I've been thinking about since the video guide Fosi provided shows it with the Sparkos ss3602 but honestly have no issues with the sound with the stock opamps and the swap isn't exactly easy. Would likely have to get a few new tools too.
Looks like when it's set to fixed output the SMSL SU9 has the standard line output of 2 volts for RCAs and 4 volts for XLRs but then XLRs go up to 5.3 volts if you're using the volume control.
So... the first thing to try would be to just set the SU9 plugged into the ZP3 at fixed output, which...
First product announcement. Looks like it comes with a remote, which can control volume.
https://www.audiophonics.fr/en/preamplifiers-volume-controllers/fosi-audio-zp3-p-20776.html?srsltid=AfmBOopFRnF5QhJfuRAcHhMgaUeWWnTzXy2v83QKFkohd9fetsmA7PG_
Does anyone know what the Vrms for balanced line out will be for the ZP3? Hoping this will be in-line with the Schiit Kara but in a more compact form factor and lower price point.