"Gemini" Dual Core Phaser project

[frequencycentral]

Another crazy FC phaser. Has it's roots here: http://www.diystompboxes.com/smfforum/index.php?topic=92232.0



Messy guts - it was a work in progress:



Inspired 'a little' by the Mutron Bi-Phase. But with serious extras:

• Two seperate phaser cores
• Two seperate LFO's
• Phaser cores can be run individually, in series, or in parallel
• Phaser cores can be swept by their own dedicated LFO, or both phaser cores can be synced to the same LFO
• When in 'synced LFO' mode, the phaser cores can be inverse swept with respect to each other
• Buffered non-true bypass - the dry signal is always there, the only way to get individual/series/parallel modes

I'll be completing the full documentation over the coming days, including PCB layouts.

For starters, here's a single phaser core, two of these are needed:

Direct link: http://dl.dropbox.com/u/967492/Gemini/Gemini%20Project%20Publish/Gemini%20Phaser%20Core.JPG



Here's the audio switching scheme:

Direct link: http://dl.dropbox.com/u/967492/Gemini/Gemini%20Project%20Publish/Gemini%20Audio%20Switching.JPG



Here's the LFO's schematic:

Direct link: http://dl.dropbox.com/u/967492/Gemini/Gemini%20Project%20Publish/Gemini%20LFOs%20Schematic.JPG



I'm pretty sure all my schematics are correct and contain the latest revisions, but I may update them over the next few days. As the files are in my Dropbox, the images you see here in this post will always be the latest revisions.

I do have PCB layouts already, but I need to update them to the current spec before I release them.

Soundclips I hear you say? Yeah, later. Monday maybe.

[Slade]

Thank you.

[Mark Hammer]

Nice work!

Former forum regular Tobias Karlsson posted his "Acephase" some 11 years ago.  (discussed here: http://archive.ampage.org/threads/1/fxgd/003969/Re_My_AcePhase-1.html )
It has a similar sort of modus operandi, except it uses FETs instead of OTAs, and stops at 4 stages per section.  I don't think he'll mind me posting it here.  It's the signal routing that makes it so tricky, isn't it?

[jdub]

Excellent work as always Rick.  Thanks for posting.  BTW, the enclosure is totally sweet, too...

[Morocotopo]

Rick, can´t wait for the audios! Looks like a super duper swish machine.
On a side note, I´ve been thinking about this: wouldn´t it be nice to have a double LFO double phaser or other mod FX, but instead of each LFO free running like in your schem, with the LFO´s in sync in some way, like in 2:1, 3:1 or whatever ratios? I suppose it´s doable with a programmed LFO, but I don´t know if it´s possible with purely analog circuits...

[Greenmachine]

Great work and thanks!

[soggybag]

Great work, can't wait to hear some sound samples. I'm having trouble imagining all of the possible sounds, like series phase shift two different LFOs.

[merlinb]

C'mon Rick, I want to hear this beauty already!

[frequencycentral]

Ok I did some soundclips. Starts off with just a single phase core, then gets more complex with dual cores, inverse sweeps, combined fast/slow, series and parallel settings. I was gonna list whats happening in each part, but........

http://dl.dropbox.com/u/967492/Gemini/Gemini%20Montage.mp3

Tele Custom (HB) >>> (Big Muff for the driven parts) >>> Gemini >>> Valve Junior >>> Shure SM58 >>> Wavelab

[radio]

Congrats

That s the first phaser  that has vowel qualities.

[frequencycentral]

Congrats

That s the first phaser  that has vowel qualities.

Thank you Jean-Marie. Some of the most 'vowel' sounds are achieved with both phase cores synced to the same LFO, with the second phase core in LFO invert mode, then offsetting both the range pots with respect to one another. I've been thinking that it might be fun to make a 'stuck phaser' and use a joystick's X and Y axis to control the two phase core spectra. Completely useless as a guitar effect, unless we can figure out a tredle that works left to right as well as front to back.........

[pbard]

Greetings Rick,

Do you anticipate posting a PCB layout for your fans?


I'm on the verge of building another C6 and morphing the pair......

[nexekho]

Completely useless as a guitar effect, unless we can figure out a tredle that works left to right as well as front to back.........

I've seen one that yaws as well as pitching, think it was a Fender fuzz wah or something.

Edit:

[LaceSensor]

Looking forward to a full set of project files for this. Fine work. Like a Lovetone doppelgänger cool

[Dr Jones]

Any chance we'll see PCB layouts anytime soon?

I was considering building or buying a Phase 90 until I saw this. 

[Haynesarama]

Hi There

I was planning on building this phaser this evening.
Where have the schematics gone?

Thanks
Michael

[frequencycentral]

Hi There

I was planning on building this phaser this evening.
Where have the schematics gone?

Thanks
Michael

I've recently had a bad experience with a forum member supplying a clone of one of my designs to one of my distributors. Which led me to the decision to limit the amount of information I share on some of my designs which put food on my table and a roof over my head. This affects only a very small proportion of my published work on DIYSB, but Gemini is one (SDR is another). Sad situation to have to be in, as I've always been all about the sharing, but when folks take the piss..........

[tubegeek]

Ok I did some soundclips.

What an outstanding range of excellent sounds - that is quite the stompbox!

[Govmnt_Lacky]

I've recently had a bad experience with a forum member supplying a clone of one of my designs to one of my distributors.

Sorry to hear this Rick 

I do find it odd that the "imposter" happened to shop your design to one of the distributors that you use. What are the odds?

You have given SO MANY great designs to the community. It is a shame that someone took advantage of it! 

[Haynesarama]

Hi Rick.

I'm really sorry to hear that.
That's like stealing bread from out of your mouth!!
How disgraceful that a forum member would
do this when it's not their design and that the design was
kindly submitted to the forum by you for others to use for themselves
And not for profit.
I've really enjoyed your designs over the years (especially the sub mini's)
and have found them a great source of learning.

As a consolation the regular forum members greatly admire the work
That you have shared with us and the designs that you bring to the table
the said forum member could only dream of (or steal)

I'm annoyed also that I ordered all the parts to build the pedal
And as a result of somebody's dishonesty I'm out of pocket £50

Also what are the chances in the person selling a stolen design to one of your customers.
It's a small world we live in!!

Kind regards
Michael