Thanks for checking this out Danny.
 
Here's a recipe that seems to show the problem most of the time on my system using what I think are stock plugs with any UAD system:
 
Start a blank project
Add one audio track, add one bus as an aux send from the audio track, and put some audio in the track.
Add Realverb to the aux send, hit play to hear the beautiful room-like ambience it provides.
Put a legacy 1176 plugin in the track fx bin, hit play.
Copy the 1176 to the second slot in the fx bin, hit play.
If necessary, copy the 1176 again, hit play.
 
What I am seeing is that the Realverb stops processing the sound (but still passes audio, and it's phasey so I think it is not latency-compensated) after one to three 1176 instances.  It doesn't happen with every instance, but it eventually happens every time I test it.
 
The same thing happens with current UAD effects.  Copying the 1176 is just a convenience, the same error happens with new instances.
 
This doesn't happen in Cubase (which has some big differences in the audio engine from Sonar) or Samplitude (whose audio engine is relatively more similar to Sonar's, I think).
 
If you don't see any problems from this, I may have to come back with my hat in my hands, and then eat it...  I can't think of what could be amiss with my system though..

Lookin at the UAD System Info panel, I see that whenever the reverb stops passing audio (ie when it gets problematically disabled), it is actually unloaded from the UAD card.  It looks like there may be some reshuffling of plugins between the cards, and the verb is getting lost in the shuffle, somehow.
 
Edit - disabling one of the cards doesn't fix the issue, so it's not from reshuffling.  Also, DSP LoadLock and Extra Buffering settings have no effect on the issue.

Looking at the UAD System Info panel while testing the same scenario in Cubase, the plugins are not being shuffled between the cards each time I add an 1176.  So, my theory is that whatever Sonar is doing which is causing the plugins to be "reshuffled" is also causing the UAD system to believe that the reverb on the aux send is to be unloaded.
 
Later today I'll see if there are any settings in Sonar that affect this, but for the moment it still looks like there's something broken in the relationship between Sonar and UAD...

Brian, I just got in....massive snow in my area which is why I didn't get back to you sooner. Give me a few hours to get myself together here and then I'll run some tests and I'll get back to you. My initial thoughts are....the UAD 1 type plugs have always given me a few issues in the later versions of Sonar. (X2 ans X3) The 1176 being one of them...which is built on older technology. So I'm wondering if that may not have something to do with it...as well as the verbs. I'm going to try the tests using your steps then I'm going to replace the verb with the EMT 250 and see if it does anything. I'll be in touch..
 
-Danny

brian brock
Thanks for checking this out Danny.
 
Here's a recipe that seems to show the problem most of the time on my system using what I think are stock plugs with any UAD system:
 
Start a blank project
Add one audio track, add one bus as an aux send from the audio track, and put some audio in the track.
Add Realverb to the aux send, hit play to hear the beautiful room-like ambience it provides.
Put a legacy 1176 plugin in the track fx bin, hit play.
Copy the 1176 to the second slot in the fx bin, hit play.
If necessary, copy the 1176 again, hit play.
 
What I am seeing is that the Realverb stops processing the sound (but still passes audio, and it's phasey so I think it is not latency-compensated) after one to three 1176 instances.  It doesn't happen with every instance, but it eventually happens every time I test it.
 
The same thing happens with current UAD effects.  Copying the 1176 is just a convenience, the same error happens with new instances.
 
This doesn't happen in Cubase (which has some big differences in the audio engine from Sonar) or Samplitude (whose audio engine is relatively similar, I think).
 
If you don't see any problems from this, I may have to come back with my hat in my hands, and then eat it...  I can't think of what could be amiss with my system though..

Hi Brian,
FWIW, I just followed your recipe and duplicated your behavior after inserting the very first instance of the legacy 1176. The RealVerb plug stopped processing audio and I got phasing. The phasing looks like it's due to signal being present on the aux bus (where the RealVerb plugin is) and PDC still functioning but since the plug isn't doing anything, in terms of both applying reverb AND inducing delay, the signal on the bus is delayed. This results in two slightly out of sync copies of the audio (one on the track and one on the bus) and thus phasing.
 
Just for kicks I removed the 1176 Legacy from the track, disabled and re-enabled the RealVerb plug to make it work again and then added an instance of the new 1176 Rev A to the track. The symptoms came back immediately, so it's not just the Legacy 1176 that's causing a problem.
 
Something is definitely not working here....
 
Dean

yeah it happens with current UAD effects (such as the 224 reverb and the mkII 1176)  too - I just used the classics so that it would be easy to reproduce.
 
glad to hear I'm not the only one encountering this.

more information -
 
when trying the same thing with the Moog filter instead of the reverb, the Moog also gets disabled, but when re-enabling it I get a message from UAD saying that "the Extra Buffering setting must be enabled when using this host".  This is of course, when Extra Buffering is disabled.  So it strikes me that this could all have something to do with Extra Buffering.

CakeAlexS
 
Here is another idea...
 
X3 -> Edit -> Preferences -> Audio -> Playback and recording -> Turn off "Always stream audio through FX".

 
and we have a winner!
 
Turning off "Always stream audio through FX" makes the problem go away.

Interestingly, the UAD system info still shows the plugins being "reshuffled" when the 1176 is added, and shows one too few plugins in total (the aux send effect being the missing one).  Then when I hit play, the reverb turns back up in System Info again.

needless to say, I prefer to enable "Stream audio through FX". 
 
Cubase has no problem allowing UAD reverb tails to play out...
 
I'd love to hear more reports about this.
 
 
 
I have changed the thread title and added the workaround to the first post.