More uber-phaser musings........

[frequencycentral]

I'm planning another uber-phaser, dubbed 'Gemini Dual Core'. At it's heart will be two Causality 6 phaser cores, the magic will be in how they are configured. Part of the concept is inspired by the ol' Bi-Phase - two phaser cores in parallel, either of which can be switched in or out, with the dry path 'always on' - which will require the pedal to be non true bypass. I've also worked out the switching options so the two phaser cores can be either in series or in parallel. As well as the option to run both phaser cores from just one LFO, or for each to have their own dedicated LFO.

While allowing the ideas to ferment in my mind, it also occured to me that it might be interesting to run the two phaser cores in parallel - BUT - add a little inverter to the output of one LFO, so that phaser core #1 sees a normal version of the LFO while phase core #2 sees an inverted version. Then, cut the dry path. In my mind, I'm imagining that as one phaser core 'peaks' the other 'troughs', and therefore they are 'twice as far away from each other' as either one on it's own would be from the dry signal (were it present, which it wouldn't be). I'm hearing big phatt uber-sweeps in my head.

Hmmmmmm....................!

[R.G.]

Ever thought about generating quadrature sine wave or triangle wave LFOs instead of simple inversion?

[wavley]

Wow, that sounds really excellent.  I like the series sound I get when using a Morley Pro Flanger into a Small Stone and I can adjust the lfo separately. I really like the idea of inverse parallel lfos!

edit: ooh oooh, and what R.G. said!

[frequencycentral]

Ever thought about generating quadrature sine wave or triangle wave LFOs instead of simple inversion?

edit: ooh oooh, and what R.G. said!

Wot? And make it complicated? 

The more I think about it, the more I'm considering just building a 'modular phaser' in Eurorack format using 3.5mm jacks for hookup:

• input buffer section with multiple outputs
• at least two phaser cores with Bblenders in the regen paths, so that further phaser cores can be added into the regen paths
• output mixer with multiple inputs
• a bunch of LFO's with a bunch of waveshapes and normal/inverted (and quadrature?) outputs
• other stuff I haven't thought of yet

The beauty of Eurorack would be the open-ended-ness and add-on-ability. Ah insanity, so sublime, so cruel.

[StephenGiles]

quadrature  - into barberpole we go!!

[Mark Hammer]

There's one Thomas Henry quadrature design in this scanned article: http://hammer.ampage.org/files/quad-shep.pdf

...but a more articulate discussion of its application to phasing here: http://www.birthofasynth.com/Thomas_Henry/Pages/QFG.html   Note that the second link provides LFO outputs at 0, 90, 180, and 270 degree stagger.

Quadrature-based LFO-sweeps are obviously synced, and, while not the same as standard LFO sweep, are nonetheless more audibly periodic that using two unsynchronized LFOs.

One strategy to consider employing is that of having two LFOs on tap, with the option of either:

• harnessing all phase-shift stages to one or the other
• mixing down the two LFOs into a single aperiodic control voltage
• feeding banks of phase-shift stages with independent LFOs such that some stages are sweeping up while others sweep down.

Note that in that latter arrangement, it will NOT behave the same as two phase shifters in series because there is only one series of phase shift stages.  Any notches are produced at the point where phase shift and dry signal combine, and from what I gather, this would only involve ONE mixing node.  So what you'd get is the sum total of all phase-shift added.  It may be that the quirks of any asynchronous sweeping impose wild amounts and jumps of total phase shift in unpredictable places.

[R.G.]

quadrature  - into barberpole we go!!

Shhhhh... I was saving that for when he got to quadrature...  

[frequencycentral]

quadrature  - into barberpole we go!!

Shhhhh... I was saving that for when he got to quadrature...  

• other stuff I haven't thought of yet

[Mark Hammer]

quadrature  - into barberpole we go!!

Shhhhh... I was saving that for when he got to quadrature...  

Wait, so bit by bit you're going to lure him into building a Boss PH-3...in analog form?

okay, but only if at the end of it you promise to reveal yourself as a lesbian blogger.     or is that "too hip for the room" at the moment?