Quad operator Leaking VCAs


First of all I would like to congratulate the creator of this beast!
First thing I check on all my music equipment its the definition, power, and clarity of the low end. On this module there is plenty and can be sculpted with a lot of control and detail!

However, I noticed the on board vcas (gain) bleed even when patched.
Is this normal for the unit?


Hi Alex,

I traveling just now and cannot do explicit testing to refresh my memory, but I think I’d expect a little of this as implementation is now. It’s actually a virtual VCA applied in software so something can potentially be done to close better for non-zero but very low voltages (e.g., treat voltages below 50 mV as true 0). It’s something I’ll look into for a future firmware update.

Hey, thank you very much, closing them fully on future update would be great yeah!

I too am noticing this. What I love about the Quad is you don’t need to go through a VCA when patching as it has a built in digital VCA. However, it doesn’t fully close.

What is the progress on this (if any?)

Anybody?.. @bigwill

Sorry for the slow reply and missing your post a few weeks ago—it’s been a weird few weeks for me personally (travels then a long tropical illness as a follow up), haven’t had as much time to labor on Quad Operator stuff as I’d like. I also had to prioritize a fairly serious bug fix firmware (which I prefer not to commingle with performance improvements like this or new features for the sake of sanity should the need to further debug issues arise). But I haven’t forgotten, and I’ll try to find the time soon!

Thanks for the reply. Sorry to hear about your mishaps. Hope things are getting better.


Possible to have a word on the leaking VCAs please?



First, apologies to you toumpouris. The Discourse software is supposed to notify me by email of unread responses, which it appears not to do consistently. I missed your message in January, and the volume here is so low I don’t check it often enough.

After some delayed through early part of this year, I’ve found the time to work on this and some other issues. I have a fix now in the code, which will be released soon.


Thanks for your time, looking forward to the update!


Thanks for your patience! Here’s the update. It addresses the leakiness by being full closed for any gain CV below ~50 mV. Let me know how it works out for you!


Lovely, will update asap and let you know!


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