I tested this for a couple of hours on a short vocal clip.
 
Major clip gain changes within each word, and also with/without track automation in a similar manner to see if cumulative effect had anything to do with it.
 
I also tried fast and slow curve for the nodes. This could in some circumstances make a tiny little zip in there on either fast or slow.
 
But when I really could make it zip - offset mode and drag fader on track rather fast - which I don't know if that is nothing but normal. As long as not persistent each play through, it does not matter to me.
 
Yes, I think samples from your export would be helpful, to hear exactly to which degree it zips?
You mean like tiny wobbles in tone, or similar?
 
If one gets a clear zip in an own project, one can change fade settings like dezip above.
My theory is that default values are not perfect for every operation - and a certain steepness would cause the fade ins to be audible. Since settings for fade ins are fixed value to use for any steepness, I mean, seems likely that there are conditions where fade ins are too slow or fast.

Finally got back around to this. Let's see if I can add this video:
 
<iframe src="https://player.vimeo.com/video/128682833" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> <p><a href="https://vimeo.com/128682833">clip gain</a> from <a href="https://vimeo.com/user17995442">John Tatlock</a> on <a href="https://vimeo.com">Vimeo</a>.</p>

Right, that didn't work.
 
https://vimeo.com/128682833

OK, if you watch that you'll have to listen carefully for the problem. But note how there are little clicks when the now time hits the clip gain nodes.
 
Things this is not:
 
- it's not to do with the steepness of the envelope; this now happens however far apart the nodes are
- it's not how it's always worked; I've been using this method in Sonar for years, and this is strictly a post Sonar 2015 problem
- it's not to do with any effects downstream; effects are in global bypass for this video.
 

I used to get a "zipper" noise when tweaking simple parameters in the PC like on the QuadCurve or other stuff. It was a system resource thing. I was still using my Layla3g through bridged PCI and hadn't yet learned about buffers. I got my new interface and all that went away but even with the old Layla just upping my buffers before doing mixing stuff made it stop.
 
Not saying that's the problem but if you've got your buffers set for low latency recording try upping them to see if that helps... just for the sake of troubleshooting.
 
Also... is this project specific? Sorry if you already answered that.

loopty loop

No, it never used to happen at all, and now it happens on all projects. Have latency settings fairly high; haven't changed them for a couple of years, in fact. I do all my monitoring direct, so I don't really need low latency.

I'm wondering if anyone can replicate it.
 

John T
No, it never used to happen at all, and now it happens on all projects. Have latency settings fairly high; haven't changed them for a couple of years, in fact. I do all my monitoring direct, so I don't really need low latency.

Perhaps S15 is just a little more resource hungry than its predecessors so it just barely nudged your system over the quirk point.
 
But I'll defer to the others knowledge. I've only really experienced that noise in that scenario or when using extreme settings on some plugs.

It's nothing like that; it appears in non-real time renders of the track, appears in bounces. It's something that clip gain is definitely doing.