"Sonic Death Ray" Phaser - a phase insurrection!

[doc_drop]

So, I was told this thing goes, "Swwwwwwwwwoooooooooooooooooooosssssssssssssssssshhhhhhhhhhhhhhh! "
But, it sounds more like "WooooooowWoooooooooooooowWoooooow" to me. What's up with that?

Rick, I know the ROG Tri-Vibe has a sweet sine wave shaped LFO. Maybe you should look at that one?

I am definitely going to build one of these. It is too sexy not to!

[slacker]

That sounds great, I like the flangerish ringing in the first clip, almost like it's on the verge of self oscillating.

[igerup]

wow, that sounds cool and far out.

[frequencycentral]

I had another idea about how to implement parity modulation. What if we add a single phase stage in the regen path, not fixed, but modulated by a single FET driven by it's own LFO? That way the regen signal would get flipped over between in phase and out of phase thus creating parity modulation?

[earthtonesaudio]

I had another idea about how to implement parity modulation. What if we add a single phase stage in the regen path, not fixed, but modulated by a single FET driven by it's own LFO? That way the regen signal would get flipped over between in phase and out of phase thus creating parity modulation?

Implementing that as a phase shift stage would be interesting; because the "polarity" would be frequency dependent.  An alternative idea, somewhere between this and the LED/LDR method posted eariler, would be to modulate a JFET instead of the switch in a polarity reverser type circuit.

[frequencycentral]

Parity modulation LFO redesigned, perf'ed and tested, home-made vactrols rolled. And the main PCB arrived today from my PCB man.....



......and some perf-porn for Slade:

[frequencycentral]

Here's the new parity mod circuit and layout. A little more graduated than the previous version. Incidentally, this circuit can also be used to replace pretty much any pot configured as a voltage divider, though you might want to limit the dark resistance of the LDRs by using resistors in parallel. Imagine - LFO control of BM tonestack, or of mixing between two signals, or..........

[frequencycentral]

PCB layout verified! Just hooked it up! This thing sounds awesome - even quieter than on breadboard. I can't wait to get it boxed up now......

[frequencycentral]

The more observant amongst you will have noticed that the FETs are having sex. This is the secret of good phasing IMO.

[Slade]

Fet-sex, ha?! You vouyerist cyborg!

[Brymus]

Not just sex.
It looks like a full blown orgy 
Are you sure El H didnt do that layout ?   

[frequencycentral]

This is how I am proposing to implement the (quite complex) regen options:



The two regen inputs are on the left, one stage apart. The DPDT selects either parity modulation (from the parity modulation board) or fixed odd/even parity (selected by the SPDT). Then the regen pot and limiting resistor. Finally the 6 regen taps (each two stages apart) selected by the 1P6T rotary switch.

[Slade]

Hey, why don't you make the switch to select manual parity or parity modulation into a 3pdt stomp?
Would be nice to have that option while you're playing

[frequencycentral]

Hey, why don't you make the switch to select manual parity or parity modulation into a 3pdt stomp?
Would be nice to have that option while you're playing

Wow what a good idea, how could I not have thought of that? 

[Slade]

Because it's a young'n idea.

[tuckster]

Is it possible to get a ultra long sweep like one can get out of a Whetstone Phaser? http://www.youtube.com/watch?v=zLKvcuQSyHY

[tuckster]

Is it possible to get a ultra long sweep like one can get out of a Whetstone Phaser? http://www.youtube.com/watch?v=zLKvcuQSyHY

I think I'm going to tinker around with my causality4 instead of building a new phaser. But is it technically possible to get such a long sweep with both "Rick Phasers" (without substituting the whole PCB)?

[frequencycentral]

Box drilled, graphic applied, panel populated. Now for the off-board wiring nightmare to come.....

[Slade]

Awesome looking pedal
Love those nippleds...

[deadastronaut]

Hmmmm,, nice phasers on stunning..