I recently purchased the MF Nu-vista 800 and added the Holo Spring3 DAC.
the voltage.out put on the Spring’s outputs.is double of the Nu-Vista 800 inputs. The resulting sound output was obviously distorted. I didn’t expect to have any issues and MF doesn’t publish that spec in their owners manual.
I had to add attenuators to the XLRs on the Nu-Visia side. An expense, and issue I did not foresee. Apparently, a common issue with MF.

