How much impact will adding a A/D converter to my studio add versus using the converters in my Delta 1010? I probably know the answer to this already, but will it be a significant improvement or more subtle? What will I notice.
Also, the 1010 has a SPDIF input and not the AES/EBU, any difference in sound quality between the two? I believe SPDIF can only go to 48kHz instead of 96 kHz, which does not bother me at this time since I record at 24/44.1.
I am thinking about adding the Lucid A/D 9624, because of price. I would love to have either the new Benchmark or Mytek units, that should be out shortly, but they are going to be quite a bit more than what I can buy a used Lucid for.
Like all things in your entire signal path, it is a question of the weakest link. Depending on your signal path and monitoring, you might not notice any if very little difference. I'd be willing to bet that you would find much greater improvement with having a very good to great mic and/or mic pre than new converters. It is not that converters are not important or won't help, but I always suggest that you start and the beginning of the chain and work your way out.
Per my post on additional mic pres, I have some good microphones, a good pre (Langevin DVC which I may sell to get the 4 channels of pre I need) and decent monitors (NHT A10). Once I get the preamp situation figured out, I figured the converters would be the next thing to add, if they will make a noticeable difference.