Extremely Neutral, CLEAN Amplifier
After picking up a pair of Audeze LCD-X a few months ago, I’ve been getting to know them while driving them off a Schiit Fulla 2. It wasn’t a bad experience, but I was curious to see what these headphones could do with a more capable amp. I looked around in the $200-$500 range and came away with a few choices, and I ended up going with the THX AAA 789 from Drop. If you’ve read prior reviews of mine, you may already know that I primarily work on music with my headphones, so while a pleasant experience is a nice bonus for me, a brutally honest presentation of my music is most important. If my listening chain is making my music sound better than it actually is, I risk stopping work on it when there could be more for me to do in terms of balancing it for playback on other systems. So, with THX’s stunningly low noise and distortion numbers, and the relatively flat sound compared to most of the competition in the price range (according to the research I did, at least), I decided this was the right amp for me. I have to say that I got more than I bargained for.
My first impression of the amp was that it was “fine”. I liked the multiple gain settings for precise volume control. I monitor really quietly, so I use single-ended ins and outs and I’m still around 1/3 volume on gain level one. I liked that it had a nice volume knob with well-matched channels from top to bottom, but the sound didn’t blow me away. At first. I was using an old gen-1 Schiit Modi as my source, and I noticed that on gain levels two and three, there was noticeable background noise. I figured I either had a broken unit or it was my source, because the amp’s noisefloor is low enough that I shouldn’t be able to hear it, so I unplugged the Modi (again, V1, a DAC that is about 8 years old) and listened to the amp by itself, and the noisefloor fell right away. This isn’t a rub against Schiit, that’s an entry-level DAC from many moons ago. So I stepped up my source to the DAC outputs of the Fulla 2 and things improved remarkably. I’ll consider a better DAC in the future, but ideally my studio needs some other upgrades first and I feel a DAC can wait.
So with a DAC now delivering reasonably matched performance to the THX, I could hear slightly more detail, especially in dynamics at lower frequencies, than going directly out of the Schiit Fulla 2. But, I’d be remiss to call it a night and day difference. I kept listening to it in the background as I worked for an afternoon, and then, after a few hours, I took the headphones off and it hit me: I’d been listening for HOURS straight, and my ears didn’t feel it at all. It felt more like I’d been listening for 45 minutes than a few hours. The thing I didn’t hear, but could absolutely feel, was how little distortion there was in the chain now.
I should explain: in pro audio, one of the things that is accepted to determine how much a monitoring system is going to fatigue the listener is how much distortion there is, especially between 1 and 3khz, where the ear is most sensitive. This is such a big deal that, even though 3-way speaker designs are significantly more expensive and don’t offer much, if any, more bandwidth than 2-way designs (since bandwidth is limited more by size than by driver count), they are highly prized over 2-way monitors. Because 3-way setups, even with an extra crossover and more complicated amps, have much lower distortion in that critical frequency range. It comes up in 3-way monitor discussions over and over, and everyone says you have to hear it to believe it. And time after time, people who doubt the cost will be justified use these things and are blown away by how much better their ears feel at the end of a day. Well, I was just blindsided in the same way by a headphone amp. This is the real WOW factor in this amp for me.
Unfortunately, I don’t have many relevant points of comparison besides the Schiit Fulla 2 I was using previously (which is still my DAC). So I will compare only briefly to that in the sense of “this may be what you can expect upgrading from an entry level amp” rather than a critical comparison of the two products. Listening to “El Camino” by The Black Keys, I did a quick back and forth between the two, unplugging and replugging the single ended cable of the LCD-X into each while a few of the songs played (I don’t feel a need to call out specifics, the whole album has a sound to it that carries from song to song). The THX based amp pulled the music out around me a bit more. It actually sounded a lot like what I try to do when mastering a song, I try and pull the listener into the middle of the song, and the THX gave me a similar feeling. I think it comes from a slightly enhanced channel separation, which makes the stereo elements of a mix pop out a bit more (at least, that’s part of what I do during mastering). That is the most noticeable difference, and that’s on $1700 headphones with pretty precise soundstage, so you may not hear or feel that in other headphones with this amp. But what I call, for lack of a better term, the “stereo presence” of recordings comes out more on the THX than on the Schiit Fulla 2.
So, in summary, the amp sounds fine. It doesn’t make the same difference that a great set of headphones makes, absolutely get your drivers sorted first. And, I wouldn’t expect this to make a huge difference for most people even if you do already have headphones you love. I think if you want a specific sound to your amp, the Drop THX AAA 789 really doesn’t bring any character to the table. But, what it did do for me is take a headphone that already is easy on the ears in long sessions and make it even gentler on my ears, and give me the slightest bit more detail while it was at it. For my purposes, that’s A-OK.