Nice to see that the ES10 is finally getting some love here on head-fi. I've owned them for almost four and a half years now and never even once thought about selling them. I think that says allot.
It definitely needs an amp to shine IMO. But for people who want this great headphone to sound even better and open up even more, I would definitely recommend a cable upgrade. The ES10 has very large full sized headphone drivers that are paired with a very thin cable. This I believe leaves the driver not being able to perform to it's fullest potential. The original cable also has a little bit to much resistance. Upgrading this to a thicker lower resistance cable will definitely tighten everything up and widen the soundstage. You'll still have that great sounding bass but it is more airy and tighter which I like for this headphone. Definitely more detail and wider soundstage with details popping out from a sense of direction which makes it very enjoyable to listen to. The cable upgrade is a huge improvement for the ES10. You have some headphones that will benefit a little from cable upgrades and some that it has a huge effect on and almost makes it sound like you're listening to another headphone altogether. With the ES10 leaning towards the latter.
I personally used a cable intended for digital audio (AES/EBU) but came highly recommended as a good microphone cable. From what I understand microphone cables make excellent headphone cables as well. And having tried a couple of different mic cables I ended up with a pretty thick cable but it was the best sounding one IMO (I originally wanted a thinner cable).
Here are some pictures of the ES10 with the cable upgrade. I went with white shrink tubing and cable sock because I thought it looked really sexy on the ES10 with the titanium earcups :p.
Edited by zool - 5/20/14 at 8:04am