I side with Mech and others on this. A relatively inexpensive audio card can produce unhealthy ultrasonic garbage, whether during clipping or simply as a byproduct of a poor digital filter. It can further cause oscillation or instability in wide-bandwidth amplification stages, like many ss electronics. Whether additional equipment instability occurs or not, this ultrasonic junk will slowly cook your tweeter and/or high-pass x-over components.
Also, don't assume that because a circuit uses tubes that it is limited enough in bandwidth to help in your situation. A good tube pre-amp or buffer stage can easily be flat to 30kHz, and some much higher. If the problem is with sample rate spiking or distortion products within its passband, they will easily be passed downstream to the next component. Mech's suggested solution is sounding better and better. Good luck.
Also, don't assume that because a circuit uses tubes that it is limited enough in bandwidth to help in your situation. A good tube pre-amp or buffer stage can easily be flat to 30kHz, and some much higher. If the problem is with sample rate spiking or distortion products within its passband, they will easily be passed downstream to the next component. Mech's suggested solution is sounding better and better. Good luck.