I had the opportunity to work with an RTX6001 this week, and thought I would share some test results of the instrument.
Due to time constraints I was limited to using RMAA. The loopback performance from unbalanced out to balanced in was decent at 24bit 96kHz:
Performance was mostly limited by mains and it`s harmonics:
I used the default RMAA settings so the so the graphs have FFT gain, but the SNR is shown in the table.
I found it very interesting that I could improve the unbalanced mains noise by 10 dB by either using a much heavier gauge AC cord, or running a ground wire from my power bar earth ground directly to the output jack ground. The results above were with the heavy duty ac cord.
Good news is that the power supply noise was common mode and balanced loopback was better:
Results at 16 bit 44.1 decreased as expected with the bit depth noise masking the mains noise. Here are results 16/44.1 unbalanced:
Neither outcome was quite as good as hoped (leaving some dB on the table) but I find these prosumer setups are extremely sensitive to PC noise and ground and these were best results off 2 different PCs and best cables in my collection, with careful dressing. All results optimized the ADC for lowest input gain possible without sacrificing noise from dropping the level on D/A too far digitally.