> You talk about 'missing something....' about closed and open gates this is a question I have, How do you close and open a 'gate' I imagine it is similar to an on-off switch (electronically) I was told that it is the same as CV but somehow that does not ring true to me. Surely CV is a change of voltage brought about by differing keys on the key board. the +or - 1v .

Right, so as far as I understand it, everything you can do in a modular synth involves hooking up outputs to inputs, with a voltage that can be anything between -12v and +12v, usually even less than that (0v to +5v seems quite common).

When you play a note on a MIDI keyboard and send that to the converter, it makes a few different voltages symbolising different things. The gate goes up to +5v and stays there for as long as you keep the key pressed, then goes back down to 0v when you let go again. It's there to tell things (such as an ADSR envelope generator) how long the note lasts, and nothing else.

Another kind of voltage it sends is the pitch of the note. I explain this in more detail here: http://bytenoise.co.uk/Pitch_control_voltages

Bear in mind that with modular synths, you see a lot of what's going on behind the scenes or under the hood compared to hardwired synthesisers. For example, the oscillators keep oscillating even when you're not playing a note. The only reason you can't hear them constantly are because of the VCA. You wouldn't know that from using hardwired synthesisers, but it's pretty simple to discover (possibly by mistake, even) with a modular setup. Nothing's shielded from you, or rather, you're not shielded from the intricate workings of your machine.

The phrase "CV" just means control voltage, and is a catch-all term for whenever you're using the voltage of something to send information from one module to another. It's a somewhat arbitrary distinction though. Gates are sometimes called CV, as they do send a voltage out in order to convey information, but it's either on or off, there's no full range (it's digital/binary/boolean, not analogue, with intermediate voltages). So when you hear about "CV and gate", it's being emphasised that gate doesn't "really" count as CV, as opposed to the pitch. Try not to worry about the wording, it's a bit inconsistent sometimes. What's important is that the modules talk to each other using voltages.

And even the audio is voltages, and you can use audio as if it was CV, which is how FM synthesis works, by feeding one oscillator's output into another's input.

So anyway, yes, a gate is very much just an on-off switch, and in practical terms, you simply press a note on your keyboard, and the MIDI to CV converter tells the envelope generators this using a gate signal.

Those Sound On Sound articles probably explain it better than me, though!

All the best,
Zoë.