help with this idea..

[dschwartz]

i made a phase 90 / tremulus lune combo pedal.. wich sounds really good!!
but i wanted to do something original..mixing the 2 LFO´s together..in order to have a pseudo random LFO for both pedals..

i tried connecting the LFO´s LED voltage from the tremulus to the 3.9M R of the phase 90 ..none of the lfo worked that way..
i thought it was DC bias coming in, so i put a big cap (47uF) to block DC from one lfo to another.. no good neither..

any ideas how can i mix both LFO´s together?

[dschwartz]

no one?
i have to add that i switch the lfo´s led´s  of the Lune when bypassed..

[stm]

Hola Daniel!

Tonight I'll try to stab this thing, sounds like a good idea to me.  I'm currently at the office.

[dschwartz]

Gracias Seba..Un abrazo desde Santiago.

[frequencycentral]

Try using a 100k resistor at the output of each LFO > join the 'outputs' of the two 100k resistors together > send this mixed signal to the LFO input of the phaser/trem.

You may need to buffer the mixed signal (the 'output' of the two 100k resistors) with a simple opamp or transistor non inverting buffer stage.

Alteratively, you could send the two LFOs into either side of a ring mod - the output would be the original signals plus the 'sum' and the 'difference' - now that would be interesting!

[dschwartz]

thanks for the enthusiasm frequencycentral...but before doing something like you posted, i think is better to make the basic thing work.

my problem is different than wanting a super duper ring oscillator sweeper..is just that my simple idea didn´t work..

few hours ago i was walking a cigarrete, and suddenly came to my mind that when the trem lun. is bypassed, instead of cutting the ground i connected the ground to the positive side of the led to turn it off. so..is no surprise that the trem lun LFO didn´t oscilate when bypassed!!. DUH!!!!!!!

well tonight i´ll prove the idea..

[frequencycentral]

thanks for the enthusiasm frequencycentral...but before doing something like you posted, i think is better to make the basic thing work.

my problem is different than wanting a super duper ring oscillator sweeper..is just that my simple idea didn´t work..

few hours ago i was walking a cigarrete, and suddenly came to my mind that when the trem lun. is bypassed, instead of cutting the ground i connected the ground to the positive side of the led to turn it off. so..is no surprise that the trem lun LFO didn´t oscilate when bypassed!!. DUH!!!!!!!

well tonight i´ll prove the idea..

HEHEHE!! I do get all fired up! Hope it works out for you........!

[stm]

I think the TL oscillator can be mixed into the P90 oscillator using a 3.3M resistor in series with a 0.1uF capacitor.  On the TL one connection goes to IC2-1, and on the P90 the other end goes to the gates of the JFETs.  The values of the resistor and cap might need adjustment.

To do the opposite is a bit more difficult, as the output of the P90 oscillator is a high impedance point (a 10uF cap surrounded by large resistors) and the led on the TL needs to be driven by a low impedance source with some current capability of several mA.  Maybe IC2a on the TL could be modified so as to have an inverting input by connecting a 1M resistor between pins 1 and 2 (instead of the jumper), then adding another 1M to pin2 of IC2a, and connecting its other end via a 0.1uF capacitor to the 10uF LFO cap on the P90.  This will affect the gain for the TL LFO, but it has the advantage of using IC2a as a high input buffer to avoid loading the P90 oscillator as well as keeping a low impedance drive for the LED.

Maybe a 3-position center-off switch can be used to perform both connections plus having the stock option in the center, like: TL LFO->P90, both LFO's independent, and P90 LFO->TL.

Hope this makes sense!

By the way, great idea to have these two FX on a single pedal.

Saludos!

[dschwartz]

well i just fixed the problem..mentioned before..and here are the demos!!!!

just phaser:
http://diynoise.googlepages.com/phase.mp3

just tremolo:
http://diynoise.googlepages.com/tremolo.mp3

tremolo-phaser:
http://diynoise.googlepages.com/phase-trem.mp3

phaser with mix lfo..:
http://diynoise.googlepages.com/mix_lfo.mp3

sounds cool!!!

[DougH]

Sounds nice!

[flo]

I like the sound of that last one! Nice, this more "complex" sounding LFO.
I remember from my analog studio days that using 3 LFO's all frequency-modulating each other and tapping into that for an "LFO" signal got pretty amazing and completely unpredictable results.