Benchmark dac and AntelopeAudio Isochrone OCX Digi

What is it you would hope to achieve by doing this? The Benchmark is largely jitter immune, reducing jitter to levels close to analyzer limits. See Stereophile's actual measurements, for what they are worth given the difficulty of measuring jitter.

But, what you're saying makes no sense. If jitter isn't a problem with the Benchmark (I have one), then it wouldn't do anything to "stabilize" the clock's timing. Stabilizing the clock's timing would, by your argument, reduce instability, increase clock precision, and reduce jitter. But, who has measured clock instability on the Benchmark? What is clock instability? Did you know the Benchmark deals with jitter by upsampling everything that comes in?

What is a $5K dac? Does an over priced and poorly engineered $5K dac sound better than a good $1K DAC? Remember, good audio engineering is no more expensive than bad, and the parts for any dac are less than $100.

In matched-level blind testing, your Benchmark is as good as anything, and better than many.