I've tried HAP-Z1ES USB into Oppo 205, Denafrips Terminator, & Marantz SA-10. There were some problems with Terminator which uses Amanero USB interface, so it was returned. I don't have any problems with both 205 and SA-10 which use XMOS USB interface.
Eventually, I discovered the Z1ES limits the sound quality since I have 2 DACs which also have transport, so I can compare easily. Not willing to spend too much money on player/renderer, I built my own using Intel NUC 7i5BNH with linear power supply and 2 internal SSDs, using Win 10 Pro with HYSOLID free player. The sound from NUC into SA-10 DAC is much better compared to using Z1ES as player into SA-10, even after upgrading the Z1ES internal drive to SSD.
Eventually, I discovered the Z1ES limits the sound quality since I have 2 DACs which also have transport, so I can compare easily. Not willing to spend too much money on player/renderer, I built my own using Intel NUC 7i5BNH with linear power supply and 2 internal SSDs, using Win 10 Pro with HYSOLID free player. The sound from NUC into SA-10 DAC is much better compared to using Z1ES as player into SA-10, even after upgrading the Z1ES internal drive to SSD.