[edit: i forgot to mention something..]
Well it appears that the card is stable after replacing the 1000uF/16v NP by a 220uF/6.3v NP. I have since not been able to replicate the problem. [i know.. i'm not sure either if 6.3v is safe, but they dont have 16v220uF NPs and I think it's 5v only, but dont assume thats safe, it was more to try out the concept, as its most opposite to the huge beast i had there]
I will not pretend to know the exact cause - but it would appear the capacitor was involved (and even that I cant be fully sure of but I'll spare the details..). I would have to put the old one back up and re-test to be 100% sure, but I dont know if I'm much inclined for the moment
maybe in the name of pseudoscience
but not right now, enough excitement for one day.
About the constant nature of physics: yes in theory thats true, in reality some people have problems with their XFi while others don't (whether they are modified or not) - the instable nature of these cards makes it possible that some things cause problems on one system and not the next.
Also remember that until yesterday I only raved about this mod because I didn't realize something was seriously wrong until I started to swap cables.
According to the guys at groef (sorry if i seem to suck up to them but they are some of the most knowledgable people available on this subject) a too high capacity can overload the power supply circuit of the soundcard and over time cause damage, although they were more suspect of 1) the opamp swap and 2) the high faulty charge thats on our local tv/internet cabling here. I did route the tv/internet cabling through a belkin power cleaning thingy before i changed the cap, but it did not solve the problem, replacing the cap did.
So whats the conclusion of all this? None yet.. Except to be on the lookout for any problems and report them so we can establish the stability of this mod and if needed optimize it. Cotdt: there were a few others who reported problems aswell, if it was only me I wouldn't have put the cause at the modification, but since a few more reported after I posted a question about it, I decided to play open cards so people know what they get into
Not trying to question your knowledge on mods or this mod specifically, I still think its a great mod and the people from Groef were very interested aswell when I mentioned which opamp I had put on there. They also tried to explain the sonic relevance and disabling of the tiny 'tor' ic's, but it was above my head
are you familiar with them?