Quote Originally Posted by ultraviolet View Post
I tried a pulse transformer on PC spdif output to DAC earlier and I have to report that in my system it seemed to make absolutely no difference to the sound, which was a shame. Transformer was free though so not lost anything I guess.

Just waiting for new op amp to arrive to try out on DAC output now. If that doesn't make any difference to the sound then I shall have to assume my ears are broken.
Sorry to hear that. Does the card have an output TX already? How did you implement the cct? Did you remove the existing o/p cct? What tx did you use, they can be quite specific?