control voltage generator - which circuits have this

[DWBH]

I was quite interested in this thing (http://topopiccione.atspace.com/PJ16TPCInvisibleTouch.html) and I'd like to know more circuits that could be, eventually adapted to this Invisible Touch

thanks!

[dano12]

One of my favorites is the Q&D VCF. It is a Voltage Controlled Filter--increase the voltage and its like turning the filter up and vice versa:

http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

You can also have the CV out drive and Led/LDR pair or optocoupler to replace a pot on just about any effect. Nelson posted a PDF where he showed how to adapt CV outs to a variety of interesting circuits:

http://www.diystompboxes.com/smfforum/index.php?topic=46926.0

[Ry]

I breadboarded the Invisible Touch over the weekend...it worked very well for me.  I'm dreaming up what to insert the CV into now...

[DWBH]

One of my favorites is the Q&D VCF. It is a Voltage Controlled Filter--increase the voltage and its like turning the filter up and vice versa:

http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

You can also have the CV out drive and Led/LDR pair or optocoupler to replace a pot on just about any effect. Nelson posted a PDF where he showed how to adapt CV outs to a variety of interesting circuits:

http://www.diystompboxes.com/smfforum/index.php?topic=46926.0

Oh, so the CC thingie is like a voltage generator?
I'm a dumb ass

[dano12]

One of my favorites is the Q&D VCF. It is a Voltage Controlled Filter--increase the voltage and its like turning the filter up and vice versa:

http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

You can also have the CV out drive and Led/LDR pair or optocoupler to replace a pot on just about any effect. Nelson posted a PDF where he showed how to adapt CV outs to a variety of interesting circuits:

http://www.diystompboxes.com/smfforum/index.php?topic=46926.0

Oh, so the CC thingie is like a voltage generator?
I'm a dumb ass

Hi my name is Dano and I'm a dumb-ass too

Actually the Invisible Touch you referenced is the voltage generator. It creates a control voltage (CV) output that can be used to control other circuits. The easiest way to hook up a CV generator is to pick a circuit that has a CV input, hence the suggestion of a Voltage Controlled Filter.

[DWBH]

So my question should be - tell me circuits that have a CV input.

Thanks dano!

[widdly]

Wasp filter or the LPF filter on the elby designs wasp pages can be built to run from 9v and have CV inputs.

[caress]

possibility of running a cv input into a nyquist aliaser?  hmmmm...

[theblackman]

You can also have the CV out drive and Led/LDR pair or optocoupler to replace a pot on just about any effect. Nelson posted a PDF where he showed how to adapt CV outs to a variety of interesting circuits:

Why do you actually need an optoisolator? Aren't you actually just controlling a voltage with a pot anyway? (hey I'm new to this ;-))

@caress : i think moosapotamus (moosapotamus.net) has done something similar already, i think he added an envelope follower to CV the frequency on the nyquist aliaser or was that the uglyface... i forget... anyway FUN STUFF!

[caress]

oh yeah!     great...i'm going to try adding a super-duper slow LFO as well as a s&h.  i think i might just make a control box then add a cv in jack...seems like the best idea.

[theblackman]

yeah, i like the modular approach as well.

[Zero the hero]

Any OTA based circuit can be converted for CV input, think at the Small stone or a dod fx-25.
Since OTAs are current-controlled, rather than voltage-controlled, one should find an appropriate resistor between the Invisible Touch CV OUT and the control pin of the OTA used (pin 5, for example, for a CA3080).
I prefer the LED/LDR approach since this component provides isolation between the invisible touch CV out (well suitable for catching radio frequency intereference... man, that copper plate is a super antenna) and the circuit you want to control.

[DWBH]

So we can use any circuit found in here?

[Mark Hammer]

Pretty much.  A cv is a cv is a cv, and whether the cv is continuous (as with a "probe" style proximity source, or LFO) or stepped (as with a sequencer of some sort) or a "shaped-event" (like an ADSR generator) is moot as far as the circuit being controlled is concerned.

The chief concern or caveat with a cv, however, is the range of voltages.  Some things want this much voltage, and have a control range of from this many volts to that many, and others want more....or less.

There is also the same issue we face with pots, and that is whether the taper is appropriate to the way we wish to control the device.  For example, what if you hooked up the I.T. circuit to an adapted flanger such that you could "manually sweep" (in the strictest sense of the term! ) the flanger, but all the interesting changes occurred within 5% of the range of movement the antenna could detect?  So, scaling and control taper are also important, even when you've nailed the range of acceptable control voltages.

For the adventurous, I will note that any of the 391x chips (3914, 3915, 3916) used for bar graphs and such can be adapted to "quantize" a continuous control voltage produced by hand or other movements into discrete steps.  The bar-graph chip reads the CV input as if it were a signal, and provides outputs from the appropriate pin as if it were illuminating an LED to indicate that signal-level range.  Those quantized outputs can also be used to do things like switch devices electronically with a CD4016/4066/4053, etc.

[DWBH]

One other question that came to the during my sleep last night.
We can pick one control (a pot) from any circuit and connect it to a circuit like Invisible Touch, or even a sequencer, can't we?
By using a optocoupler or LDR/LED thingie, right?

But how do we do that? By connecting the led from the LED/LDR combo to the place were the lugs 1 and 3 of the pot would be? And then, one of the legs of the LDR to a resistor and then to ground, and the other one being the CC?

Perhaps I'm making this whole up, so please correct me. 

[DWBH]

Did I make myself clear?

[The Tone God]

Maybe this article will help:

Rock N' Control

Ignore the foot control and replace it with the touch circuit.

Andrew

[DWBH]

Maybe this article will help:

Rock N' Control

Ignore the foot control and replace it with the touch circuit.

Andrew

Thanks. I'll read it first thing in the morning.

[DWBH]

What if a pot has two connections and in the 3rd lug i connects to ground? Can it be done? I mean, is a ground connection a no connection (i'm afraid not..)


Yeah, I think I got it. I can take out the jacks and put a switch instead, making it in an all-in-one-box.

BUT: Should I connect the parameter control to the Invisible Touch's CV out? I mean, we have two traces here, and the CV out is only one connection...

ADDED LATER: What would be a good opto for the invisible touch + wah? I was thinking of using the wah board on that nelson's sequencer pdf thing.... perhaps the VTL5C3?

[oskar]

What if a pot has two connections and in the 3rd lug i connects to ground? Can it be done? I mean, is a ground connection a no connection (i'm afraid not..)

No, it's a VOLTAGE DIVIDER!!!
You put two variable resistances working in opposite or substitute one of the pair wiper/cw, wiper/ccw with a fixed resistor...