Well......... Crap! I'm sitting here wasting a bit of time at work in an empty office (weekend). I've switched back and forth from my shiny new iPhone 5S to the HIFI-M8 (with the same 5S as the source), with my ciems, the 1964 Ears Quads that were their TOL a couple of years ago.
Note - simple attempt to volume match by ear, no blind test. Just a simple switch back and forth to hear what I hear.
I have been claiming that really, the HIFI-M8 (or any amp other than something like the Pico Slim) is just plain overkill for iems/ciems. I've been claiming that straight out of the iPhone was just fine, in fact really good.
* Straight out of an iPhone IS really good, by the way *
The HIFI-M8 has that bit of hiss that we sometimes get out of high-ish gain amps with very low impedance/high sensitivity iems/ciems. But Oh My Goodness! a few minutes with each set up really shows how much better the HIFI-M8 is. On the go you won't hear it, but for idle listening/critical listening - how do I explain it best -
When you look at a stream or tide pool with sunglasses on, you sort of see into the water, but the glare kind of obstructs things. Then you put on a pair of polarized sunglasses and you can see INTO the water, see the fish, the coral, the sandy or rock bottom because the glare is eliminated.
The HIFI-M8 is the polarized glasses. The dynamics are greater, there is a depth and texture to the music that is just not there with the iPhone alone. Bass drums, bass notes on an organ or synth or bass guitar have a palpable feel. The details and quieter little treasures within the music are revealed more fully. Loreena Mckennett's voice soars, and dives and envelops, creeping into one's very soul. Without the M8, still the goosebumps, but not the depth and emotion.
Kinda like watching your kids on a roller coaster - the noise, the screams, it's exciting as hell. Then one of the little sadists actually talks you into getting ON the roller coaster with her - something you haven't done since your honeymoon, and hadn't done for 15 years before that. Clack, clack, clack, pause....... click - HOLY SHIIIIIIIIIIIITE!!!!!
It's kinda like that. OK, maybe a bit (quite a bit...) of way over the top hyperbole, but a very noticeable difference.
If I was an iems most of the time guy, I'd invest in the gain reduction mod. I'm not, so I won't, but I will start using the HIFI-M8 a bit more often with my quads - it is pretty killer!
EDIT - to add a plug for Loreena McKennett. If you are not familiar - check her out. Elemental, The Book of Secrets and An Ancient Muse are probably my favorite albums. Modern Celtic to new age. She has a wonderful, powerful voice, a big range. A profound ability to induce goosebumps. Great stuff, if it falls into your taste range.
Edited by aamefford - 11/16/13 at 10:08am