This test was done using Jewel IEMs, volume matched in every comparison.
AP80 Pro-X vs AP80 Pro (SE & BAL) – wider soundstage and more holographic imaging; more resolving tonality with better layering and separation of the sounds, more ‘air’ between the layers. I do hear a bit stronger mid-bass punch with Pro-X, and mids of Pro-X have more transparency with a little less coloring. Also, treble in Pro-X has more sparkle and better extension. The same applies to both SE and BAL outputs.
AP80 Pro-X vs AP80 Copper (SE) – Pro-X has a little wider soundstage and leaner more transparent mids, while Copper has a fuller body more organic mids; also, Pro-X has a blacker background.
AP80 Pro-X vs Hiby R3 Pro (SE & BAL) – When I was comparing AP80 Pro vs R3 Pro, I found them to sound identical. So, in comparison to Pro-X, the same difference will apply as I found between Pro-X and Pro. Pro-X has wider soundstage, better layering and separation of sounds, a bit stronger mid-bass punch, less coloring in mids, and more sparkle in treble when compared to R3 Pro.
I covered other comparisons, such as M0 and DX120, in my previous AP80 Pro review, and those will be still applicable to Pro-X, and Pro-X is still superior in sound performance.
Here how Pro-X compares to some of the popular usb dac/amp dongles connected to my Galaxy S22 phone.
AP80 Pro-X vs S22 + Lotoo S2 – close sound performance, just with Pro-X having a little more revealing tonality in mids and a touch more sparkle in treble, while S2 being a little warmer and smoother. S2 has improvement in sound dynamics as well.
AP80 Pro-X vs S22 + L&P W2 – their tonality is not too far off, leaning more toward neutral revealing characteristics. W2 soundstage is a bit wider, and I do hear some improvement in vertical dynamics, but again, not exactly night and day difference.
AP80 Pro-X vs S22 + Cayin RU6 – RU6 does have some improvements in layering and separation of the sounds, as well as improvement in dynamics, but the difference with Pro-X is not exactly night and day. In terms of tonality, they are not too far off either.
The bottom line, these $300 usb dac dongles don’t sound too far off from Pro-X. They will offer some marginal technical improvement and if you are going for a pure audiophile quality performance, they do have an edge over Pro-X. But it’s not night’n’day difference. Plus, there are other advantages, such as Pro-X having a built-in battery so you don’t have to drain phone’s battery, and Pro-X offering MQA 8x. And don’t forget, you can also use Pro-X as a transport to drive these dongles, giving your smartphone a break.
Pro-X is packed with a lot of wired and wireless features I would like to go over based on what I have tested.
To enable the LO from 3.5mm headphone output, you have to select it in settings. It sets the volume output to fixed max level. It’s probably not a true LO, not many DAPs have a true LO when using a shared PO/LO port. But when I tested it with Romi Audio BX2 amp, I found no clipping or distortion. So, if you have some very demanding headphones, you can use Pro-X as a source to drive external amp.
Connected to my Thinkpad T480s (Win10) with a regular usb-c/usb-A cable, I didn’t have to install any drivers, just selected USB Audio in Pro-X settings to enable DAC. Windows recognized the device, setup necessary files automatically, and was correctly displaying bit rate during the playback. The sound listening directly from Pro-X vs my Laptop + Pro-X was nearly the same.
Then, I performed the same test using my Galaxy S22 and Pro-X connected using usb-c OTG interconnect cable. Pro-X was recognized right away, entered DAC mode (indicated on the screen), and I was able to control the volume from Pro-X. The sound from Pro-X directly was identical to listening to S22 + Pro-X.
I tested Bluetooth Tx with various wireless headphones and IEMs and found the connection to be stable and operational in open space 35-50ft away (depending on which headphone/earphone I was using). Also, Bluetooth Rx works fine, converting Pro-X into a wireless dongle connected to different IEMs. Once you enable BT on Pro-X, I was able to search and find the DAP on my S22 phone. It was paired up in seconds, I enabled LDAC audio under the paired-up device name on my smartphone, and off we go. While playing music, Pro-X was connected as Wireless DAC/amp, transmitting audio using LDAC.
USB digital out.
Using Pro-X as a digital transport, I had no problem connecting and testing L&P W2, Lotoo S2, and Cayin RU6 usb dac dongles. With S2, I was also able to confirm the control of the playback and skipping of the tracks remotely from a dongle. When connected, Pro-X had “USB Audio Device connected” message, and I was able to control the volume straight from the dongle. The sound quality with corresponding dongles connected to Pro-X vs S22 was the same.
If you are OK with a local playback and don’t want to be bothered with your smartphone as a transport for your dongle, Pro-X makes a great mini digital source.
In my recent reviews of various USB DAC/amps I mentioned that these dongles became a replacement of entry level DAPs where people use them to turn their smartphone into a DAP. So where does this leave AP80 Pro-X? I think it puts it in a unique position of a “super dongle” with a lot of very useful functionalities. You can use Pro-X as DAC/amp connected to your smartphone, a dongle that has its own battery and will not drain your phone, a dongle that has its own volume and transport/playback controls, a dongle that can give you MQA 8x decoding which come in handy when streaming Tidal on your smartphone. Or you can use Pro-X as a digital transport source to drive other dongles, to give your smartphone a break. Or better yet, you can turn any dongle into wireless by pairing Pro-X with your smartphone through Bluetooth and connecting a dongle to Pro-X, like in the picture below (sorry, came out a bit blurry, but you get the idea):
And don’t forget, you can pair up Pro-X wireless with your smartphone or DAP and connect your wired IEMs/headphones to turn them into “wireless”. While doing that, you will also have access to volume and hw (play/pause/skip) buttons on Pro-X to control smartphone playback remotely. Plus keep in mind, this is still a fully functioning portable mini-DAP running Hiby Music OS with most of the functionality of the full app, including MSEB effects. Its dual ES9219C DACs sound is pretty good, clean, detailed, spacious, and you get both SE and BAL outputs. Pro-X looks great and super compact. And its small footprint is very convenient for taking your music on the go when working or playing outdoors, exercising, biking, etc., while using it either wired or wireless. Possibilities of use for this $189 jack-of-all-trades Hidizs AP80 Pro-X mini-DAP are endless.