Despite smartphones being able to do everything DAPs (digital audio players) can do, it is nice having a phone to do phone stuff and a standalone DAP for playing music.
The main reason a DAP wins over a smart phone is audio quality. It is not secret most phones internal DAC aren't a match against the performance of a dedicated DAP.
With a DAP, there is no battery drainage of your phone plus, DAPs are kind of cool. Kind of like, having  the original Sony Walkman Cassette when they first came out in the 1980s!
There are many DAPs to choose from but if you like a DAP with the old school feel of an offline mp3 player, the HIDIZS AP80 will tickle your fancy.
The AP80 can play standard digital audio files (FLAC, APE, WMA, MP3 and WAV), as well as bluetooth audio in high resolution via aptX, LDAC, HWA and SBC.
LDAC and HWA bluetooth codecs are only supported by headphones (or earphones) that support these codecs such as the Sennheiser IE80S in-ears and Sony 1000XM2 over-ear headphones.
The AP80 supports microSD cards up to 1TB in size with either FAT32, exFAT or NTFS formatting, all of which are good options; however, exFAT or NTFS formatting have no file size limitation and let you take advantage of one of the main features of the AP80 and that is support for DSD ISO files.
If you load 200GB worth of music, it takes approximately a minute to scan the entire music library. Automatic scanning happens every time you eject the microSD card, unless you set autoscan to off.
If the microSD card is never ejected, there is no music scan even after turning off the MP3 player. The music library scan can also be started manually.
The HIDIZS AP80 music player has a grippy volume knob dial for turning the volume up or down without having to press buttons.
When the AP80 is connected to a smartphone, you can  also control the AP80 internal volume from a phone via the HibyLink mobile app.
The power output is probably one of the most important specifications of a digital audio player because it determines, which headphones you can use. The AP80 music player is a low-powered DAP, which can deliver 80mW at 32 Ohms.
The AP80 can handle impedance headphones up to 60 ohms without issues but the higher the impedance rating of the headphones, the lower the volume level. If you plan to use headphones with very high impedance (i.e. 300 or 600 Ohm), you will need a DAP that can output at least 300mW at 32 Ohms.
Left-right stereo channel separation is another important specification to check on a DAP because the lesser the separation the more crosstalk interference you get; hence audio distortion. Any value above 60dB is a decent channel separation.
The AP80 has 73dB channel separation, which is good but the greater the separation the clearer the sound. The AP80 also has a high signal-to-noise ratio (119dB), which means you can use earphones with high sensitivity without background noise.
Being a music player, frequency response is important in relation to the headphones or earphones you use. The AP80 frequency response is between 20Hz and 40KHz with variable 3dB (± 3 dB). If you were to use earphones with a frequency response between 5Hz and 50kHz, the AP80 DAP may limit the earphones, depending on the earphones' variable dB.
The AP80 features a standard 8 preset equalizer (EQ) with custom EQ setting, as well as the MSEB (MageSound Eight Ball) feature you get in the HibyMusic mobile app. MSEB is, essentially, a DSP mixer that lets you further fine tune the audio so, you can make vocals more recessed and sound warmer or darker.
Step counter and FM radio are two other features you get with the AP80 DAP player. FM radio works the same way as a smartphone's FM radio so, you need a pair of earphones connected to the player to act as a radio antenna.
There are four modes for audio playback including sequential, random, repeat same song and repeat the entire playlist. You can also resume play from last and enable gapless playback.
The HIDIZS AP80 integrates two way Bluetooth 4.0, which means the AP80 music player can connect to a smartphone, as well as a pair of headphones for music playback.
The HIDIZS AP80 music player uses an 800mAh lithium cobalt oxide polymer battery that can power the AP80 up to 15 hours when used as a regular offline mp3 player. When using bluetooth mode, battery life drops down to approximately 8 hours depending on codec and volume level as well.
Recharging is done via the same USB-C port that lets you connect to a computer for transferring files, as well as connect to a smartphone via OTG connection (cable not included).
Full battery charge takes approximately 1.5 hours via a maximum 5V/2A input. Fast charging is not supported; hence you cannot use a wall fast charger to speed up charge. Having said this, you can use a 2 amp USB port of a power bank to recharge the AP80 and use the music player while it is charging. The battery is able to hold charge for 30 days when placed in deep standby mode.
Aside from being an mp3 player, the HIDIZS AP80 is also a 32 bit USB DAC, integrating a Sabre ESS 9218P DAC chip, which features jitter reduction algorithms
You can use the AP80 DAP player with a computer to convert digital audio to analog up to 348 kHz in resolution, which is a neat and inexpensive way to improve the sound quality of a computer without having to replace its sound card.
The AP80 also supports USB DAC output so, you can connect the AP80 to an external amplifier. There is also support for Direct-Stream Digital, meaning the AP80 is able to read DSD ISO files (both DSD 64 and DSD 128).
The AP80 DAP player is compatible with mac computers (macOX10 and higher) and Windows computers (XP, 7,8, 10).
Most digital music players either run on a custom version of Android or Linux operating system. The HIDIZS AP80 DAP player runs on HiBy 3.0 OS, which is a light, custom version of Linux operating system licensed by the makers of Hiby digital audio players.
The Hiby operating system is a joy to use but being linux (instead of Android), it doesn't give you access to Google Play Store to download audio streaming platforms like Spotify and Tidal since the AP80 DAP player doesn't support Wifi.
You cannot record audio either since there isn't a microphone built-in to the AP80 but you can take calls as long as your earphones integrate an inline microphone since the 3.5mm headphone jack supports TRRS connection.
The volume can be adjusted in 100 increments. There is an option for low or high gain headphones, and turning on high gain works wonders on some difficult to drive headphones.
There is also a line out setting that outputs through the same 3.5mm jack but you do not want to use the line out option with regular headphones, or risk damaging them.
The 2.44-inch touch screen of the AP80 DAP player has good responsiveness, good brightness and contrast levels and excellent viewing angles thanks to the screen's large 480 x 360 resolution.
The AP80 screen is housed inside a black-anodized, machined aluminum body, measuring 5.8cm high, 5cm wide and 1.4cm thick. Total weight is 70 grams.
The AP80 buttons are also made of aluminum-alloy, while the backside has a 2.5D glass panel. The wheel volume has a red ring accent. The small buttons on the side give you full audio playback control so, you can skip tracks, play/pause, as well as fast forward and rewind.
The HIDIZS AP80 user interface supports a total of 12 languages, including English, Chinese (simplified and traditional), Japanese, Korean, German, Spanish, Italian, Polish, Russian, Thai, French. Font size can be adjusted from small to medium and large fonts.
If any manufacturing defects or functionality issues occur, HIDIZS will repair, replace or provide an alternative product. Buy it. Check out the review of the Hidizs MS2 earphones, S3 Pro and the review of the DH80S dac/amp combo.