I just plugged in my Flex this evening and did a quick setup, so here are some initial impressions and observations.
I didn't have time to set up EQ or anything. The plugin software is fine and easy enough to use, and I like how changes made in the UI are instantly reflected in the audio. I just set up the inputs, routing, and crossovers for my speakers and two subs. I was up and running that far within about 10 minutes.
After getting it set up and I started listening, there was an immediate improvement in sound quality. This is because I was using 70 Hz 12dB/oct inline passive high pass filters on my mains amp, and I was using the Crown amp's built in 24dB/oct crossover set to 70 Hz low pass for the subs. It worked okay, but with mismatching slopes, the mix was not nearly as good as matching them perfectly and actively in the miniDSP. This was a very nice upgrade, with the bass rolling off more smoothly at the crossover point.
The volume knob motion is not smooth, but instead is stepped/notched for each 1/2 dB increment. I initially did not like it, but I'm getting used to it. I will be using it for primary volume control, so I guess I better make friends with it. I really love the dB reading volume display.
I plugged it into a power strip on a smart switch with the rest of my desktop audio and noticed the Flex turns on with the wall wart getting power. This is what I was hoping for, and I'm glad I don't have to turn it on manually.
Switching between presets while listening to music incurs a 4 second audio drop out. I guess it's fine, but I wish it didn't drop. I plan on using the 4 presets for:
- preferred EQ setup
- reasonable bass cut to the subs for night mode
- slight bass boost on the subs for low volumes
- speakers only with no subs or crossovers
The USB audio input has noticeably less gain than the TOSLINK. Not sure what's up with that, but I can feed it either one from my Mac. Striking that comment as it appears to have been an error. Speaking of USB, the miniDSP Flex is the only DAC that I have ever plugged into my Mac that does not pick up any USB ground noise from the computer's CPU. I've always had to use USB>TOSLINK decouple the ground between my computer's USB and my audio setup. This is the 5th DACs I have tried on my Mac in the last few months (Schiit Modi 3, Topping D10s, NAD 3020 V2 internal DAC, Topping E30), and every other one of them passes CPU noise into the speaker and you can clearly hear buzzing, the kind where you can hear it change when you move the mouse. The miniDSP Flex is 100% silent and picks up no USB noise. I was not expecting that, but I'm super happy about it.