[sdiy] NEWBEES are alive and kickin' !

[Peter van Hamersveld]

Yes,

No, we did not give up.

After some thinking, and considering, we decided to start REALLY simple.
So we (Peter) soldered a very simple square generating VCO, consisting of:
2 capacitors
2 NPN transistors
4 resistors
1 trimpot parallel to the source to fake a Control Voltage from a keyboard.

it worked :)
though not being a standard 1 V / Octave VCO, but having a linear proportion between CV and frequency.

We noticed VCO's can be arse-kickin simple. A battery, a resistor, a capacitor and a 'four-layer-diode' (sorry i do not know the proper english word, but it's such a diode that starts conducting at a certain (positive) voltage (NOT being almost 0)) can already make a SAW Oscilator.

So, questions:

1) Why are most VCO's (e.g. in tom's cookbook) having a quite complicated structure. Just to make it 1 V/Oct? (than that must be hard.)

2) A bit the same question: Are there any circuits converting a CV linear with frequency to a CV linear to note (1V/oct)? Or do 1V/Oct need to generate the waveshapes in a completely different way in order to be so?

thank you!

Your blockrocking' Bee,

-- Peter van Hamersveld, plons at gmx.co.uk on 06-03-2001