Cherry Audio Forums

I am very new to modular synths but I was following the tutorial from Venus Theory here: https://www.youtube.com/watch?v=jk7cJ3EmrCs

I have exactly the setup but when I click a note on my midi keyboard, it plays a sound, but it never stops. It will play a new note, but it doesn't stop playing something. This is different from what he is showing and I am not sure what I am doing wrong.

You should post an image of your patch. There can be a few reasons for the problem.

Absolutely... I used to be a support engineer, I should know better



I was going to attach a video but the forum doesn't allow for it. I can host it if needed. Let me know.

also:

• Windows 11

• Audio is a Presonus Audiobox 96 USB (ASIO), but I also tried it on Windows Audio with same result

• Ryzen 7 2700x, 16gb RAM, Radeon RX580

On the Amplifier module turn down the GAIN knob to its minimum setting.

This seems to trip lots of people up. The knob should be labelled DEPTH and work in the opposite direction then it wouldn't be so confusing.

Awesome... thanks so much for this response. It is indeed working as expected now. I need to review the tutorial as I am almost certain the gain was turned up by instruction there.
Anyway, thanks again for the help. Much appreciated.

ColinP wrote: ↑Mon Apr 18, 2022 1:41 pm On the Amplifier module turn down the GAIN knob to its minimum setting.

This seems to trip lots of people up. The knob should be labelled DEPTH and work in the opposite direction then it wouldn't be so confusing.

Thanks colin p. this was driving me nuts too. The gain was at 2.0% and so looked off!

Tiny correction to a comment.

The GAIN knob is not depth. The CV AMOUNT knob is depth. The GAIN knob value is summed with the input control voltage (multiplied by the CV AMOUNT setting). On Moog modular VCAs, this knob is called INITIAL CONTROL VOLTAGE. To make things abundantly clear, here's a one line formula that describes the VCA action in LINEAR mode. EXPO mode is just a differently shaped response to the control voltage.

Output = AudioInput * (CVinput * CV_AMOUNT + GAIN)

So you can see that if GAIN is not zero, there will be constant leakage of the AudioInput to the Output. Sometimes this is desirable, especially when you are using a VCA for control voltage processing. Usually GAIN is set to zero when used in its traditional audio role. Since CVinput can be positive or negative, if GAIN is non-zero positive, the CV (if negative), can take it back down.

Clear as mud? I hope not.

--mb

Hi Mark,

I can see all that but labelling the "Initial CV" knob as GAIN obviously confuses many users.

I'd just use one knob called DEPTH and this formula...

output = input * ( cv * depth + 1 - depth )

With depth and cv in range [0,1].

So with depth at minimum: output = input.

With depth at maximum: output = input * cv.

With depth halfway: output = input * ( cv * 0.5 + 0.5 ).

This results in the kind of behaviour that users might intuitively expect and only requires the single knob.

if cv is allowed to be negative then this just inverts the polarity of the input as most users would expect too.

I think the main problem is that CV amount (the most used one) is a small knob, with bipolar action. Whereas Initial Gain (quite an unusual function to find on most hardware synths) is bigger, and placed 'centre stage'. If their positions (and relative sizes) were swapped, it might make it a little more intuitive.

Either that, or create a new 'VCA 101' which just has a uniploar CV attenuator (0-100% +ve only), and which defaults to 100% when you drag it into the rack.

Hell, I might throw that together myself and make it available for free in the VM store. That's if it hasn't already been done by another dev, of course.

https://youtu.be/jk7cJ3EmrCs?t=242

I don't think it needs complicated explanations. What the knob does is in the video.