LFO ticking and "anti-ticking"

[birt]

On geofex is an article about phase inverting. ( http://www.geofex.com/Article_Folders/polarity_reverser/polarity_reverser.htm )
there is also an idea to use a square wave LFO to switch the phase inverter at great speed to get a ring modulator sound. that made me thinking.

if you would split the signal, use an LFO triggered inverter on one half and bring it back to the other half. you would get a tremolo right? because when the inverted signal is at full it will completely cancel out the normal signal. but my guess is LFO ticking can never be a preblem in this kind of circuit because it wil be canceled out by the other phase as well. am i right or is there something i'm missing here?


bert

[Processaurus]

A couple days ago I was messing around with this idea, strangely enough, with a boss OC-2.  Huh?  Heres the schematic.  This thread got me thinking about a part in the circuit that uses the same voltage controlled phase inverter type of circuit as in the geo article, and the element that controls the  phase is a JFET (Q8) that shorts out the non inverting input of IC5B (and makes the signal's output phase inverted) It uses a logic controlled phase inverter to help make the octave sound, but I tried disconnecting the GE diode (D10, which bleeds the control signal into the audio, which helps the octave, but not our phase inverter experiment), and hooking the JFET that does the phase control up to an audio frequency 9v square wave.  Listenign to the output of that stage, it definitely does the ring mod thing, but theres a lot of high frequency gnarliness from the abrupt transition between phases.  The triangle wave sounded a little better, less hash-ey.  The bleed through was actually mild, but it was there in the background.  Maybe dialing in the V1/2 voltage real precise could reduce it... I think I tried LFO frequencies, but I can't remember what happened .
To kill the signal in the out of phase configuration (and get a normal choppy trem sound), rather than invert the phase, one way I can think to do that is to put an equal resistor to R3 (referencing the Geo article) in series with the switch or JFET that shorts the opamp + input to Vbias.  I'd still use an LFO wave form with sloped edges to control the phase, though, because any transition in an audio signal that is very sudden sounds like a click, because its forcing the speaker to move quickly.

[gez]

but my guess is LFO ticking can never be a preblem in this kind of circuit because it wil be canceled out by the other phase as well. am i right or is there something i'm missing here?

If you're only modulating one chain, then there can't be any cancellation of any bleed-through from a LFO.

[brad]

What an interesting idea