Is this me or a bug? Loading disabled effects rack wrecks audio!

Question

Background:
I am NOT an audio pro, but am an experienced tech guy and have used Adobe suite products for many years.
Just loaded up CS6, including all updates, on a new decked-out Win7 computer (32G RAM, 12 core CPU, CUDA board, etc).
I have a clip (96hHz 32 bit) I'm using to learn the workflow I will use for analog->digital conversion...
There is a musical section in the middle that sounds truly awful with my effects rack in place. But then I noticed I could not get back to the original...
Symptom
If I load the audio clip, all is well --  plays as expected.
If I load my Effects Rack, with all effects preset to be disabled, the sound is immediately and obviously messed up.
Turning the effects on/off does not fix the problem.
Questions
- Is there any reason a set of disabled effects might still impact the audio? If so, where do I find such settings?
- Is this a likely bug?
- Anyone else ever encountered anything like this?
Thanks much!
Pete

Answer 1

NAILED IT.
The following is 100% repeatable for me. Can anyone else replicate this?
1) Choose 10-20 seconds of music, with a bit of silence before or after (as an audible marker), stereo, 32 bit, 96k -- or even 44.1k although the problem is not as pronounced in 44.1k (see below)
2) set up to play as a loop
3) load any of the following into your effects rack. Loading more than one just makes it more obvious.
  a) Adaptive Noise Reduction, default settings, then turn ON high quality and set FFT size to 16384. (8192 is sufficient for 96k, but at 44.1k I need 16384) [This one produces horrifyingly awful results]
  b) Auto Click Removal, default settings, then Threshold 1, Complexity 100 (This one only causes trouble on 96k files)
  c) Auto Phase Correction, default settings, then Analysis Size 4k, Time Resolution 1.0 msec, Response Ultra Slow
4) BE SURE the effect is turned OFF (but leave the rack on)... or turn the whole rack off. The effect SHOULD do nothing at all.
Now play the loop a few times.
Notice the following anomalies:
A) The cursor tracks (sometimes jumpily) in real time, but the sound is much slower. With Adaptive Noise Reduction @ FFT=16384, I can't really tell it is music... running about 1/10 speed or something
B) It is as if the on/off switch for the effect does nothing to disable the effect during playback
C) Your CPU will likely be idling. Whatever is slowing this down is NOT a bunch of processing, but some other kind of overhead/bug
D) In some situations, I even see the Levels Meter stop moving, as if there weren't enough spare cycles to update it.
Discussion
I wonder how many effects are "always active" like this during playback? Right now, I feel I cannot trust this engine to give me reliable feedback for my settings. My suspicion: most if not all effects are at least partly active for playback, even if turned off, at least with respect to the underlying engine.
It is claimed some of these effects can have performance issues depending on the platform. My platform has far more capacity and speed than required, yet still there are issues. This tells me I cannot trust my ears to tell me if a particular effect and setting is giving me poor results... or if it is just this hidden engine bug causing the sound to degrade. (Note: if I use all three effects with settings as shown, my CPU is running at 11 percent. Not even enough to get the fan going! Definitely not system-limited.)
If there IS some kind of built-in engine limitation relating to these kinds of problems, I highly recommend that Adobe implement a visual marker to indicate that the effects rack is unable to do its thing in real-time, thus what I am hearing is not an accurate representation of the effects. (However, even if so, I would expect that disabled-effects should not contribute to any performance problem.)
I sure hope this is enough so others can replicate the problem!
Thanks much,
Pete