I want to send CV from four channels out of a Qubit Pulsar and have that CV trigger samples elsewhere. Can I run each CV through one of the VCAs and "mute" the CV?


Sure, if the VCA has mutes, I don't see why not.


As long as the VCA fully closes, you should be able to do what you want to do. There are small mute modules that may make this task simpler, but you can modulate VCAs for more interesting patches. Check out this video from mylarmelodies for some VCA ideas.


One note here: VCAs that are able to affect CV and modulation signals should be LINEAR and also DC-COUPLED. These are sort of workhorse VCAs in a build as you can use them for basic audio amplitude control AND CV/mod control. But these need to be linear because if you change a voltage by a given amount, that amount needs to reflect the CV scalar system. Case in point: let's say you want an LFO to sweep a VCO by a 5th on one sequencing point, but by an octave on others. With that, it's just a matter of calculating the voltage change needed, then sending that from the sequencer to the VCA. Easy-peasy.

Now, what EXPONENTIAL VCAs are about is 100% about audio. Since we perceive "apparent loudness" on an exponential scale (phons), we use exponential VCAs so that an incoming CV or mod signal can affect the thruputted audio on that same scale. Also, VCAs for audio usually are AC-coupled...they cannot pass voltages down in the subsonic and/or DC range. This is useful because DC + amplifier + speaker = And this is ALSO one reason why transformer-balanced output modules are also useful, because they block the same subsonic and DC signals.


Hi Lugia,

Ha, ha, every time I watch this video I still have to laugh. Brilliant clear demo what happens if you put DC to your speaker.

"So, you should put AC to your speaker, not DC", ha, ha, he keeps repeating that. Anyway the smoke should tell the rest ;-)

I am still grateful to you and some other members here on this forum telling me this, now almost 2 years ago. I don't save money on a good Audio Interface Input/Output module. I want to be able to sleep at night and knowing that the next day my speakers still work and the room has not this awful smokey smell from last night when DC "slipped through" to my speakers!

Thank you for demoing it again and kind regards, Garfield.

For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads