@zoom25 Thanks for the interesting link about jitter, will make some time to check it out. When you used a longer length of same cable and connectors you said it sounded more relaxed. I've been thinking about that, not sure if that was good or bad. Did you mean a lack of soundstage and/or detail.
As you increase the length of the AES cable (same wire + connector), the sound does get more laid back and starts to loose a bit of focus. The soundstage also gets a bit larger and diffuse with the larger cable. This was not a problem with something like the HD 800 w/out modifications or EQ as their soundstage was already big and only got bigger, plus it helped remove some of that bite. The image getting a bit diffuse was only not that bad on the HD 800 as they already imaged so well.
However, when you have neutralish speakers and headphones, with the ability to utilize EQ to get the most balanced sound, the shorter cables are my preferred choice. I use the BDP-1 with Roon. Within Roon I use the preset for LCD-2C. If the rest of the chain is balanced and there is nothing you are trying to cover up, the shorter digital cables will give you the most locked in image and clearest details. The difference in texture and sharpness of transients and things like bass attack and decay is better on the shorter cable.
In a way, digital cable length can be used as a litmus test. If the shorter digital cable produces undesirable results, it may not be the cable that's creating something nasty, but simply better revealing a problem that was previously hidden. Of course, it is possible you could use a longer digital cable to cover it up, but the much better decision in the long run would be to fix the true source of the problem and stick with the shortest digital cable that will give you the least jitter.
When I had the HD 800 for 2+ years, I flip flopped between longer and shorter cables. However, with the more balanced and non-fatiguing Audeze headphones, I have always preferred the shorter 2 feet TPR over the longer 3173 (10 and 18 feet).
Since I have been talking about length so much, it's only a matter of time until somebody posts this or brings it up:
https://positive-feedback.com/Issue14/spdif.htmPro Audio LA makes these cables at roughly $20-$30. One could easily get made multiple AES and SPDIF cables from there and at various lengths, for the same price as a single cable from a boutique manufacturer. If you buy from an 'audiophile,' you are stuck. There is no room for personal investigation unless you are made up of money.
If you keep your BDP's stacked or very close to the DAC, go buy a 1-2 feet AES cable from a reputable manufacturer with Neutrik connectors. If you are stacking, you can even get something like a 6 inch made. I remember reading that James has a 4 inch for his BDA+BDP stack. It would be cool if Bryston also made shorter jumper versions for use specifically with their own Bryston gear when stacked for best digital transmission.