https://www.head-fi.org/showcase/sony-mdr-z1r.21971/reviews#review-21989 Here is a review where I compare the Z7 to other Sony flagships. The Z7 is kind of a love it or hate it headphone. It’s truly the Sony house sound, and maybe an exaggerated take on it? My hearing says things I’ve done like the Kimber Cable helped change it for the better. Using the 1A is one of the ways to make it better. It may be off though with certain combinations of amps? Though there is many ways to make the Z7 sound fairly good. I used the Schiit Asgard One and fed it with the Sony TA as simply a DAC and the Z7 (stock-cable) was pretty fabulous? Though not as great as using the Kimber 4.4mm? Also for my taste the 1A wins out over the Asgard One? So there is an example of the 1A not only keeping up but maybe beating out a fairly powerful class-A desktop? The 1A has the power and seems to offer a cleaner more detailed response than the Schiit Asgard? Much of this is due to the Z7 being easy to drive? In this situation the Asgard is going to offer slightly more power, but it’s the overall sound along with the resolution and tightness that makes the Z7 and 1A so good? But in reference the Z7 and Sony TA really takes the cake....as expected. Due to the Sony house sound the Z7 is both slightly dark but still has a treble spike added to make it a V signature. The Schiit Asgard is on the bright side but it still works OK? The reason the Kimber is important is the 1A is on the flat-to-slightly bright side, I would not call it a dark DAP, so adding the Kimber smooths out the whole signal, and because the Z7 has warmth it’s a good combo.