SPDIF out to interface quality...

Follow your instincts , that is your workflow. Do what is more convenient, think about playing rather then getting lost in theory.
We are talking guitar amps here, not 0 to 200 kHz. Use S/P-dif if it is convenient for your setup. I routinely switch between digital and analogue and the difference is small. This is from someone that on the other side of the job takes these small things into account, each and every one of them....

You can go into Logic without worrying too much as long as you avoid clipping and then gain staging if you need lower levels. If I am not mistaken Logic is 32 float, not sure about the newest release so really no worries once you are in the digital domain. You may want to avoid clipping on the way out generally speaking as lesser converters can have problems reconstructing a clipped signal.

Any chance of the Kemp getting the option of 48K?? That's what I run my DAW at and would like to continue to do so...but also use the Kemp for re-amping through spdif. Wouldn't it be just a software upgrade?? Or not?

Yes, but it would ask for a higher hardware performance as well. We (well, I :)) can't say how much this would impact on the overall operational performance

Quote from Yorolpal

Any chance of the Kemp getting the option of 48K??

I wouldn't bet a single cent on this to happen. Maybe this would be something to be considered for a 2nd generation Profiler, but talking about the hardware we have, don't hold your breath.

I'm in the same dilemma and I solved this for now with Behringer UltraMatch Pro SRC 2496, although I certainly would prefer to live without the additional gear.

Cheers,
Martin

More than sample rates it is the fact that the KPA has to act as a master that bother me a bit instead of being able to lock it to the DAW clock (or converters) clock.
For the time being I just go analogue in through the AD.

Is there a Thread, where someone compares Analogue and SPIDF in Sound Quality? I'd like to hear it for myself.

It is more about your ears than other people's opinion. S/P-dif is a digital transfer hence there is no change, while going through two conversion stages (DA from the KPA, AD into your DAW) obviously involves a change. It is not a matter of "quality". A digital transfer is identical to the original unless something is broken or not properly implemented. An analogue transfer will always be dependent on converter quality.
To close this up we are talking about electric guitar amplifiers/sounds here so unless you are using an extremely cheap and old interface/soundcard the difference will not turn your sounds from gold into copper and vice versa. In other words no sleepless nights, enjoy the KPA and use what fits best your workflow. Make music!

Talking about sample rates, I just wanted to clear up that CK has said the Profiler EXPORTS at 44.1 but has different internal sample rates based on what it's actually doing. For the amp emulation, he said the sample rate gets much, much higher - something ridiculous like 300 kHZ. Converting from one sample rate to another obviously takes clock cycles, but it can occur at the very end of the chain. In other words, it would not require all the software to be reworked. I am not sure why the decision was made to only use 44.1 kHZ, but from my knowledge it doesn't seem too difficult to allow conversion to a different rate, provided the memory/processor power is available.