Monoprice Monolith THX-AAA Dual 788 / Dual AKM4493 DAC/AMP Review

That unit on the bottom there is the new THX-AAA powered headphone amp by Monolith - the high end brand from Monoprice. This fully balanced amp and dac features THX's new low noise, low impedance, high power output THX-AAA 788 amps with a pair of AKM 4493 DACs in a small unit that is packed with other goodies.

I picked this up the the first few days it came out and have been using it for about a week now. So far, I really dont have too many complaints that are dealbreakers but here's some quick impressions.

Build Quality:

The build is great. It has a nice hefty and well put together metal chasis with a great volume knob. The inside board is well laid out and extremely clean. The front has balanced XLR and single ended 1/4 inch headphone jacks. On either side of the volume knob are a menu button and an enter button. These buttons do feel a bit cheap compared to the rest of the unit but are quite usable.

The display is a light blue OLED which displays a lot of information at once.

On the back, there are XLR-inputs, RCA, Coax, Digital Toslink inputs, and RCA outs. No XLR output unfortunately.


I found the menus to be quite cumbersome at first. There's a lot here!

First off, the menu and enter buttons are not placed next to each other, so using the menu is a struggle sometimes. But once you get the hang of it, it's not too bad.

The first set of menu items is the built-in Equalizer. You have the option of doing a quick Bass/Treble EQ (Shelf-EQ) or a 5 band parametric EQ that lets you customize very finely. You can pick which frequency, the gain level and the Q-factor. It's quite handy if you know what you're doing!

The second set of menu items is pretty much useless and a waste of space. It's Dynamic Range Compression. Why would any one want to reduce the dynamics of a song? WHY?

The third set is DIRAC, which is a DSP. This new DSP is called Sensasound II by DIRAC, and it works very well for some songs. Basically it manipulates the crossfeed and extends the height and depth of the soundstage while trying to maintain the width, creating a 3D stage in front of the listener. It works very well for songs that do not have heavy bass/beats emphasis. In songs where you want to feel it more than hear the intricacies from your surroundings, you'll lose a lot of richness and fullness to songs.

Finally, the last set of menu items is the Settings, which is where you'll find Line Out option. I wished this was active all the time.

The Enter button, when held down, will activate the Device input. I have the amp connected to my PC via USB and the TEAC PD-301 CD Player using Coax and I constantly use this function to switch devices.


I have to say, the THX amp is extremely clean. EXTREMELY clean sounding. Yea. It is as advertised. It sounds transparent, whatever that means. I never feel like anything is overly emphasized and music sounds ultra smooth throughout and is well extended. It will sound a little leaner than other amps, and thats quite evident on those heavier songs, but the detail that is put out on this amp is excellent.

Overall, I'm very happy with this purchase. I do want to make users aware that there were some bad shipments sent out to some users that had a BETA version of the firmware. Luckily, I had v1.01 on my unit and did not have the same issues as what Amir of Audio Science Review experienced. Hopefully, he will be able to get a production unit to test in the future.

Until then, I am happy to report my findings. Great sound. A little clunky UI (at first), and could use a remote. But otherwise, the music speaks for itself.