Buffers in playback queue is different from buffer size. Set it back to 2 and see (hear) what happens.

Thank you, Greg, I did set my playback queue back to 2, though it did not change things. It was on this setting (of 2) originally.
Thanks to Noynekker for the specific rec's on my sound card. Though it didn't work when I set the output source to "mixer," (I couldn't get any sound at all), I did try several other things, including changing the db settings. Again, no change
I even went to the M-Audio site. Lots of views to my question, though no replies in several days. However, I did see some other questions about popping. I tried a bunch of those solutions, even going into "bios," but again no change.
I"m starting to think that I may have to buy a new sound card just to get better support from the actual company. I think I've read that they don't support the Delta 66 anymore.
The one thing I haven't done was to change the slot of my PCI sound card. I'm not even sure there is another slot that can accommodate this long card, but I'll look when I get another chance in 2 days.
One other thing I found on some info on the M-Audio pages: My sound card is currently assigned an IRQ setting of 22. They say that everything above about 16 is actually a "virtual IRQ" setting, which mean it shares IRQ data with lower IRQ settings. I  think they said the way I can tell what is sharing with what is by looking at the motherboard documentation, or something like that. This is way above my pay grade!
Lastly, I was wondering if anyone specializes in this, and could spend time with me on the phone--for a fee, of course. It would probably cost a lot less than buying a new card. I do have a feeling that there is a solution, but I don't have a good enough understanding of all the components to attack this effectively.
Again, thanks for all your interest and support. 
LNovik
 
 
 
 

@LNovik, 
 
Let's back up a second, and get a handle on how things sound on what should be a reasonable set of settings:
 
Try: interface - Sample Rate 44.1 k or 48 k, ASIO Buffer Size of 128 
Sonar: Sample Rate of 44.1 k or 48 k (must match interface).  Record Bit Depth of 24 bits.
 
Try for a Total Roundtrip Latency in Sonar of about 10 milliseconds or a little less.
 
The above are reasonable for tracking/recording.
 
Also, make sure effects and such are not present, for purposes of testing.
 
And, you might want to make your playback and record MIDI buffers set to 500 instead of 250.
 
Lastly, is there any listed Firm Ware version for your audio interface?
 
Bob Bone
 
 

Just a thought as I used to get intermittent popping once over, then some helpful soul suggested disabling the Marvell disk controller in device manager. This fixed the issue for me.

OK: first, quickly to biodiode: turning something off in Device manager sounded hopeful, since, as I have said, I already have an IRQ assigned to my sound card that apparently is shared with other application(s). However, I couldn't find anything called the Marvell disk controller, or any disk controller in device manager. Any any thoughts on what I could, at least, temporarily disable in device manager might be helpful.
 
Thank you, Bob Bone, for those specific rec's. (where rec = recommendations, not record)
Just to be clear: on the first part: Try: interface - Sample Rate 44.1 k or 48 k, ASIO Buffer Size of 128 
I did this, except that on the Soundcard module it says: ASIO/WDM Buffer size of 128. It had been higher, so I turned it down. HOwever, I did not change to ASIO (though I was using ASIO when I began to have this problem.)
I guess I could try tomorrow to change back again to ASIO, if that is what you were suggesting.
2)I did the next few steps on Sonar, though the lowest I could get on roundtrip latency was around 11 msec. I assumed that was fine.
3)Interestingly, when I got to the last part about increasing the playback and record MIDI buffers to about 500, that is something that was rec'ed a while ago. However, I was never able to increase the record buffers, which I had reported. However, what I found was that if I unchecked the "enable write caching" box just above this option, I was then able to increase the record buffer from 256 to 512.
Now, for the interesting part. I then recorded my approx 16 measure saxophone MIDI patch to audio. The first 2 times I listened to it, I did not hearing ANY popping. THis is better than I had done in the past week or 3. However, when again listening to the same passage, I would then hear the same popping as before scattered thru this short recording. I must say that in the places it occurred, it was just as bad as before, with 10 or 15 crackling sounds at a time. However, out of the 10 times I listened, there were still least about 4 times that were devoid of any significant amount of extraneous sounds. I guess I could try tomorrow with 1000 or 1024 buffers in the playback and record, if you think that would be practical.
Thanks again for your interest, time, and specific suggestions.
Larry 

already have an IRQ assigned to my sound card that apparently is shared with other application(s).

Try and put your sound card on its own, so its not shared. But reading all your posting, you have a 95% chance its your sound card and 5% chance its an IRQ conflict.
 
If I was you, I would get a new soundcard and stop wasting precious time and just be done with it.
 
CJ

Ah!, life is so complicated. Thanks for your response, CJ. On the first point, I would of course try to change the IRQ setting if I could However, after looking up some tutorials on IRQ's, it said that I can't really do that. All I can do is find out what is competing with it, and try to disable it. As I had said, they said that an answer might be found on the Motherboard Documentation file, though I have know idea where to look for that.
 
RE: the 2nd suggestion--just buying another freaken card--I must admit it becomes like a mystery or puzzle to be solved, so it's been an interesting process. However, I agree that it's taking a lot of my time--and that of many other generous forum contributors such as  yourself. In fact, earlier in this thread, I had asked for some suggestions for a new card. Thus, while it takes a lot of time to try to fix this old card, it would potentially take me hours to do the research to discover what new card to get. 
 
Thus, if you or anyone has a suggestion for a good card, I'd appreciate it. I'm not even sure if it needs to be a PCI card that fits into a slot, or a box. I do have a MIDI interface already. It's  kind of old--but it seems to be working OK. I'll post my setup again below. I don't need mic inputs into the card, since I do all of that with my mixer.
 
Thanks again for the suggestions.
Larry N
 
 

OH yes, my specs:
Sonar Producer 8.5, M-Audio Delta 66, Midisport 4x4, Intel i5 650 @ 3.2 gHz, 6.0GB RAM, 64 Bit OS. Mackie 14 channel mixer; various synths

Just to follow up. I did end up buying the Focusrite 2i2 card. Though I still have some problem with connectivity with this device, when I do get it to work, I NO LONGER HEAR the Rice Crispee sounds of Crackles and Pops. My only problem is that my unit doesn't work when I turn on the computer. I have to manually remove the USB device from the computer, and then re-plug it in. It then works fine. I have a querry into the Focusrite support about this.
Thanks for all your input and support.
LNovik

This shouldn't fix this particular problem, but something you might want to consider anyway - in Power Management's advanced options, there is a setting under USB Settings, called something like Selective Suspend - you want that turned off.
 
By default, Windows will deactivate USB devices after some period of idle time, Sonar will then lose access to it.  I always make sure to turn that setting off.
 
Wish I understood why your device would start up not seen by Windows - sorry - hope the above helps, in general.
 
Bob Bone