Finished the Polyphase!!! Presenting The Resotron

[Morocotopo]

Hi all.

Finally finished my Polyphase semi-clone. I christened it "Resotron" because it has awesome resonant sounds.

It all started here:

http://www.diystompboxes.com/smfforum/index.php?topic=100570.0

and here:

http://www.diystompboxes.com/smfforum/index.php?topic=99403.0

and here:

http://www.diystompboxes.com/smfforum/index.php?topic=102176.0

The thing in action:

Thanks to all who helped with this build! Mark, Jimi, Scruffie and many more. Later I´ll post the build details, but couldn´t resist showing off... err, showing it to you guys.

[Liquitone]

Nice! well done
I especially like the envelope sound with the sweep rate still going, and I like the lower feedback setting better then the high feedback, it gets too gimmicky then.
But I have that issue with all phasers and flangers. (apart from the small stone maybe, I love the high feedback setting on that one.)

[deadastronaut]

very cool...i like the env settings too...nice.

[armdnrdy]

Great job Ariel!

Question:
Without reading through all of the posts, Did you ever try a different vactrol besides the CLM8200/2?

I'm wondering if a VTL5C3/2 will work close enough. As you know the CLMs are non existent. 

[Morocotopo]

Thanks guys!

Armdndry, no, I only have 8200/2´s, don´t have any other dual optos.

[kaycee]

That's really cool sounding and looking, great work!

[Mark Hammer]

VERY very nice.  The time constants on the envelope part are very musical.  That is, the feel of the envelope control is expressive, and doesn't fight the user in any way.  The envelope-driven sweep of the phaser, when there is no LFO modulation is also quite lovely; almost filter-like but different. I will note that the issue of Polyphase you cloned has 6 stages of phase shift, where the current issue unit only has 6 swept stages (can't tell if there are any additional fixed stages).  I really like the sound of the older POlyphase I repaired last fall, and this unit lives up to the sound of that one.  Kudos.

I adapted a Phase 90 I made to have some envelope control, although all I did was parallel an LDR with the Rate/Speed control to have some envelope-control of modulation rate.  Fans of the P90 will note that the value of the 1M resistance between the trimpot and the JFET gates can be altered to adjust the "offset" of the phasing; that is the frequency range where the notches are produced.  Were one to parallel an LDR with that resistance, it would be possible to produce some of the auto-sweep sounds that the Resotron produces, although not likely with as much control.

If you can implement it, I also recommend installing a dry-lift to get vibrato effects.  I did that on my P90 and modulating the speed of the vibrato by picking strength is quite nice as well.

[Slade]

That sounded delicious!!!
Congrats. Really looking forward to build one.

[pinkjimiphoton]

ariel, that's freakin' awesome.

i still can't seem to get this polyphase running here. we need build docs man!!

[Morocotopo]

OK, thanks guys.

Mark: yes, the feel of the envelope is very musical, doesn´t get too abrupt or feel hard to control. Also, no ripple. About how it compares to a real one, no idea, never heard one, but according to you is similar. Good! The thing is really vocal, for lack of a better word, very vowel-like sounds. Why didn´t you tell me about the dry lift before?  Eventually I´ll try it.

Jimi: Get the one you have working! it´s a great FX.

My final schem:



Later I´ll post the details about my schem and the layout and PCB files.

[Scruffie]

Great job Ariel!

Question:
Without reading through all of the posts, Did you ever try a different vactrol besides the CLM8200/2?

I'm wondering if a VTL5C3/2 will work close enough. As you know the CLMs are non existent. 

Specs are close enough for jazz, i'm going to test several options soon when madbean releases his PCB for this.

Great job Morocotopo  sounds lovely! Can't wait for the build report and obligotary guts

[StephenGiles]

It also occurred to me that the bounce circuit from the Eventide Instant Phaser would make a useful modulation tool for this unit.

[Scruffie]

Morocotopo, when you built yours what voltage did you get at the trimmer? Only I have an original in for repair and while the envelope works, I can't set it to the 6.7V specified on the original schematics, about 5V max (at which point the envelope doesn't really work) so i'm wondering if the thermistor is bad or if the original schematics have that as a red herring... although assuming they're wrong on purpose and just for servicing purposes that seems a little counter-intuitive.

Edit: Nevermind i'm an idiot, it's 6.7V after the 8k2 not at the trimmer 

[jubal81]

Whoa, just remarkable! Bravo. 

[roseblood11]

Later I´ll post the details about my schem and the layout and PCB files.

still waiting...

[armdnrdy]

Later I´ll post the details about my schem and the layout and PCB files.

Hey Ariel,

I saw that you were online today so...I know that you didn't get abducted by aliens!

Any chance on build documents? I would like to give one of these a go and verify a work alike vactrol.

[Morocotopo]

Hey guys!

Sorry Scruffie, Larry, I´m not around here as much as I used to be, kind of in tube amp land right now (finishing an AC30 with some bells and whistles) , as a matter of fact this pedal was my last one finished. But once in a while I check what all you guys are up to.
Scruffie, the trimmer I set not to 6V7 but to some other V, basically where it sounded best. Remember my build has more than 15V power, more like 16-ish. But it was in the neighborhood of 6V7, if I remember correctly. I wouldn´t worry about the voltage in the schem. I´d trim ´till it sounds good. If you can´t make it sound good, take out the thermistor cause that´s in parallell to the trimmer to ground, if it´s shorted or out of spec it can affect the voltage.

I promise tomorrow I´ll post the buld docs, if the aliens allow me to do so. They are quite bossy these green guys...but the food is nice.

[Morocotopo]

OK guys, if you want the files e-mail me at: a-r-i-f-i-g-at-y-a-h-o-o.com (replace "at" with you know what and delete the dashes), put Resotron Files in the subject and I´ll mail them to you. Tried to put them in the gallery but couldn´t log in...

[armdnrdy]

Thanks Ariel,

Email sent.

[Scruffie]

Scruffie, the trimmer I set not to 6V7 but to some other V, basically where it sounded best. Remember my build has more than 15V power, more like 16-ish. But it was in the neighborhood of 6V7, if I remember correctly. I wouldn´t worry about the voltage in the schem. I´d trim ´till it sounds good. If you can´t make it sound good, take out the thermistor cause that´s in parallell to the trimmer to ground, if it´s shorted or out of spec it can affect the voltage.

I amended that post, I was just measuring at the wrong spot, it's 6.7V after the 8k2 resistor, not at the trim, so I got it set as it should be