I put 14 more days of burn-in into the AMP3 and now have over 610 hours on the AMP3 (the 275 plus another 336 or so). I have NOT listened to the AMP3 since the last time I reported on it here. I have to admit that when I plugged in the ES3X tonight to listen for the first time in 2 weeks, I was not looking forward to it and was expecting the same forward bright sound that I've come to expect from it. Well, the AMP3 DAP/Amp sound signature changed as much in 600 hours of burn-in as my RSA Predator, which I also didn't like out of the box and barely at 300 hours. Both amps have set a record for longest burn-in (besides my Woo WA6 and ALO Amphora with Vcaps and Blackgates).
This does NOT sound like the same DAP/amp I heard two weeks ago. It is now useable with all three IEM in terms of sound signature, and the sound quality is probably closer to that of the Meier Headsix now instead of worse than the Nuforce Icon Mobile. I think I will pull that amp out later to compare the two. Before, with only 275 hours or less, the UE11Pro were the only ones out of the three that were useable with the AMP3 because of the frequency response, and even then it was not very smooth or refined sounding. But that has now changed. When HiFlight recommended 600 hours he wasn't kidding.
Other than the hiss with ES3X, which is still far too much (but much better with JH13Pro and UE11Pro), the AMP3 sounds very nice with ES3X now! Gone is the sibilance with Eva Cassidy, Kate Ceberano, and Diana Krall. The too forward nature is also improved and it sounds more open and transparent. This is a huge change, nothing subtle about it. If not for the hiss with the ES3X I could live with this sound. A Westone volume attenuator helps cut the low volume hiss by reducing the sensitivity, but with IEM a very detailed IEM like this I somehow feel like I am missing a little something when I use it.
Switching to the UE11Pro proves that the AMP3 is still a good choice for those IEM - with better tighter bass control without excess or lack, non-recessed mids, and no more sibilance although there is a nice shimmery sparkle to the treble which is not too bright. The UE11Pro have much less hiss with the AMP3, and a volume attenuator is not mandatory to kill the amount that gets through. Out of the three IEM I still feel the UE11Pro are the best ones to use with the AMP3.
The JH13Pro sound better than before as well, with hiss that like the UE11Pro is still well below that of the ES3X. The only odd thing is that the AMP3 brings the JH13Pro bass impact down to the level of the ES3X now, with a little more sparkle in the highs vs the ES3X. I still would not say it is too bright anymore.
So there you have it - two weeks ago I was ready to sell the AMP3 if it didn't improve, and today I don't think I will do that now. It's now a viable option for listening to any of the three flagship custom IEM (although you may need a volume attenuator for hiss). Plus it looks very rugged and and could make a decent "toss about" MP3 player and amp. The AMP3 also does very well with portable over the ear headphones like SR-60, HD-25-1 and Nuforce UF-30.
JH13 plugged into the AMP3
First the sound. The details of the imaging in space are sculpted as if vivid crisp sounds of a Myriad of locations each distinct and clear sprinkled spherically in a rain of music to delight the soul in perfection not hitherto heard, every tincle every bass every mid they all pour out seamlessly. Not like I was there in real space but as if transported to a pure music space where there are only expectations of surprise and the fulfillment or the dispersed instruments dancing from a sphere of locations creating the experience that makes me fulfilled. Finally there is what I want to ask.... What took everyone so long to find this combination? I am in satisfaction heaven and I want to say no more.... can you sense my enthusiasm?!!!!
A tad of brightness?? debating with my ears, that I am glad to hear has evened out with time, but I am delighted nevertheless.