New Phaser Design - “Causality 4” – Built with you in mind!

[pinkjimiphoton]

mark.... my brother.... words to live by!! ^^^^^^^

haven't tried with any fuzz yet, still working out a couple minor little buggies, but last nite i turned the range down and depth some and messed with the regen... and man, into my typical blackface hotrod princeton it was THICK as molasses , almost like a .... i dunno what. it was definitely moving around the signal in some peculiar and completely unexpected ways.... could definitely get that classic throb, but it was more like doing mescaline as opposed to lsd25 *ww1 era triplanes flying thru the old chromostones and ridiculously organic in a very peculiar way.

i'm toying with the idea of putting this in a crybaby or morley shell with an @55 load of knobs and switches.

i'm addicted.

the biggest issue i have is getting the taper right for the speed pot. it's really touchy when it gets fast, that rubber really hits the road.
dino hipped me to this page: http://www.diystompboxes.com/analogalchemy/emh/emh.html
which i never knew existed... looking like a 1m pot with a 2.7M and 51k tapering resistor should get me in the ballpark. i need to spread out the last 10% a lot more.

mark, do you think this could be adapted to my fuzz idea?

like... make a multi voiced fuzz, and have two fixed and two swept stages with this kind of oscillator?

i'm wondering if maybe while this is still partially on the breadboard if i should try taking the blinky lights with some photoresistors feeding the input of some fuzzulars?

man. jus when i thought the madness was ending....












* don't try this at home    kids, and don't ask how i know this stuff...
edit: M

[Mark Hammer]

Well, I don't know what you used, but LFO speed controls nearly always cry out for a reverse-log taper (which Rick does indicate in the schematic).  If that does not get you the dialability you need then I guess the next thing might be to use something like a 200kC pot, where those last 50k ohms are stretched out even more, and if you need slower speeds, strap on a 270k-300k fixed resistor in series, using a toggle.

As for adapting it to "your fuzz idea", I'm not sure which variation of "that idea" we are talking about at the moment, given that a number of suggestions rolled in after the OP.  As I recall, your intent was to switch/morph between different kinds of fuzz, as opposed to simply modulating one fuzz.

Maybe you want to take a peak at the Ibanez Flying Pan for some inspiration.  That one combined a phaser and panner, such that the phaser was sweeping at one speed, and the phased signal was then swept between left and right outputs.  My Line 6 M5 includes a model of it.  I was never all that partial to it because I found the combination - especially the panning part, not subtle enough.  I found it interesting for 20 seconds at a shot, but irritating after that.

On the other hand, let us say that a Flying Pan-like circuit fed two different fuzzes, whose outputs were mixed for a mono out, with the phaser going on in the background, and the panner morphing the final output between one fuzz and another.  Is that a little more up your alley? (keeping in mind that a phaser->fuzz sequence is not quite as stark and dramatic as a fuzz->phaser sequence)

[pinkjimiphoton]

Well, I don't know what you used, but LFO speed controls nearly always cry out for a reverse-log taper (which Rick does indicate in the schematic).  If that does not get you the dialability you need then I guess the next thing might be to use something like a 200kC pot, where those last 50k ohms are stretched out even more, and if you need slower speeds, strap on a 270k-300k fixed resistor in series, using a toggle.

what i did was go to a 1m pot, with a 50k linear as a vernier for the last part of the sweep... can fine tune the fast speeds easier, and still get pretty slow to the point of almost sounding like a flanger. gonna open a 50kl pot, and wipe out the carbon at the bottom of the track... that way, when the 50k pot is all the way down, it will be out of the circuit.

On the other hand, let us say that a Flying Pan-like circuit fed two different fuzzes, whose outputs were mixed for a mono out, with the phaser going on in the background, and the panner morphing the final output between one fuzz and another.  Is that a little more up your alley? (keeping in mind that a phaser->fuzz sequence is not quite as stark and dramatic as a fuzz->phaser sequence)

yes, please.

[pinkjimiphoton]

the phaser's done..

i modded it a little bit into a 6 knob 2 switch 4 led monstrosity with a remote jack for pretty much any expression pedal... works great with a roland ev5!

the on/off indicator is ultraviolet purple, left footswitch is in/out with true bypass and a grounded circuit board input in bypass so no background noise when it's off. other footswitch kills the dry signal to change it from a phaser (red) to a vibe (blue.. this led changes color).

but wait, there's more.. in addition to the afforementioned leds, the two inner ones pulsate back and forth at whatever speed the lfo is running at, and if you use the expression pedal input, you can see the speed change. it's hip. those are yellow and green blinky blinkys.

i added a 6th pot, fine which lets me fine-tune the upper range of the speed... it gets real fast when dimed, and the sweep is a little difficult with the speed pot alone. fine acts as a vernier to fine tune the speed. i opened up the pot and made it a "reverse no-load" pot by oblitterating the carbon track on the BOTTOM of the pot...unlike the top in a guitar. that way, when i turn it all the way down, counterclockwise, it takes the 50k fine pot out of the circuit and leaves the speed pot, which i'd doubled from 470k to 1 meg... so this thing can not only phase super slow, it can almost flange as well. and do tremolo. and vibratto. and chorusing. and phase the living phuck out of the synapses betwixt your brain cells. so anyways.. the most complex thing i have ever undertaken, here ya go... the causality 4 phaser, photon edition... stupid pedal trick and knobs to come...

the expression pedal jack is one of them plastic taydas, i used the switch connections on the jack itself.. when you pull theplug out, it defaults to a closed circuit with the 50k fine pot. i used only the tip/sleeve connections, no ground connection. worked out great. had just enough room to fit it between the two footswitches, and it actually is a good place for it..

avoided having to add any more switches by modding that pot. worked great too.
thought about using a 3p3t toggle with a 100, 10, and 30u cap, even built it up, but didn't install it. with the 1m speed pot, i can get it to phase REALLLLLLLLLLLL SLOWWWWWWWWWW, and with the vernier deal, i can dial it in easily.

tried making a tapered pot, but it just plain didn't work as well.

and yes, the knobs are crooked, intentionally.. two reasons... one, it let 'em all fit in a 1590bb without me having to get too smart and figure out exactitudes of measure far above my paygrade,  and also cuz i think it'll look cool  when the knobs are on ... kinda sine wave-y..

anyways... again... thanks rick for this great project, and everyone else who contributed every speck of knowledge i've gained here.. this is THE coolest thing i've built yet.

peace

[deadastronaut]

SPT vid please...

cool build man, ive been looking at this for ages and never got around to it....but now i need a phaser again. i love em.

[tubegeek]

man. jus when i thought the madness was ending....

And what exactly made you think THAT?

[Mark Hammer]

I made myself a Ross/Ropez some time back that had to have just about the widest sweep I have ever heard from a phaser in my life.  It was like the A/DA flanger, for crying out loud.  Just kept on going and going, and sounded like the phasing in the ELO tune "Strange Magic".

How'd I do it?  There is a 10k resistor used to limit the current from the LFO in the Ropez.  I dropped it down to 9k1.  One doesn't want to reduce such resistors too much since applying too much current to the current-control pin can fry them.  But it warrants experimenting with trimpots or other resistor values in OTA-based phasers so that he control current can be increased juuuuusssstttt a bit more to produce a wider sweep.  One can always reduce the sweep width from that maximum, if desired. 

Naturally ultra-wide sweeps are for the slow stuff, and bubbly settings demand a narrower sweep.

[pinkjimiphoton]

SPT vid please...

cool build man, ive been looking at this for ages and never got around to it....but now i need a phaser again. i love em.

i'm gonna talk to joe gagan and get a nice 50k wah pot from him with the cool gear so ya get more sweep, and put it in a chrome crybaby shell.

it works GREAT.. i'm using an ev5 right now, but the resistance is too small... ya want 50 or 100k.

this is like a vibe, phaser, chorus... i swear to god, almost flanging.

this is definitely on my board as of tonite.

vid as soon as i'm able... it would take like, 4-5 hours to go thru all the stuff this thing will do, it's sick!!

[pinkjimiphoton]

used this last nite live... on almost every song. and got different sounds out of it every time.

i ditched the ev5 for an old crybaby shell, stuffed a 100k hotpot in there and one jack, with a footswitch to bypass the exp pedal.

it is @#$%ing sick.

anyways... stupid pedal trick as promised

http://www.diystompboxes.com/smfforum/index.php?topic=106323.new#new

[dan.schumaker]

So I have been working with the tagboardeffects version of this circuit

http://tagboardeffects.blogspot.com/2012/02/causality-4-mkii-rick-holt.html#comment-form

Having an issue with this phaser. I have it hooked up to my test rig and have sound coming through, and the Led's light in time and depth with the pots, but no phasing. I checked all my voltages to the ones Rick posted and they are all in line. The only issue is pins 5&7 on the LM13700. I am getting voltages of .58-.73 on those pins. I tried tracing back but am not seeing why I am ~5volts short there.

Any thoughts?

[Govmnt_Lacky]

@dan_schu

My best advice is to ensure that you have all of your jumpers installed (there is one between Pins 5 & 7 of the 13700) and to make sure that all of the trace cuts are there.

Post voltage measurements as well. 

[dan.schumaker]

I'll quadruple check when I get home, but I am sure all the jumpers are there.  I know for a fact that the one that connects 5 & 7 is there.  I traced voltages from the 9V input to those pins.  I was getting ~5volts up until the 33nf cap, then after that it dropped to 0.5V.  I re-flowed and replaced the cap (just to take that out of the equation) and the voltages are still down.

Here are my voltages (this is with speed at min, shape middle, everything else max):

NE5532
1. 1.29v to 8.46v
2. 3.87v to 5.49v
3. 3.82v to 5.58v
4. 0v
5. 3.90v to 5.52v
6. 3.76v to 5.70v
7. 2.89v to 7.21v
8. 9.49v

TL084
1. 4.19v to 5.41v
2. 4.16v to 5.45v
3. 4.15v to 5.43v
4. 9.10v
5. 3.82v to 5.10v
6. 4.12v to 5.50v
7. 4.15v to 5.49v
8. 4.13v to 5.52v
9. 4.20v to 5.53v
10. 4.08v to 5.31v
11. 0v
12. 4.11v to 5.42v
13. 4.14v to 5.46v
14. 4.16v to 5.44v

LM13700
1. 1.26v to 1.35v
2. 0v
3. 4.02v to 5.40v
4. 4.06v to 5.39v
5. 0.42v to 0.56v
6. 0v
7. 0.43v to 0.57v
8. 4.12v to 5.42v
9. 4.10v to 5.39v
10. 5.10v to 6.62v
11. 9.49v
12. 5.12v to 6.62v
13. 4.17v to 5.42v
14. 4.14v to 5.45v
15. 0v
16. 1.26v to 1.35v

Thanks

[Govmnt_Lacky]

Remove the 13700 (hopefully you used a socket) and check resistance between Pins 5 & 6 and then between 6 & 7 on the socket. I am wondering if you have a short to ground somewhere there... 

[dan.schumaker]

I checked resistance between ground on those pins.  Everything looked good, so no short there.  I tested voltages on both sides of the 33nF cap off of pin 7.  On the pin side, I was low, on the other side, I was getting 4.7-5.3 volts.  I tried just replacing that cap with a jumper, which gave me the right voltage at pins 5&7, but still no phasing.

I'm thinking this is one of those that I should just retry building (maybe with a different layout) and see if it happens again.

Thanks

[Kipper4]

So I've built this and have room to spare on the perf for the addition stages daugter board.
Question is can I make it switchable and if so how.
Thanks

[frequencycentral]

It's earlier in the thread. Can be done with a DPDT switch.

[Kipper4]

Thanks Rick
I've found it. Sometimes it takes me a while
Rich

[nickbungus]

Just a quick one.  Thanks Rick.  It was a really enjoyable build but what a pedal?  I built the Mk II, etching the PCB, then built the 2 extra stages on vero.

It sounds amazing.  You can dial in what you want with the five pots, but what I love about it is the tone you can achieve with the subtle settings.  I hate a phaser that sounds like you're at an airport when you stop playing.

Thanks again!

[Kipper4]

Mid build  causality 6 and I cant see how to wire the regen pot since I'm using the parity switch.
Ahhhggg help.
meantime i'll trawl through the thread
thanks for any enlightenment
Rich

[Kipper4]

post deleted still no joy