Though I don't have the top amps at my disposal, I will say that even from the formidable graham slee voyager, or more powerful travagan's red, the jh13Pro induces a lot of distortion at the amp level. I would imagine that even more powerful amps may do better, but have a doubt that they will be that much more controlled when driving the jh13Pro. In fact, while the iem may be able to scale up much higher, it is likely held back because headphone amps aren't able to perform well enough.
it seems at intervals which may represent crossover networks. I am sure that an amp which can drive the JH13Pro at amp levels to 0 dbl across all frequencies and maintain a good stereo separation (none of which I am convinced is possible with conventional headphone amps) will make the iem sound even better, but no one can experience that yet.
it might be a project for amp builders. Not only to make an amp which drives dynamic headphones to 0 dbl, low distortion, and good separation, but an amp which can do the same for multi-balanced armatures.
if the JH13Pro have this problem imprinted on amps, i can only imagine what the Fit Ear 668 (6 voice cross over 6 units, 8 receivers) does!
This link refers to a review of the Fireye II amd/DAC, but every amp I have tested, whether mains or battery powered, has suffered the same frequency response when driving the jh13Pro. Suffice to say that when something can properly drive the JH13Pro, be prepared to hear a completely different iem. Again, for reference only I included only the Fireye II. All amps perform reasonably within the same bounds. The RMAA shots are about halfway down the review.
Do they fit? Do you like them?
