Note: This article is based upon the video "My FAVORITE Headphone DAC/AMP” made by DMS on his YouTube channel and is printed here in partnership with DMS. The review was originally posted on January 28th, 2022. Edits have been made for clarity and length.
Hey, guys, DMS here. Today we’re talking about my favorite headphone DAC/Amp. Let’s check it out. Now, after about five years of publishing reviews of headphones, DACs, amps, calling something my absolute favorite….well, that’s pretty high praise. Let’s talk about this thing and what makes it special.
This is the FiiO K9 Pro. It has an aluminum chassis. It’s pretty heavy, and it’s an all-in-one digital analog converter, amplifier, and preamp.
This is the first time that I’ve had a THX amp that I really really liked. If you know the channel well you know that things like the THX AAA 789 really weren’t to my tastes. I did kind of like the THX AAA one, but mostly because it was a great value. This doesn’t quite feel like a THX amp. It feels better.
Now, before this, my favorite DAC was the Matrix Element M. Now, that’s a $2,000 DAC, and I used that for close to a year as my daily driver. Before that I was using the DCS Bartok, which is a $17,500 DAC. The K9 Pro reminds me a lot of that. Now, granted, they are very different price points. They are different DACs. They’re different amps, but the things that the K9 Pro does well remind me so much of the things that the Bartok did well.
Usually, THX amplifiers sound congested to me, especially in the highs. They’re always very clean, very detailed, but I feel like everything is just all forced together into one space, and it’s just like a train line of detail straight into your ears. There’s no space for it to breathe. But the K9 Pro goes in the other direction. We still have all of that detail. We still have everything that I enjoy about the THX amps, but none of the things that I don’t enjoy. It feels spacious. It feels smooth. Like the DCS Bartok, it feels almost like the highs have a rolling sound to them–not rolled-off, not recessed, and still very fast, forward, and detailed, but not in a way that’s painful or sibilant or overly aggressive. The amp does a great job of taking things in my collection that would normally be sibilant and making them sound smooth, without recessing the highs, which is so interesting because it’s an extremely neutral amp, and I wouldn’t by any means call it warm. It’s just smooth.
I personally think this amp pairs insanely well with things like the Sundara and pretty much any planar above that, though I also did really love it single-ended with the HD 6XX. On the 6XX, even with worn pads, it really brought out the highs and gave the bass more punch than I’m used to on other amplifiers, but it still doesn’t color the sound. It sounds more like it’s just filling in the gaps in places where headphones are missing things.
I do have a couple of complaints. One, is that the text on the front of the amplifier is a little hard to read unless you hold it at specific angles. Two, the volume knob is a digital pot, so there’s about a half-second of delay before the volume changes. Now, I haven’t had any problems with channel imbalance, which is nice. That’s the benefit of a digital pot: the channels are pretty much always going to be locked at the same volume, so no matter how low it gets you’re never going to get left and right imbalance.
Now, as far as power goes, this doesn’t have the most power. It’s plenty powerful enough for the vast majority of headphones in most peoples’ collections. You’re not going to power something like an HE-6 on this, but I think this is more than enough power for things like my Aeon Noir, my Focals, my HD 800s, my HD 6XX, 650, Sundara, the 600 Beyers, or even my Dianas.
So if you’re the kind of person that likes to listen to ear-shattering volumes, and you have a Diana, you’ll probably want something with a little bit more juice. I think if you listen at any normal or above-average hearing levels, you’re going to be fine. This definitely gets far louder than I would ever be comfortable putting sound into my ears.
Now, that is a lot of positive things to say about a DAC/Amp, and it’s not perfect, but I really feel like this isn’t sacrificing anything. I feel like this is actually comfortably an all-in-one, no compromise solution, and it has room for scalability. I can use this with another DAC. I can use this as a DAC. I can use it with all kinds of setups. I mean, I guess the only limitation is I’m not going to be like putting it in my backpack and carrying it around to use on a train or something. But FiiO really nailed this, and it’s going to take something really crazy to take this thing’s place on my desk. Right after this video is finished, that’s where it’s going: right back on my desk next to my computer that I use every single day. Of all the things in my collection, this is what I want to be listening to.
So there you go. Glowing review. FiiO K9 Pro. Do I recommend it? Absolutely.