System: i5 laptop, 8gb, 250gb ssd (134gb free), win8.1 (fully patched & optimized for sound per KB instructions, networking off), Sonar Platinum, M-Audio Fast Track Pro
 
Problem: Audio engine randomly goes into full distortion, sometimes when I'm playing (anything - guitar with or without plugins, midi kb live or from midi, sometimes I'll walk away it's fine, come back it's distorting. Seemed to go from "occasionally" to "frequently" when I upgraded from X3 Producer to Platinum
 
Workaround: click the reset audio engine button off/on. Sometimes (like when I'm waiting to get a tech on the line so I can let him hear it) it'll just resolve itself, no intervention required.
 
Note 1: Today was the first that I had time to try to call tech support. Would've been nice if the phone robot had been told it was a holiday, instead of telling me over and over that the current wait time was 1 minute....
 
Note 2: This problem does NOT occur with Cantabile (VST Host) or Ableton Live.
 
I've sent this to tech support but, meanwhile, anybody got any ideas?
 
 

Is it distortion or dropouts? Each can sound like the other, but they're two different things with different sets of causes. Dropouts are more common, and the most likely cause of intermittent dropouts on a laptop is the wireless network adapter.

Many folks have had trouble with WiFi adapters/drivers, myself included, due to DPC latency spikes that cause all manner of glitches and interference with applications that do streaming audio - like Sonar.
 
This is pretty easy to test.  You could download and run LatencyMon and let it run for a few minutes without Sonar running, and it will tell you which applications are spiking DPC latency, if any.
 
Another way to test, and quicker, is to temporarily turn off or disable your laptop's WiFi right before you launch Sonar, then after finishing your Sonar session you can turn on or enable the WiFi again.  Super quick to do, and for lots of folks this gives instant happy, by getting rid of any WiFi DPC latency spikes.
 
On many laptops, there is either a physical switch or a function key present to turn off WiFi and if either is there that would be the simplest way to do it.
 
If there is no switch or function key for it, you can still do it, by going into Windows Device Manager, locating the WiFi adapter/drivers, and disable it (right-click on the WiFi device and click on disable).
 
To turn it back on or enable it, just reverse what you did to turn it off or disable it.  Soooooo, if you used a switch or function key to turn off, use the same thing to turn back on, or if you disabled the WiFi device in Device Manager, go back in to Device Manager and right-click on it and click Enable.
 
I would suggest you try the above and post back with an idea of whether or not that cleared it up for you.  If so, kewl.   If it did not help, then me and likely others will go into a deeper analysis of how things are set up on your system, etc...
 
The GOOD news is that your issues are not any kind of widespread 'show stopper' or you would see zillions of really unhappy folks.  This means that your issues are likely fixable. :)
 
Bob Bone
 

It's not unusual that Ableton Live would work. I don't know how you use Ableton Live, but I use loops and not linear tracks. Typically these are short enough they just get dumped into RAM and streamed from there. Many times I just put the project on a USB stick and stream off that to save system memory and hard drive access...can't do that with most programs.
 
However, I sure have seen a lot of posts with problems that reference "M-Audio Fast Track Pro." You might want to poke around the forum for threads about the problems people encountered, and how they dealt with those issues. Unfortunately I don't remember specifics. 
 
Meanwhile, try increasing the latency considerably to help determine is the problem is latency-related. If so, then we can start investigating ways to optimize performance so you can use lower-latency settings.

Bitflipper - it's distortion. Nasty, square-edged digital distortion
 
Robert e - disabled all network adapters, shut down every power management setting I could find, found some more online, shut those down, in advanced system settings set visual effects for best performance, set processor scheduling for background services. Only thing I can't do anything about is Intel Speedstep - no BIOS setting on my machine.
 
I ran the Latency monitor while running Sonar and playing guitar (straight in from my pod, no plugin) till it farted out. Nothing in the monitor to indicate anything special happening. No times anywhere near 1ms, so I'm thinking that the problem isn't latency.
 
Anderton  - The way I use both daws is basically as the world's biggest amp sim. Several plugins and a channel for my pod, coupla drum programs, synth, organ, piano. When I'm playing along and get inspired, then I might record - if I remember to push the button! So, really, this has nothing to do with actual recorded tracks. And, of course, Cantabile isn't really a daw, though it will make a stereo recording if desired.
The posts I found referencing Fast Track Pro problems were mostly old Sonar versions, old Windows versions, old drivers, and, of course, "my XXX interface has better preamps". My FTP works fine (and always has) everywhere but Sonar, especially this version, so I don't think it's the problem. While I can use 256 as a sample rate in the other programs (and plugins that have standalone versions), I have to use 512 in Sonar or I get crackling, dropouts, etc.
 
Going to dinner now....

OK, if it's "nasty, square-edged distortion" then you've got a plugin that's going bonkers.
 
The audio engine itself will not distort - ever. It's got a thousand decibels of headroom. However, that also means it can certainly drive your audio interface into distortion.
 
Next step is to determine if the distortion is occurring pre- or post-master bus. Next time it happens, mute the master bus but don't do anything else. Have a look at the track meters and see if one of them is pegged. If so, it's one of the plugins (or a virtual instrument) on that track. If they all look fine, look at your busses. Turn off your speakers and un-mute the master bus. A track or bus will probably be pegged in the red, and you should be able to selectively bypass plugins until you've identified the culprit.

If you are having to use that big of an ASIO Buffer Size for recording, than at least one of your plugins is jacking up your DPC latency - look for look ahead processing or using lots of CPU.
 
And Bitflipper hit on a good approach - look at each plugin one at a time until you find all the ones that cause this issue for you (could be more than one of them).
 
Bob Bone
 

Bitflipper - nope, nothing weird on any of the channels or busses. I listened to it for a bit thru headphones. It's weird, I can hear the guitar, and the drums, UNDER the distortion. Tomorrow I'm going to try a new project, just the one channel for guitar, take that from my pod, no (guitar or effects) plugins, and a channel for ezdrummer.

Hopefully, you'll get no distortion with your minimal-project experiment, because if you do then your audio interface is broken.

Undo this 

rd2rk
 set processor scheduling for background services

 
Not recommended by Cakewalk there is another thread about that going at the moment.
 
http://forum.cakewalk.com/FindPost/3184441