Big Shoutout to FiiO for sending the K5 Pro demo unit for comparison to the K3!! I am not being compensated for this review, but they were kind enough to let me keep the units. Thank you for your continued support!
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Hey there friend, and Welcome aboard!!
Let’s start with a quick chart!
FiiO K3 vs. K5 Pro
FiiO K3 DSD256 | 384K/32Bit USB-C DAC and Headphone Amplifier for Home and Computer(3.5mm Single Ended/2.5mm Balanced/Coaxial and Optical Digital Outs) …
FiiO K5 Pro AK4493EQ | 768K/32Bit and Native DSD 512 decoding Deskstop DAC and Amplifier for Home and Computer(6.35mm (1/4 in.) Headphone Out/RCA line-Out)
Op amp: LPF Op Amp: Texas Instruments OPA1642, Driver Op Amp: Texas Instruments TPA6120
Dimensions: 4.7 x 5.1 x 2.2″ / 12.1 x 13.0 x 5.5 cm
Warranty: 1 year.
Power: 15VDC, 1.5A
Gain Switch: 0, 6, 12dB
How about build?
The build of both of these units is fairly solid; the K5 is significantly heavier than that of the K3 and that’s to be expected given the K3’s much smaller foot print and knack for portability.
The K5 isn’t hefty by any means – it’s actually fairly light for a unit of this stature, but still feels pretty solid overall. It’s a bit lighter than the iFi Zen DAC/Amp overall, coming in at 436g vs. 491 for the Zen. The K3 is only 82g by contrast, but still doesn’t feel cheap.
At 1.08 lbs., the Zen does feel more substantial as a full time desktop amp, but I still love the way the K5 looks and feels sitting on my desk.
The K3, though light, was an upgrade over the E10K in the weight department as well. It feels a bit more robust than it’s older, more stone age looking brother. Related:FiiO K3 vs. E10K [The Definitive Guide]
Both switches on the K5 feel great to flick, while the large ADC volume knob on the front is mega satisfying to turn.
The K3’s ADC volume pot actually feels just a smidgen more robust, and both the gain switch and bass boost feel satisfying as well. That’s not to say that the bass and gain on the K3 weren’t, but they are a bit harder to flick on and off whereas the K5 makes it a little simpler to flick.
Both units come with some adhesive padding for desktop use, but the K3’s are longer cylindrical pieces vs. the button adhesives on the K5 Pro. The original E10K utilized these buttons as well, and overall I think they’re more effective. What’s cool about the K5 Pro is that they have already been fitted with some out of the box, and you have 4 more at your disposal that have been included separately if need be.
All connections on both units feel nice and robust. There’s a sense that these are indeed quality units that will hold up over time, and also work in a myriad of ways as well.
Let’s get into some features of both!
Features & Usage
I’ve always felt like FiiO gives plenty of bang for your buck in all of their products. To this day I still have an E10K sitting on my desk because it’s so valuable. I can do plenty of things with it, and the K3 only improved on that notion.
The K3 has:
Line Out. An incredibly useful feature in that you can use the K3 as a DAC into any amp that supports line in/out. I personally have used the K3 with JDS’ Atom to fine effect, and have used the E10K with a few different amps as well.
Coaxial Out. Use this to connect to anything that supports coaxial in (TV, Receiver, etc.)
Optical Out. Same as above.
USB Audio 1.0 & 2.0. The cool thing about the K3 is that you can literally plug it in and start playing music without any drivers via USB 1.0. If you want to use USB 2.0, just go to FiiO Support, and download the USB DAC driver. Related:What is a USB DAC? Then simply turn the unit off and disconnect everything (basically a reboot). Now you can use USB 2.0, which supports DSD256 and up to 32-bit/384kHz. The USB 1.0 section only supports up to 24-bit/96kHz files.
Balanced 2.5mm Headphone Input.
Standard 3.5mm Headphone Input.
ADC Volume Pot. No channel imbalance issues at lower volumes. A complaint I’ve heard quite a bit from regular volume pot’s of the past.
LED Indicator. Supports DSD, as well as file formats up to 32-bit, 384kHz. The Small Led light next to the volume pot indicates the format you’re in. Blue is 44.1 or 48kHz, Yellow is anything above 48kHz, and Green indicates you’re playing a DSD file.
USB Type-C Input.
So you’re getting all of that for just a hare over $100. It’s pretty amazing if you ask me, and a big reason why I don’t see myself selling the K3 anytime soon. It’s just really valuable and makes a perfect entry level foray into the audiophile world.
The K5 Pro is a bit different, but still just as awesome (if not more so). Let’s take a look at what it has:
RCA Analog Outputs. This is a great feature in that you can hook the amp up to separate studio monitors and play music that way. What are Studio Monitors?
RCA Analog Inputs. You can also use the RCA ins to receive a signal from a source (for instance a separate DAC). Right now I have the iFi Zen Blue hooked up to the K5 and I’m playing music wireless through my phone! Just snag a pair of RCA to RCA cables.
Optical Input. This is my favorite feature of the K5, as I can output the signal from my PlayStation 4 into the K5’s Optical Input and use it as a gaming rig! What’s even better? Plug it in and sound is coming from the K5 into my headphones instantaneously. No need to even mess with the audio settings inside the PS4’s control panel/dashboard.
Coaxial Input. Receives audio via any of your devices that support Coaxial Out (TV, Receiver, etc.)
USB Type-B Input. You’ll be using this most often with your computer.
15 VDC Power Jack. Plug this in to a wall outlet for powers.
Input switches. The K5 Pro comes with 3. They are labeled 1, 2, and 3, with S, L, and U next to each number respectively. 1-U is for USB, 2-L is for Line In or Line Out, and 3-S is for S/PDIF I presume (it’s labeled Coax or Optical).
3 level Gain Stage Switch (0, 6, 12dB). This is my second favorite feature on the K5 Pro, and they label it with one circular dot, 2 circular dots, or 3. I’d feel comfortable driving most any headphone with this unit. On middle gain with the HD600, I’m finding there’s plenty of headroom. I’m on about 2-3 o’clock and find it more than enough. I still have one more (high gain) to play with if I need it. This will mostly be utilized with harder to drive planar magnetic headphones that aren’t efficient at all. I’m thinking 91-93dB cans like some HIFIMAN offerings, AKG, etc. The HD600 sits around 97dB and isn’t too hard to drive out of most amps (even the K3 does pretty well with it).
6.35mm Headphone Input.
As you can see, the K5 Pro is capable of quite a bit as well. Let’s take a look at power output, and find out which one of these gains an edge.
To be blunt, the K3 is fairly under-powered on paper, but surprisingly drives my HD600 pretty decently even despite only pumping out 220mW into 16 Ohm and 120mW into 32 Ohm. Do be aware that the gain has to be on and you’re pretty much maxing it out, but it does get plenty loud enough.
The K5 by contrast supplies 1.5W (1,500mW) at 32 Ohm and is rated for 16-300 Ohm headphones. Keep in mind this suggestion is being somewhat conservative. As mentioned before, I’d feel just fine driving a less efficient headphone out of the K5 Pro.
The main takeaway is that the K3 really isn’t designed for higher impedance, low sensitivity cans, and I wouldn’t rely on it for most inefficient HIFIMAN’s or AKG’s. It’s just powerful enough to drive an HD600.
The K5 Pro however is built for harder to drive headphones and in that way should become a mainstay on your desktop for a long time!
Video Comparison (Coming Soon!)
Click to see the K5 in action!
Here I had the Zen Blue paired with the FiiO K5 Pro, with the Zen DAC on top.
Here I was comparing the K5 to the K3.
Now for the most important part, how do they sound in relation to each other?
Fortunately for us, this is a really easy comparison and a more significant one than I was expecting. Its not that one was necessarily better than the other; rather they both have a different flavor, and which you prefer comes down to your sound preference.
Even when I say significant, it’s still pretty subtle of a difference in the grand scheme of things. With some tracks you might not even be able to notice.
For instance, on A.CHAL’s “Matrix”, I didn’t hear anything vastly different going on. On Cautious Clay’s “Blood Type”, The K3 perhaps sounded slightly more open, and a bit cleaner. The K5 seemed to have a warmer tilt.
After these 2 tracks, the sound differences did start to manifest a bit more clearly.
The over arching theme was that the K5 Pro is more of a relaxed listen. It’s more melodic and fluid sounding vs. the colder, cleaner, and somewhat more brash sound of the K3.
Brash doesn’t necessarily denote a negative connotation, but in relation to the K5, it’s definitely more in your face, forward, and aggressive sounding.
This notion was also very much apparent on Common’s “Little Chicago Boy”. It’s just edgier sounding coming out of a K3. More cold. More sterile. Common’s voice is a bit more prominent/forward in the mix as well. It kind of jumps out at you. The K5 Pro by contrast sounds warmer, more relaxed, and more laid back. It’s a more inviting sound overall.
On “Doves in the Wind”, by Kendrick Lamar and SZA, I found more of the same to be true. The K3’s vocals were more forward, with the overall sound being snappier than that of the K5 Pro.
On Odie’s “Noise” and “Night Terrific!” it’s more of the same. You can make out more of his subtle vocal inflections. He sounds a bit crisper through the K3. On the K5 pro, he comes across slightly warmer. Out of the K3 at :19 seconds (Noise), his breath can be heard a bit more clearly.
Even with all that said, the sound differences are fairly subtle, but definitely more noticeable than some other sound comparisons I’ve done.
Which of these you go with depends on many factors that we’ve previously discussed. The K3 can technically be used with your phone (and an appropriate adapter), but you may just end up with a dead battery, as it’s bus powered and should be used at your desktop primarily. The K5 is strictly a desktop amp and should be treated as such.
If your preferences lean more towards warm, lush, fluid, and inviting, the K5 Pro is the better option. If you like a leaner, cleaner, more sterile and aggressive sound, the K3 performs very well. It’s just going to be snappier sounding overall, with a slightly more revelatory character. Detail oriented cats will love the K3, while more laid back homies will prefer the K5 Pro. I also think the K5 fares better over longer listening sessions; you’ll want to kick back and let the music play without wanting to skip around quite as much.
It was really cool to be able to use the K5 with the iFi Zen Bluetooth DAC. I’m also loving the optical input, as it becomes a dedicated console gaming rig if I so choose.
If you like a warmer sound, need a great amp for PC or console gaming, and/or want to hook this bad boy up to some studio monitors, I’d invest in the K5 Pro without hesitation.
If you prefer a somewhat colder sound, own easier to drive headphones, and or/ plan to utilize the balanced jack, the K3 makes a fantastic option. It’s also very versatile and can be paired up with any amp that supports line in/out.
Stu is determined to help you make sound decisions, and strives to deliver the best and most in depth content on the internet! In his spare time, he likes to fish, paint, play guitar, pray, rap, make beats, take photos, record videos, graphic design, and more. His sense of humour, coupled with a knack for excellence and strict attention to detail are what allow him to stand out in an crowded industry.