FiiO - LC-78A

I hate it when manufacturers make things harder than it has to be for customers and 2-pin, MMCX, QDC connectors are exactly that. I got the Fiio UTWS5 with the MMCX connectors a while back to use with 7Hz Timeless but I haven't been able to use them with anything else because all my other IEMs are 2-pin or QDC (don't get me started on that crap).

I've been waiting on these for months and snatched them when they were finally in stock. Thank you to Headphone Zone for making that possible.

Now coming to the MMCX to 2-Pin adapter, it's very clear that Fiio made these to ONLY work well with their own IEMs and nothing else. I hate when manufacturers do this, it really grinds my gears. The base of the adapter has a circular extrusion so out of the box, you can forget trying to use these with any IEM that has a 0.78mm 2-pin connector (which is pretty much every IEM that use 2-pin - i.e. Truthear Hexa, Moondrop Aria, Chu II, Blessing 2, etc)

I worked around this by heating up a SIM ejector tool and shaving off the sides of the circular plastic extrusion to make it more rectangular. I've added images so you can marvel at my work. With this 'mod', I'm able to use it with my IEMs that expect 0.78mm 2-pin connectors but it is still not a snug fit and my Hexas and Arias fall off easily with the slightest of nudges. It works alright but is very finicky and a bit risky, especially if you like to listen to music while on the can. The IEMs that expect QDC connectors (like KZ, QKZ HBB, etc) seem to work alright though and are an okay fit.

Anyway, I've given up now. I'm not going to try and find other ways to use my IEMs with the UTWS5. In an ideal world, all these silly connector/adapter thingies would've been bundled in the box by Fiio with your UTWS5 purchase but it seems every company in the audiophile space like to nickel and dime their customers. At least Fiio is selling these for 599 INR and not 1990 INR like the fine people at OEAudio.

All things considered, if you own the UTWS5 with MMCX connectors and want to try using 2-pin IEMs with it, you should get this and hack away at it to make it work. You'll only lose 599 INR trying.

BTW depending on the IEM, with this adapter on, you may not be able to close the UTWS5 lid completely. I have to push down on mine to get it to close when using these with the Truthear Hexa.

0.78mm Pin connected to MMCX perfectly

After all the things put together, i. e. Fiio fh1s with .78mm input port, this pair of converter and tripowin upgrade cable the whole thing become really clumsy and looks like a bit vulnerable too. As far sound quality is concerned it does the job perfectly. Go for it if you need to insert a mmcx cable to your .78mm iem.

Good, does the work pretty well. Initially the connection feels very tight and as these are very tiny can be bit tricky to pull out of the iem. However, a connector detachment pin comes in the package.