I'm currently testing this unit alongside the SA300 in order to find a replacement for the Fosi BT30E that just had too many QC issues, which sucked because it's the only amp (alongside clones like the Douk) that has a freaking sub crossover and level control.
FYI I've got a 2.1 setup, 2 passive bookshelf speakers and a powered 10" sub in my PC desktop setup with a SB AE-5 Pure soundcard. Love the card, the DAC is better than either of these units, which is fine, as I'm running analog out to the amps.
I really want to like the MX3, but I can't. One huge flaw (not sure if it's a defect or not) is that yeah, you can have it play to speakers with the headphones plugged in (one of the reasons I got it since the SA300 for some reason decided headphones out was a bad thing) BUT IT DISABLES THE SUB OUT. What??? Like...what?? If I want the sub out on the MX3 to send signal to the sub, I have to unplug my headphones. That's a killer, man for real.
Also, when getting near +30dB (max) volume, she cuts out...every time.
So, I don't know if I got a defective unit or what, but it's going back. I'm just not sure if I want to deal with getting a replacement to test.
A bit surprised at how poorly this amp performed in the tests on this thread. It got louder and had less distortion at high volume in my system, than the SA300.
I really do like the SA300 though. If it had a headphone jack and optical input, it'd be one of the best out there.
I really wish, though, that these amps would for the love of god put a freakin' sub x over and level control on their amps. The really cheap Chinese companies selling the units labeled as "Fosi Audio", "Douk", and "Nobsound" do it, but man their quality of like, EMF shielding, RCA input, proper grounding, etc really suck and they're like anywhere from $30-$70 less than SMSL and Topping. I just don't get it because one of the primary uses for these 2.1 channel mini amps is...2.1 channel sound...so why can't I control how much low end gets split between my speakers and sub? I'm probably going to see if I can use my UMIK-1 and dial in the freq response going L/R out to the amp, and sub out from the AE-5 Pure to the sub. That bugs me though because don't like using digital volume control, it diminishes SQ by cutting bits off as volume goes down, I much prefer using the analog volume of the amp to control everything and leave the PC volume at 100%. So frustrating.
Probably gonna grab the Loxjie, it actually measures better than this one AND has a headphone jack.
Trying to find a decent budget 2.1 setup for my PC is frustrating. Unfortunately, I burned most of my spending $ building the PC, getting the desk, monitor, sub, etc...and I can't drop 400-500 on a decent amp.
Ugh.