Sylvanor, you may be going about this the wrong way.
If you like your amplifiers it is possible that your issue may be better fixed by moving into a tube based preamp which can sound warmer than the Pass, or perhaps changing your cables, power conditioner or dac may be the answer.
You need to look at the entire chain and assess its contribution to sound.
Sometimes just changing a cable or adding a power conditioner can bring the system's sound to exactly what you are looking for.
Dave and TroyAudio Doctor NJ
If you like your amplifiers it is possible that your issue may be better fixed by moving into a tube based preamp which can sound warmer than the Pass, or perhaps changing your cables, power conditioner or dac may be the answer.
You need to look at the entire chain and assess its contribution to sound.
Sometimes just changing a cable or adding a power conditioner can bring the system's sound to exactly what you are looking for.
Dave and TroyAudio Doctor NJ