Quadrature VC-LFO

[drapdap]

Hi Yves!

Just built this recently, works perfectly, one of my favourite things now...
The 4 leds still missing, i need to finish that, and i messed up the arrow,
but anyway...

Thought i'd say a thank you!

róbert

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[drapdap]

Also have a question: Would it be hard to add CV to the direction switch?
I have lots of fun just messing with that...

[yusynth]

[drapdap]

[dstrength]

I'm no expert, but perhaps this will help.

The CMOS switches Yves is refering to are widely available with pretty decent data sheets. Maxim makes nice ones...vishay has some pretty affordable ones. Something like this:

http://www.vishay.com/docs/70049/dg401.pdf

is about $3.00 US. There are certainly cheaper versions...just make sure to select one where the input is triggered by the gate voltage (5v), and where the power supply is compatabile (+-15v).

From there, you can pretty much tie directly to the pins as identified on the datasheet. The only other thing you might want to do is a place a decoupling capacitor (like the 100nf Yves uses next to all his Opamps) accross the power rails in close proximity to the IC.

[yusynth]

The DG403 shown on the datasheet will suit your needs (see the application part, fig.9

[drapdap]

Great, thank you for the suggestions!

Anything against using something cheaper like a CD4053?
Matthias used these for the LPG switchboards he was selling recently, so i'll buy some tomorrow, and try to get it going...

robert

[yusynth]