The Colorfly C4 portable music player causes polarized reactions - prospective owners will either fall in love or hate it almost immediately. In over 30 years of reviewing all sorts of audio devices from phono carts to DACs to power amplifiers and speakers, I've rarely come across a device that I so wanted to like that left me so consistently stymied by primitive ergonomics.
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Priced at $799, the Colorfly C4 is positioned to compete with the Astell & Kern AK100. For only $100 more than the AK100, the Colorfly offers several key features, including the ability to function as a sample-rate converter and SPDIF DAC. According to Colorfly's site, the C4 is the first portable player to support 192/24 files, as well as the first with under five picoseconds of jitter and the ability to drive 300-ohm resistance earphones.
Unboxing the Colorfly C4 will provide prospective owners with their first surprise: it's much larger than most portable players. The C4 is slightly longer than an iPhone 5 at 0.75 inches wider and twice as deep. The top surface is finished in what can best be described as an antique brass finish. It reminds me of an old Emerson humidifier I used to own. The back and sides of the C4 are made of "black walnut from North America." On the back is an intricate hand-carved logo featuring two library lions on either side of a shield with a big C on it. I guess that's Colorfly's coat of arms. Impressive. The C4 comes with 32 gigabytes of internal memory, as well as a slot for a microSD card. The largest card currently supported is 32 GB.
The C4's ergonomics are as unique as its looks. You won't find a touchscreen or even a regular keypad setup. Instead, Colorfly decided to reinvent the control surface. The top third of the C4 has a color display; however, instead of a touch-sensitive control face, the C4 has a large ALPS professional volume slider on the right hand side and two overlapping squares with six pushable function buttons on the left. Below the upper square is a two-button switch for changing the preprogrammed EQ and the sample-rate converter settings. At the center of the two overlapping squares is a square red button that functions as on/off, play/pause, and select. All of the C4's inputs and outputs are located on the bottom edge of the player. There you will find a micro-USB connector, an RCA SPDIF input, an RCA SPDIF output, a microSD slot, and two stereo headphone jacks.
All charging and transferring of files to either the internal memory or microSD card is supposed to happen through the USB connection. I found that the charging functions worked correctly, but transferring files via USB was less successful. After several minutes of copying files, the operation would cease, and an error message about an incorrectly removed USB device would pop up on my Mac's desktop. Some files were copied successfully, but not all. After multiple tries, I resorted to adding files to a microSD card via a USB card reader and then using microSD cards as my primary music file source with the C4. The C4 preferred files to be in folders rather than just residing at the root level. Any music files that were not in folders were not recognized.
Once you have some music in the C4, the rest is relatively straightforward ... almost. One quirk I found was that, if I tried to change settings while music was playing, it was impossible to back out of the nested menus. No amount of pushing the "back" button made any difference. Once the music was paused or stopped, the back button functioned properly. Another ergonomic quirk was that, while the C4 will play higher-resolution FLACs, it can only play them if they are 16-bit depth; 24-bit FLAC files, such as the Beatles collection released on USB a couple of years ago, won't play on the C4 unless converted into WAV. According to Colorfly, the C4 supports FLAC 16-bit up to 192 kHz, WAV 24-bit up to 192 kHz, APE, MP3-320, and Ogg Vorbis file formats.
Best audio practices dictate that you should always turn down the volume on any device when you turn it on or off. This is especially true for the C4. If you fail to turn down the volume, you will hear a thump when you turn the C4 off and once again when you turn it on. If you were listening at a high volume, the thump will also be loud. While the C4 is certainly not the only device that makes a turn-on/off noise (the Mytek 192DSD DAC also has a turn-on/turn-off thump), it's one of the few that doesn't mention the issue or suggest a "best practices" solution.
The C4 has two headphone connections: one is for standard 0.25-inch (6.3mm) stereo jacks, and the other is for stereo (3.5mm) mini-jacks. On the Colorfly site, you can find fairly comprehensive tests of the C4 for 16-, 32-, 100-, and 300-ohm impedance devices. With a 32-ohm load from the 3.5 jack, the C4 puts out a maximum level of 618 mV. With a 300-ohm load in the 6.3 jack, the C4 puts out a whopping 1,988 mV of output.
Unlike the power source in some players, such as the HiFiMan 601, the C4's battery is not replaceable. It's hardwired into place. If long battery life is important to you, you'll be disappointed to learn that the C4 won't keep going and going. I got slightly over 3.5 hours from a full charge at first. After a few cycles, battery life improved somewhat but, if you are planning a long trip, I suggest getting a couple of USB battery/power sources to supplement your power options so that you don't end up having to pretend you're still listening to music at the five-hour point in your trip.
Read more about the Colorfly C4's performance on Page 2.