Hi Folks,
I have an M-Audio Delta 66 in use with Sonar Pro on Windows 10. Input and output work with its channels 3 & 4, but on playback there are clicks and pops. I can change a few things here (see image), but shouldn't need to.
 
Because this interface is so old, and it doesn't even technically have support or drivers made for Windows 10, I'll replace it if I need to, just wondering if there are things I can try before giving up on it.
 
Thanks,
Ben

 Ahh . . . your screenshot brings back great memories.
I ran the Delta 66 for 10+ years, what a great interface. When Windows 10 came along, I saw the writing on the wall. I used it with Windows 10 for a short time, and started to have lot of problems . . . and with no more updated drivers ever going to be written for it, I spent a couple hundred bucks on another M-Audio device.
 
Basically, it worked with very simple projects . . . but when pushed a bit, it would easily fall over.
I mostly recall the "motorboating" . . . when the interface totally freaks out, and you have to dive across the room for the volume slider, to save what's left of your $1000 near field monitors.
 
My advice, just spend the couple hundred bucks. 

It should work fine, previously all my systems had Delta 1010's, I still have one system running a Delta 1010 with the 6.0.8 driver, (it's the same for the 44' and 66's) It worked fine with Windows 10, and still does, I ran everything at 128. Something you can try, if you have another DAW, run exactly the same project, same amount of tracks and busses, same plugs etc, and see how it goes in the other DAW. If you don't have another DAW, download the demo of REAPER, it's exactly the same as the real thing, don't worry about the (subjective) hideous interface, it's just to test, just duplicate your SONAR project exactly (or as close as you can) and I bet there's a better than even chance that the problems you are encountering in SONAR are non existent in the other DAW. Then draw your own conclusions, there may be some settings in SONAR that you can mess with that will alleviate the problem like perhaps the playback I/O buffer size etc.
 
They are reasonably good cards, I loved (and still do) the 1010 and 44 prior to that, and as I said the 1010 runs fine under Windows 10 (same driver as 44 and 66), but they are old (not necessarily a bad thing), I only changed on my main machine for giggles and to 'modernize' a little, not because of any issues or anything, I could still be perfectly happy with the 1010, great sound and latency. Best of luck whatever you do.

Thanks all. I decided to get a new USB audio interface - mainly because troubleshooting gear interrupts the songwriting process and kills the muse.

Smart choice . . . old gear + new OS = aggravation
Get the new USB interface that includes both Audio and MIDI, so you can lose the Midisport 4X4 as well.
(I have one of those in my museum as well)
Hope you're back online with the creation process ASAP !