Envelope Phaser, or that crazy Catalinbread trem/fuzz (and I'm still too green to design my own) but I'm licking my lips.

Well you could be in luck since I'm a cheap skate. Less parts is the new black.


Q&D demo

I tried a 2 stager but it wasn't swirl enough and was getting drowned out with a distortion in tow.
So I swapped to a 4 stage. I even tried a 6 stage but was too cheap to add the extra vactrols and ran into trouble with running 6 stages from 4 vactrols. I shouldn't be surprised.
I'd really like to go with 8 stages but it has to be comfortable in a 1590BB.
So stay posted I could get some mission creep yet.

Sounds good!

And +10 for the Weezer song!

I added envelope control of the speed to a Phase 90 build, and quite like it.  It was a simple matter of sticking a photocell in parallel with the speed pot and using the a half-wave rectifier (a la Dr. Q) to light up an LED instead of feeding a 1N914.  I imagine it might be a little different with envelope control of another parameter (like depth, mix, or feedback), but the time constants have to be selected very carefully for  the envelope control to correspond to your playing in a musical way.  It can't decay too quickly or else you end up with a jarring transition.  Keep in mind that you can't perceive it as decellerating unless this sweep was a little slower than the last one and a little slower than the one before that, which is going totake a couple seconds to hear.

Envelope controlled mix, on the other hand, could have a near instantaneous attack and decay, because you'd be using it as a switch - pick hard and you hear phasing.

Heres the Q&D 1st schematic.

I tried the Univibe cap mods and it sounded muddier to me, maybe thats the univibe mojo.....

Edit; note the phaser/vibe switch
When engaged (phaser mode) it adds the dry signal to the wet (gain of 5).
The gain was a trial and error thing. I tried larger gains but they caused issues.
1min 20 in the demo

(http://i.imgur.com/5NWdWxw.png)

Quote from: Mark Hammer on July 23, 2016, 03:12:16 PM
I added envelope control of the speed to a Phase 90 build, and quite like it.  It was a simple matter of sticking a photocell in parallel with the speed pot and using the a half-wave rectifier (a la Dr. Q) to light up an LED instead of feeding a 1N914.  I imagine it might be a little different with envelope control of another parameter (like depth, mix, or feedback), but the time constants have to be selected very carefully for  the envelope control to correspond to your playing in a musical way.  It can't decay too quickly or else you end up with a jarring transition.  Keep in mind that you can't perceive it as decellerating unless this sweep was a little slower than the last one and a little slower than the one before that, which is going totake a couple seconds to hear.

Envelope controlled mix, on the other hand, could have a near instantaneous attack and decay, because you'd be using it as a switch - pick hard and you hear phasing.

Thanks Mark brilliant

"Envelope controlled mix, on the other hand, could have a near instantaneous attack and decay, because you'd be using it as a switch - pick hard and you hear phasing."

this sounds like an good idea......

The lfo as shown is very flexible speed wise. very slow at slowest and very fast at fastest, not quite ring mod but up there. So it will hopefully have a good deal of playroom with the enveloped speed mod. It depends on the envelope a lot.
cheers

Another day on the breadboard.
I'm a little nearer with a speed up and slow down feature.
Despite spending most of the day trying to mod the lfo for larger value, just so my speed pot could be a 500k. ie, somewhere in the parish of the ldr in use int the vactrol hanging off the envelope.
I abandoned that idea since i couldnt make it work.
instead i put the ldr across the positive feedback resistor in the lfo R3 schematic above and put a parallel resistor of a slightly lesser value.
I'll play some more tommorow before work then post a scheme before work.

If anyone has a working schmitt/integrator op amp lfo with a 500k speed pot that works and has a good speed range throw me a link.
i tried the p90 lfo and the bugger beat me to a dribbling mess, :icon_evil:

or even suggestions on how to change my current lfo so that it can have a 500k speed pot.
I might just learn something.

Cheers I go dribble.

ver 3 schematic.
It's not over until the whirly bird sings......

(http://i.imgur.com/MBs3Xap.png)

Hi Rich,

have a glimpse at TC XII phaser (I posted the schematic on the other site).
It uses 2 comparators instead of dual op-amp.
With its LFO you can control speed, width and waveform with resistor(s) on the program jack

Thanks F3D will do.

Quote from: Fender3D on July 25, 2016, 06:14:49 AM
Hi Rich,

have a glimpse at TC XII phaser (I posted the schematic on the other site).
It uses 2 comparators instead of dual op-amp.
With its LFO you can control speed, width and waveform with resistor(s) on the program jack

Brilliant Federico. Guess what I misread. "uses 2 comparators"
looked at the tc, then googled comparator-integrator lfo.
landed here

http://www.moosapotamus.net/files/stompboxology-mo-tremlo.pdf

stole the lfo in fig 3. played on the breadboard with the scope until i got a sine ish wave and a different speed range.
A speed range that suited the project needs more. 'cuase sub sonics aint much cop in a phaser.

Messed with the envelope some more, applied the resultant envelope resistance to the mix control and bam.
Its far from perfect. but im getting results.
I go update the schemo and vid the results
Later guys

(http://i.imgur.com/3FmpM6O.png)

The 130nf in the lfo was changed from the stompboxology value to make the output more sine ish. It also alters the speed range and voltage output of the lfo IIRC.

The speed pot value was also changed (lucky guess, thank heavens for breadboard 9mm pots)

Initially I changed the depth pot (previous schematics) to a 100k value thanks Stephen.
This is now replaced with the ldr (vact5-B) hooked up to the envelope.
All of which now serves to modulate the effect depth. so pluck that sucker hard you get more phase. Soft and you get less. Taaa Daaah.

At least I think this is what I have on the breadboard. It's been a long sleepless night.

Right, yer, eerrmm
I now need to get some stop resistors on the ldr to make it sound good.
Tweek the envelope led driver bias.
Easier said than done

post deleted

Based on your posted clip, I'm going to say that C23 needs to be bumped up to 2u2, and the Decay function should probably be something like a 4k7 in series with a 250k or 500k pot.  Trust me, you'll like the smoother transition.

hmmm. you got +9 at both ends of your 100R. R33//R34 gives your led driver gain, but taking the led//R1 to VB will then restrict its swing. and upset your bias voltage. take the R1 to supply, you might be able to increase R33. (with Mark's big value decay pot, R33 at 68k will load the cap and defeat the pot, to an extent.)

ahh, from your clip before last, I was wondering if your RC4558's driving leds were going lock-up reverse, possibly that tikking in yr prev clip. LM358's will be happy going down to ground, and won't swap output polarity when you least expect it.

[edit :] and I'm not sure you're supposed to sine-shape w/ a big cap there (130nF) - I thort that cap was just to take the peaks off a triangle.

Thanks Mark good call i've been playing with that.

Stephen I come clean. There were some copy paste errors included in the last schematic.

"I thort that cap was just to take the peaks off a triangle"
It made the wave much more user friendly so why not......

I'll take some nice scope piccy for you and send them to you.

Sorry guys

after another long night experimenting I think i'm back to where i was.
I did take R1 to supply with a 270k probably going to tweek that tonight.
That noise you can hear is probably down to my playing.

Sorry scrub that I had it all wrong on the breader.
Now I have  2u2 charge cap, 100K decay+1k stopper. 200k works too and Ive yet to experiment with that 200k value pot with regard to fade in and fade out phasing.
So thanks Mark and Stephen again.
I was wrong.

I'm settled on the enveloped depth.

I changed up some bias resistors You will see in the next scheme.
I think i'll end up with another dpdt switch for the mode switching. But hey so far I'm down to 3 pots and maybe two switchs.
Sw1 Vibe/Phaser
Sw2 fade in/Fade out
controls
Level for output
Decay
Lfo Rate

I changed the IC1 B led driver to a BJT buffer. Simply because i wanted less parts and a half of an op amp meant I'd probably try to find another use for the spare half and the bjt will do the job, take up less pcb space and parts.
So far I'm down to 4x dual op amps and a bjt.
Transistor input buffer and output amp might be on the cards too.

I took the time to try and calculate the "best" ldr for my application tonight and probably saved myself a lot of hours fannying on the breader.
I'll post a new drawing in the morning.
Thanks guys.

Daily update.
New schematic

(http://i.imgur.com/nPgg4yC.png)


https://youtu.be/fuIMBDgadbE

https://youtu.be/jHzUrvm8UR4

Are you certain of your value for R28?  47K across the full 9 volts gives you 191.4 µA which would barely be noticeable LED output and this does not take into account the fact that there is a transistor, an op amp and a LED dropping voltage from that, so the 9 volts may be more like 6 volts.

R2 should be not needed. R1 and R5, if using single pole and two leds, can be reduced to a single 150k resistor, at the opamp output, switch common.

vact5B in parallel w/ R28, maybe?

two more videos? I'll never catch up. [seems a few percents were left, not long left now .....]

Quote from: amptramp on July 28, 2016, 10:06:00 AM
Are you certain of your value for R28?  47K across the full 9 volts gives you 191.4 µA which would barely be noticeable LED output and this does not take into account the fact that there is a transistor, an op amp and a LED dropping voltage from that, so the 9 volts may be more like 6 volts.

Yep thats the value I'm using. the voltage measured with the DMM is somewhere in the ball park of 4v5~7v
who'd have thought and its working.

@DA
I realised that I didnt need R2 also. I just pulled it from the breadboard to see, straight after I put it in and knew the lfo would provide enough, but thanks.

" if using single pole and two leds, can be reduced to a single 150k resistor"
in fact its a single led that i havent had time to sketch up the polarity switching.
and I changed R5 R1 to a single 470k.
I know..... amazing but it still works. and is very much in the county of aural results needed.
More on that in the vid. Watch it next month buddy, no rush.

Vact 5B and R28 // thats how i figuered to. Given my min depth Resistance of ~68K.
calculated by putting the depth pot (100k) back into the circuit. turn the pot until the horrible thumping disipated enough to make it pleasant, measure with the DMM.
Now that's science.......:)
Gl5528 specs say 10k-20k lux and 1M dark
It was supposed to be // with vact5B but and theres always a but.
The magic just didnt happen so i series it and boom "I'm back in the room".

The other end of the scale was that with 850k~1M dark depth (vact5B) the 4 leds from the phaser/vibe section simply dont light up enough to be heard.

I think this has to do with the 470k.
theres been some serious head scratching going on. I hope I dont have anymore funky breadboard junk going on so when i pcb it, it's not that at all. Aaaagh.

Thanks for the encouregment guys. Kudos to you all.
expect another vid......... Dont look DA.
Theres nothing in there thats not in this post. 'cept a flashing led and some close up elbows.

TTFN

https://youtu.be/kBgeVZfMlUg

Guys Please help I need confirmation or denial on if this will work for vactrol polarity switching.
With reference to ver7 the Vact 5 B led hanging off of IC7 A output.
(the two leds are one of the same, NOY two seperate ones)
Thanks


(http://i.imgur.com/YODMhF9.png)

Switch is 3x3 lugs. How do we (or you) know which way it goes?

However tossing it in my head, I'm not seeing happiness.

Or a need for a 3P switch. (2P would eliminate the ambiguity of switch orientation.)

http://oi65.tinypic.com/6o24ip.jpg

Thanks Paul that's brilliant.
It's a shame I didn't see it like that.
That should work a treat.
My drawing was in fact a 3pdt. I should have made it a lot clearer.
I was referencing the numbering found in an Internet image like the 3pdt here top of the page.

http://effectslayouts.blogspot.co.uk/p/general-layout-notes.html

I'm back, and caught up. it sounds like someone swelling a church organ, maybe. or some weird auto-wah.

carry on.

This sounds good. :)

Small suggestion: You can make the design a lot less expensively by using discrete LDRs instead of vactrols. You just crowd them around the LED like a univibe bulb. Like this:

(https://jonpattonmusic.files.wordpress.com/2012/05/ledman-vs-the-cads-guts.jpg?w=250)

If you plan on putting a bunch of LEDs in parallel, you may need to match them or some of them can behave strangely. In this case, though, you have enough redundancy from the extra stages that it's easier to just use the single LED.

You may also want to consider a simple input buffer. A JFET would only be a couple parts. The input impedance is <200K right now. I can some loading on the guitar in the video and it's making it sound a little dark.

Thanks Jon.
The number of seperate vactrols was giving me a headache at the layout stage. So the discrete idea is just what I needed.
I'm going with it and intend to use an 8 pin dip IC socket to mount it on. Single led throught the hole in the middle of the socket.

Question Why do they call it discrete when its anything but in appearance?


It is loading the guitar. I've drawn up a possible solution with your idea for a jfet buffer (AMZ plageurised)

I tried it with the input buffer and it went well earlier, then i tried it with a bjt amp on the output. Hoping to eliminate a further dual op amp. That didnt go so well I'm getting a lot of unwanted noise. Hence why I left IC2A and IC1 B (dual TL072)ver11 below

Please forgive the odd parts numbering it needs cleaning up. Once I am sure it's what is needed.

I can't figure out if i need to AC couple the buffer to the IC. Do I need C5?
Thanks guys
Rich

(http://i.imgur.com/25RN2Q5.png)

Ooops quicky fix.
Yes sir I do need C5 or it jams the IC2-A buffer at the power rail (8+v)

kipper, measure the voltage on both sides of the C5. if diff then yes, else same equals no. and R27 sets the input impedance of that stage, so if it sucks, increase it. mind, I suck at opamps, so this might be bad advice.

have you tried running R9 and vact leds right off the opamp, and delete Q1 and R3? conversly, you might be able to use them to drive the leds, but shift the vol-sweeping ldr to the Q1 base, with another resistor to form a voltage divider. like der tremolo you was playing wit.

Double post removed see over page.

Thanks Duck.
Changes made based on what yous said.
I might still put the jfet input buffer back in. it sounds a bit brighter with it.
Note the new decay pot value (Mark Hammer)
New 22k stopper vact5B R28
Also changed Vact 5B led to a diffuse 5mm green.
Sens pot is gone. I couldnt see the point it was alway in one place.
New value Attack R32=330 ohms Smoother than a 50 ohms.
Also not shown in this diagram is a new switch to chose between Sqaure and Triangle wave vibe/Phaser.
altogether 3 switches 4 pots.
and whats looking like a rather large layout to do.

Thanks again

(http://i.imgur.com/oz3vG8J.png)

Heres Ver 15
Still playing with it.
Video to follow


(http://i.imgur.com/7rc36au.png)

https://youtu.be/mkzrochMohs

I'm really digging this! Will try it as soon as I get my hands on some vactrols.

These are roll your own vactrols.
for the envelope detector vactrol (dull) diffuse red 5mm led with a gl5528 ldr
for the vibe phaser vactrol super bright white 5mm led (others will work) and four gl5528 ldrs



You might need to change some of the clrs R28 and R82.
the intention is to mount the fourl ldrs for the phase stages on a dip 8 socket with the led down the middle of the socket.
I'll probably try to get some bigger (than I stock) heatshrink to cover it, although it might not be needed inside the enclosure. As Jons picture shows.
One could even go simpler and make it a two phase stage, One dual op amp less and two ldrs less, bosh.
the lm358 is important for the envelope but you can probably use TL072s for the phasing.

bosh! sounds fantastic, I think you've done it. where's the layout?

[something about ldr's, now gone to pm.]

Haha.
The first draft of the layouts done.
I'm not sure I'm entirely happy with it but it's a big improvement on the two previous attempts.

All ldrs are GL5528
Led for phase wobbling (lfo led driver)super bright white 5mm
Led for envelope detector is diffuse red 5mm.
Bosh.

Stephen
Here's the Whirly Bird with a speed mod.

indeed. is that the whirly 16 circuit unchanged? it sounds like it's done, fer sher. are you thinking of having "some switches" to switch from env'd rate to env'd depth, with a possibility of env'd both?

That is ver16. depth is on a pot, Not enveloped.
The speed is enveloped in ver16. sweeping fast to slow and vice versa.

I'm not thinking of doing a switched pcb to switch between the two versions. It's either one or tother.

Feel free to work out that switching if you want.....Aaaagh

less mission creep means it will fit in a common sized box and potentially generate sales for two models instead of one.

Phaser/vibe section is the same as is the envelope and led switching.
Maybe in future I will publish.
Take a closer squint at the drawing cake face..... :)

Heres the enveloped speed version schematic with a new speed range pot.

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




I couldn't have done it without you D.A.

ERRATA

R82 SHOULD BE 4K7
Whirly Bird Ver 15 and 16

I finally made a pcb for this Whirly Bird Fader Phaser
Shoe gazers delight

Nice demo.

I see a couple places you could refine the controls:

1. You added a pot of the wet-dry mix. I think with a voltage divider pot there, you can simply make it 100% wet/dry, which obviates the need for the vibe/phase switch -- the pot will do the same thing. Put pin 1 to Vb, pin 2 to R5, and pin 3 as-is.

2. Try with a high-output pickup or with a boost and I think you'll find that a threshold control might be necessary. The short decay was still a long time for the phase to fade out/in on your video -- this is partly because it doesn't matter how short the decay (22mS at minimum) is if the signal is big enough to keep filling the cap even 4 seconds after the strum.

3. Can you actually get 0 depth with that depth control? You might consider revising it to a voltage divider depth, to pan the LED between a steady voltage and the op amp output.

Thanks Jon.

It means a lot coming from someone who's effects, builds and playing are great.

1 great idea. next time I put it on the breadboard I'll try that.

2 I did use higher output pick ups and a booster, overdrive and a few others before the effect.
  Some with good results some not so good.
  Depending on the dynamics of the playing. the freqauncy of the notes and If chords  are 
played, and where chords are played it reacts differently. Unfortunately I've reached a point where further developments are on hold and playing style becomes important. Sadly it  will never be everything to everyone and I suspect this is true of the Pigtronix example too  despite its advanced features.
It's a bit of a compromise to be honest.

3 That sounds intresting. I'm not sure how I would go about doing that. Perhaps you could ellaborate so as when I put it back on the breadboard later i could try it.

The video is of version 15. There is no depth control as such. The depth is set by the envelope. When the envelope vactrol led goes dark the lfo slows down.

Depth
I can't remember if the ver 16 speed mod versions depth goes to 0. I'll try it again. When I try your other ideas.

I appreciate the help it means a lot.

Am I along the right tracks here Jon? or anyone else thanks
Rich

(http://i.imgur.com/0XJe8CE.png)

Bumpetty bump

double post deleted

Quite a pedal there Kipper! Makes me think of Pulp Fiction and surfer-esque songs. lol. I like it a lot. I'll have to add this to the list if I didn't already. A lot of cool sounds there.

I gots me speakers inplugged, but - is that the same soundclip twice, or did you mess the address for the second post?

My mistake Duck. i'll correct that now.

fantastic, well worth the weight to hear. clunk clunk clunk.

/\ Serious comment or not?

You Like? Dislike?

Clunk?

deadly serious, as ever, kipper. it sounds good. and, good to hear it used in a tune-length clip, rather than a single chord or two and talking. clunk is the sound of the footswitches, and you press them three in a row, hence chunk clunk thunk.

Gottya. Thanks

Clunck Click every trip.
(old UK seat belt Advert) Might be on the tube somewhere.

clik clak, front and back. old aussie yoda.

https://www.youtube.com/watch?v=nQ-IvxZiZYk

A nation of Clunk Clickers. Try saying that when you've had a few beers.

Belt up.

Quote from: Kipper4 on July 23, 2016, 11:50:14 AM
Well you could be in luck since I'm a cheap skate. Less parts is the new black.


Q&D demo

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!