You should really check out this video link below,
its great at explaining often misunderstood concepts behind digital audio and how things really work.
http://xiph.org/video/vid2.shtml
 

xiph.org
Demonstrations of sampling, quantization, bit-depth, and dither explore digital audio behavior on real audio equipment using both modern digital analysis and vintage analog bench equipment... just in case we can't trust those newfangled digital gizmos. You can also download the source code for each demo and try it all for yourself!

 
 
 
 

Thanks for the input everyone. I think I'll go with 24bits for the audio driver bit depth and 32bits for the rendering side. The 64bit engine appears from your feedback to be unnecessary, however it also seems that there is no down-side to leaving it on.
Thanks
PS Interesting video link, TheSteven, cheers...now if only someone can explain the explanations given.

Fabio Rubato
PS Interesting video link, TheSteven, cheers...now if only someone can explain the explanations given.

I haven't seen the video.  But you may find the explanation you're looking in a tutorial I recently wrote on this subject.  Read it here:
 
http://www.soundbytesmag.net/ofdigitalbitsanddecibels/

TheSteven
You should really check out this video link below,
its great at explaining often misunderstood concepts behind digital audio and how things really work.
http://xiph.org/video/vid2.shtml

 
 I enjoyed the video. Thanks!

gswitz

TheSteven
You should really check out this video link below,
its great at explaining often misunderstood concepts behind digital audio and how things really work.
http://xiph.org/video/vid2.shtml

 
 I enjoyed the video. Thanks!

I really like the how he clearly explains things and doesn't drown you in math demonstrating the points.

The 64 bit engine is for processing.  It doesnt' produce 64 bit files.  And with the speed of today's processors it doesn't slow things up.  
 
that and the rest of your settings is pretty much mine, so I think they are marvey poo-poo.
 
@

Thanks for the advice and brain drain links guys. I certainly aim to achieve 'marvey poo-poo' settings for my little studio. Just got a Quad-Capture to try it out as my Creative Elite Pro seemed to be the on-going cause of BSOD over the years. Working fine...now about a D-A convertor?? 

re >D-A convertor?? 
You've got a Quad-Capture, you've got Sonar - you should be fine.
If your mixes end up lacking its not going to be because you neglected to buy Brand X's D-A converter.
I'd save my money. If its burning a hole in your pocket buy yourself a some quality microphones.
 
For acoustic instruments proper recording & mic'ing techniques make a bigger difference than any element in the signal chain.

I have a good mic, but it's more about - for me at least - chasing a better detailed mix. When I read about how D-A converters improve upon this by using better converters and liking it to 'taking a blanket' off the speakers, then it makes me wonder about what I'm actually not hearing in mixes. It's another topic and I have a lot to learn. I suppose I'm chasing the fantastic mix which impresses me or makes me go 'wow'! 
 
I know at least that getting good mixes is a combination of having the gear, the knowledge and a creative application...and yes, whilst money is definitely not burning a hole in my pocket, I can look around to see what more might assist me in my journey to the 'perfect mix'. These forums and contributors are a great place to start 'throwing it all out there'.
 
Thanks for your advice.

Your Quad Capture has D/A converters too, that's how you get sound. A large part of the sound of D/A converters is actually the clock, getting a different D/A converter to hook up to your Quad Capture makes very little sense if it has to follow your QC's clock. And if you get one with its own clock you're basically talking about a new soundcard. While it is true that you could probably improve on things by upgrading to an RME card or something in that range, you'd most likely get a vastly greater improvement by spending the same amount of money on room treatment, monitors, good plugins or books/courses on mixing. Forget D/A converters for now. They may be worth your money at some point but it'll be a long time before they're the weakest point in your setup.