A few weeks ago @CEE TEE asked me if I was interested from anything in the Apos Audio catalog. A tube amp? Hmm, maybe not, well maybe that DarkVoice 336SE? Pass, I'm in SoCal which is swimming with DNA, EC, and ECP headamps, not to mention @Zampotech's stuff is just around the corner if I wanted to go budget. Topping A90? Sigh, another zero point zero zero zero zero type design. Uses the BB TPA chip. Hmm, at least it will sound different from the compressed square of the 789, THX, AHB2, 389, HP4 (thank you @dubharmonic for the visual analogy), but not sure what a slightly less expensive Sennheiser HDVA600 with lower output Z will do for me. Well at least it does offer under x1 gain for IEMs. Bah, pass, I'd rather deal with channel imbalance than an amp that imparts its sound so strongly that there's do difference between an iPhone or Wavedream as the source. So I got to thinking: Something that works with IEMs. That's what I need. I had a conversation with a member a while back regarding an small amp that would work well with hybrid DD/BA IEMs, namely the Solaris (OG or 2020). I've always ran CFA IEMs from the Sony ZX2 ever since I've picked it up. The reason is that the ZX2's organic sound, it's organic lows, mids, and highs, meshed really well with the OG Andromeda. I added the OG Solaris to the mix and it worked well enough. However, it wasn't as perfect as I wanted to be. While the organic highs of the Sony ZX2 player does wonders with the CFA BA drivers, the DD drivers, with their physicality, slower decay, and softer attacks, didn't gel so with with the ZX2. It wasn't bad, but it could be better. Similar issue with the Drop JVC FDX1. It's upper midrange emphasis is tamed by the ZX2, but it's bass really needed some help. So ahead I forged on the Apos website. Wait, what's this xDuoo boopy doop thingy? Hmm, the Force or Magic Eight Ball is telling me something here. "Hey, @CEE TEE, can you get me the iDuo duodenum X15 ZYX +++ mega version edition doodad?" "Sure thing" @CEE TEE replied. Well it turned out my hunch was right. The subjective portion of this review will largely be based on my use with the Campfire Audio Solaris 2020. I am also assuming that the CFA Ara will work well. It's suddenly occurred to me that more reviews should emphasize synergies with gear. Heck, Craig at Eddie Current has always said "I wish these assholes would stop complaining and get the headphone that works best with the amp or the amp that works best with the headphone". Right, headphone and headamp must be thought as one. Can someone advise the manufacturers to come up with a better name than xDuoo? It sounds like a dog ate something and left it on my front yard. Also XD-05 Plus is dumb. Dozens of people already have it confused with the non-Plus version. Also XD-05 sounds like something Elon Musk will name his next child. I suggest renaming the brand to Wolf. And this gimzo Warrior. Thus the product can be referred to by Americans as the Wolf Warrior. Or maybe Abbott and Cornelius. The "AC Five" sounds quite swell. Anyway, the xDuoo XD-05 Plus is Chi-Fi at its best. Extremely affordable, plain and unassuming (like the great Chinese leader Deng XiaoPing who laid the foundation for a greater society so millions of Chinese would no longer to have to eat tree bark soup), damn good sounding based on tried and true design, and opamp rollable (of course!). Do you guys remember the much heralded Leckerton UHA-6Smk2, well this is the next coming of it, except the DAC doesn't suck like on the Leckerton and it works straight away without a hitch with my Pixel 2 XL phone via USB C. There are a few niggles, but none of them were showstoppers, at least not to me.