I have received the promised evaluation loaner balanced GanQi amp module upgrade kit for the HM-801 in a nice, separate presentation case. I'm calling it a kit, because it includes not only the amp card, but a variety of TRRS adapters, plugs and even a balanced HE-xxx series 3.5mm TRRS replacement cable. I will be able to test that with the pair of HE-300s also received the same day, in fact, the new cable will probably be a welcome improvement over its stock cable.
The following quick iPhone shots show the package, as well as the easy, straightforward installation steps of the module into the GanQi bay of the DAP. Luckily, I also received a custom Eclipse TRRS-terminated 48" OM cable for my JH13 Pros, as shown below.
I will post a review and proper DSLR pictures once the obligatory burn-in has been completed, but the new module worked as advertised, and with the newly released Diana Krall "The Girl In The Other Room" 24/96 high-rez album, its sound was already impressive. The module's gain has been tuned to accommodate full-sized cans such as the HE-300s and 500s as well--which explains the provided cable--yet, I was able to detect no hiss with the JH13 Pros. There has been, however, a very slight overdrive at zero volume level, where I could barely register the current tracks playing softly in the background. This is not an issue at all for me, just noting it for the sake of completeness, at least as far as initial impressions go. Any kind of hiss with sensitive IEMs--as the v1 versions of the ST amp modules had--would have been the worst case scenario for me, since I do most of my portable listening with them, as opposed to full-size or portable cans. But that is not the case at all, and I would wager this won't be
The metal cover perfectly fits in the original's place, and the bump-out TRRS housing--a nice and necessary touch, since modifying the HM-801 chassis would have been a nonstarter for many obvious reasons--has been manufactured precisely to accommodate the new balanced output capability. There was no need to refer to the included installation manual at all, the process should be wholly intuitive to any existing HM-801 owners who previously replaced the standard amp module in their devices.
More impressions will be posted later, once I had a chance to complete the burn-in process. I admit I've been neglecting the HM-801 recently due to my other audio adventures, however, the new amp module has definitely rekindled my interest to find out just how far the platform has advanced with this long awaited, new feature. As you could tell, I'm a big fan of balanced headphones and systems even in the portable form factor. The balanced HM-801 should be an interesting listening experience, especially those who own HifiMAN HE series headphones, such as the HE-500s, which respond well to balanced, high-quality amplification from a high-resolution source, especially in the aspects of instrument separation and sound stage enhancements.