I asked HeadFi members who own the Fidelio X1 to rate and comment on the sound quality of the X1 when used with different DACs/amps, portable music players etc.
The results of the survey I conducted are shown here:
If you have not taken part in the survey and would like to add SQ ratings and/or comments of devices you have used with the X1, please PM me or write it in the above thread and I'll add it to the table. I am planning on updating this thread periodically so that it will serve as a reference for current and future owners of the X1.
Thanks to everyone who participated!