FiiOK9 Desktop Headphone Amp/DAC - AKM Edition FiiO K9 Desktop Headphone Amp/DAC - AKM Edition

I very much like the build quality. The packaging it comes in, including a nice brown outer "mailer" box with a handle and an unbroken seal to indicate whether it's been opened as well as a scannable QR code with a scratch off number to verify authenticity immediately made me feel like the product would be high quality and eased worries about potential buyer's remorse.Once opened, I could see the entire inside of the mailer box was lined with padding. Picking up the top piece of flexible styrofoam revealed an iridescent "K9" logo. Off to a great start!I paired it was a pair of Audeze LCD-X Headphones, which I tested through a small DAC that came with a set of Arctis Nova Pro that I used for gaming to compare and there was absolutely a very noticeable difference (as one would hope). I made sure to limit the output of my Mac to 24-bit 96khz when A-B testing, as that is the limit for the small Arctis DAC.It comes with some small rubber feet to stick on and they adhere very well, with 2 to spare.I don't currently have any devices that support any lossless bluetooth audio codecs, but I'm very glad that I have the option for utilizing that feature in the future.The only things that I really have that I can say I wish I knew already or that I would change are the following, and they are nitpicking:1. If you have an iPhone with a lightning port, the Apple brand lightning-to-USBC cable will not work, as it does not support USB OTG.2. I wish the volume knob had some sort of notch so I could feel the position without looking. The white line has zero texture to it. Also, I wish the knob was metal. It is plastic. And last for the knob, because it sticks out so far, it can potentially be pushed laterally by accident. I wish the mount that it turns on, the knob itself, or both were constructed in a fashion that was sturdier. Perhaps a metal knob would solve this alone.3. The USB-B port feels as though it has too much flex where it attaches to the PCB internally. I don't really use it, but every time I have I've felt uncomfortable with the amount of flexing it does. If the case was designed in a way that it helped secure it better, I'd be happier.4. The sliding gain switch is tough to precisely move to each detent without over shooting, and the travel between the detents is too small, with the switch having too much "play". A 3 position "toggle arm" style switch would be much better. Or the same style, with more travel between each discrete gain level and detents that make it very simple to move one level at a time without the feeling that it could get stuck between two gain levels would be optimal

Seems like they’ve ironed out issues from previous iterations of the FiiO K9 that had overheating issues or straight up died. Wish they made it much more transparent which model was which, the FiiO K9 AKM edition (2024) is currently the latest.

My Sennheiser HD660S2 never sounded this good on the K7.I was quite impressed by how it was delivered to me. It came in a cardboard box with a plastic handle. Inside it was lined by some very thick foam protecting the actual product box. Great job on the shipping FiiO.I’ll list my thoughts on this beast of a unit below;1. Volume: The first thing I noticed was the volume knob actually working the way it supposed to and not that janky volume knob of the K7 which was useless before the 12 o’clock position after which it sought to deafen you with the slightest movement of the knob after 12. The K9 AKM knob evenly increases and decreases the volume along the range of its movement and it’s pleasing to the touch.2. Gain settings: This amp is loud AF. Mid gain on the K9 AKM is louder than the high gain on the K7. I seriously cannot tolerate high gain using my 660S2 because it’s too loud for me and I love blasting music on my headphones. Tracks I’ve listened to never gets distorted no matter how high I raise the volume on mid gain.3. Sound: Much more impactful and detailed than the K7. The treble seems to be more detailed but never harsh or fatiguing. I am picking up minor background sounds in some tracks I never noticed before on the K7. Vocals seem to be pushed forward a bit more and the bass hits harder. Now it’s not a day and night difference but it is a noticeable one.4. Build: Built like a tank. I read this was a heavy unit but I was not expecting it to be this heavy. I have to use both hands to move this beast of a DAC/Amp around. The aluminum housing, in typical FiiO fashion, is a clean and pristine finish that’s beautiful yet elegant. Kinda wish they used the OG FiiO logo though.I am greatly impressed by the FiiO K9 AKM and I think I’ve reached my end game DAC/Amp with this mammoth of a unit. This combined with my HD 660S2 is a match made in music heaven that gets me so engrossed in any track I play. If you have the budget and are contemplating between the K7 and K9 AKM go for the K9 AKM. You won’t regret it.