Cayin provided the YB04 free of charge for the purpose of my honest review, for good or ill.
Oh Cayin. You never quit, do you?
I’ve loved every Cayin product I’ve tried. To varying degrees, sure, but the baseline has always been thoroughly positive. Both my ears and my eyes are regularly enamored with their gear. Cayin just seems to get Pinky. So when word reached me they had developed their first in-ear monitor, I simply had to get my hands on it.
The YB04 is a quad-driver balanced armature design. Dual Knowles are setup for the higher frequencies, and dual Sonion for the lower range. The shell is a sturdy CnC machined aluminum. The result is a heavy-duty, high-end piece of audio gear that should last a long time. I’m particularly pleased Cayin went with 2pin connectors instead of the MMCX. I don’t have many MMCX cables and I find them a pain to swap. Making this headphone 2-pin opens up my options in a big way. I have tons of those cables.
For the most part, I approve of the shape and ergonomics. I can get a reliable fit, and the shells don’t protrude out of my ear. However, there is some low-level discomfort after long sessions. I think Cayin can work on smoothing out the design and rounding off any hotspots.
The stock cable is fantastic. One of the best I’ve seen. It’s built with nice thick conductors and cutting edge insulation for extreme suppleness and bend. The only flaw is that it’s terminated for 3.5mm single-ended. It would have been great for Cayin to either provide a second, balanced cable, or make the stock cable balanced, and provide an adapter for single-ended use. Instead, creeps like me are left no alternative than to simply discard this beautiful thing and use a 3rd party option.
I went with the Effect Audio Thor II Plus.
Cayin went all-out on the accessories. That leather case is second to none. So lovely! And protective! They give you twelve pairs of tips, with various sizes and tuning, a lapel clip which broke the first time I used it, and a nozzle-cleaning brush. Honestly, I’ve seen far more expensive IEM’s offer far less.