Marian has recently updated their Seraph sound cards. By default, they now have a slightly flatter frequency response, but that comes at a cost in phase response. When testing the new cards we found that we got up to 10% overshoots in our MPX signal.
We have contacted Marian about this and they have created a new driver that has a setting to get the old/normal behavior back. So, if you have an MKII card, please perform the following steps:
- Install the latest driver version, v4.3.4.0
- Go to Settings -> DAC, and choose "Linear Phase, Slow Roll-Off"
- Make sure to press Apply to confirm your selection, otherwise it will be lost after a reboot.
We will add a setting in Stereo Tool soon to make the response completely flat (with these settings you loose about 0.3 dB at 57 kHz, similar to what the MKI cards had - since we know that the filter is phase linear we can easily compensate for it, so look out for a "Seraph MKII" checkbox in the near future).