The best I've heard my 4z's are on my Chord Dave, but that would be the ultimate tier. My Hugo 2 and Centrance Hifi-M8 V2 are also great pairings with the 4z's if you want to go portable. They pair very well with my iFi Zen Dac V2 and Zen Can, GX-X MK2, Formula S and I loved them on the Yulong Aquilla II.Actually, I wish that anyone can share their experience with the 4z regarding the amplifier that has the best synergy with the 4z. As you know 4z has a pretty low impedance at 15 ohm while has a sensitivity of 98db/1mW. While even a mobile phone can churn out decent volume on the 4z, a proper amplification will bring out the best from this Audeze unique flagship. Please do share your experience, because as a low impedance (15ohm) it is definitely has different synergize than other higher impedance planars in term of amplification matching. For example an Audeze LCD 4 at 300ohm will sound the best with most tube amps for example, while 4z I never tried with one except the hybrid WA7 which works quite fine. Any suggestion, experience, or insight is most welcome. Cheers!
If you are noticing the pattern the LCD-4z's sound great on just about anything. The slight warmish signature of the 4z's sound the best with neutral to brighter sounding gear in my opinion. So amps like the Headamp GS-X Mini, iFi Pro iCan, Bryston BHA-1 and some others would be a great starting point. As you climb the ladder you can consider the Violectric V550/V590 or Benchmark HPA4. There are just so many options out here. It'll come down to your preferred sound signature.