VICO VIBE MADE EASY

[allesz]

Hallo, I just made a vico vibe clone, and I want to share my findings about the bias of the base of the "output" transistor.
It's an easy way that sounds good.

A lot of help came from a lot of folks arond here (and in the other forum too...) in this tread: http://www.diystompboxes.com/smfforum/index.php?topic=97698.0

Bigger caps and bigger resistors (1M and 150 nF instead of 560K and 100nF) yeld slower pulses. I lowered the in and out 27K resistors to just 1K, and now the treble roll off is almost absent. If you remove that resistors altoghether the circuits starts to bleed tick tick tick to your amp.

[allesz]

Sorry, did a bad mistake drawing the schematic.
Here is the right one 

[duck_arse]

do you get enough depth like that?

[~arph]

I like that pso design, never seen it before

[Crontox102098]

Sorry, did a bad mistake drawing the schematic.
Here is the right one 

It would be better some 10K pot instead of that switch, i think... that would be the "depth" control.

[allesz]

Hey duck. Plenty of depht actually.

Did not try a pot in place of the (on off) switch.
As reported also by LuciferTrip messing with the base bias of the output transistor alters both waveform and depth. A variable voltage divider can be a nice option.
My bias gives full depth, the wave is sawtooth... like a volume swell...

What pso stands for? Public Semantic Onanism?

[~arph]

Phase shift oscillator..

[allesz]

Hallo arph. I just noticed we are in the same time zone.

I am not very expert with oscillators... this one looks almost like a inductorless wah to me... go figure

[duck_arse]

hey arph, that osc tripped me up once too. it's twin-tee, like the kay trem and the schaller trem. I found it had real low output as drawn, only about 1V p-p, much much less than the pso like in the ea ......

[vigilante397]

Sound clips?

[~arph]

hey arph, that osc tripped me up once too. it's twin-tee, like the kay trem and the schaller trem. I found it had real low output as drawn, only about 1V p-p, much much less than the pso like in the ea ......

yes I see it now.. it always oscillates and you can set the resonant freq with the pot.