Just to add a bit to the input above: I have a Portal Panache, and a Berning Micro-Zotl. I don't use your cans, but a pair of Sony MD3000's. The difference between the two amps is not subtle, and though the Panache has a decent headphone section for an integrated amplifier, it just doesn't approach the smoothness and refinement of the Berning. Listening to the two A/B I do not want to listen to the Panache very long, and it doesn't take golden ears to hear the difference (love it as an integrated amp though). I cannot speak to the synergy with your cans specifically, but if they are the same cans Peter brought over (one of the Senn cans I'm sure) I didn't much like them in comparison to the Sonys, for whatever that is worth. The Senn's I heard sounded much less lively and dynamic than the Sonys on the Berning. Peter can say which model they were. So, as Peter indicates, it may be a matter of Synergy...or? Peter has both Senns and Sony so he could speak more to that.
Marco
Marco