Edit: I forgot to mention the power supply. Added.
I did! Sorry I haven't responded yet, I've been too busy listening.
I don't have an Audiophile vocabulary, I'm sure there are better terms for what I'm trying to describe, so please forgive my long form descriptions of things. My gear description is at the bottom of this post.
First impressions:
- Sound quality: These are, as one would expect, a phenominal step up from my previous daily listeners, MB-Quart Quart Phone 400 (today these are known as German Maestro GMP 400 (http://www.german-maestro.de/US/gmp400.htm)). The sound is just uncolored. I don't hear any spikes or dips at any frequency. And certain tracks demonstrate how INCREDIBLY low these things go; so far, the best demo I've found is the opening of Beats Antique's newest album A Thousand Faces, the song Overture at about 0:42 there's a bass drop that goes about as low as I can hear without any noticible peaks or dips. Friends who primarily listen to this track on subwoofers say the note goes down low enough to the point where you feel but cannot hear it. Obviously, you're not going to "feel" a note like that coming from headphones (doesn't affect my respatory system, at least not yet), but it's pretty clear that they aren't lying about the 7Hz end of the frequency response curve.
These are as transparent a headphone I have ever listened to. I can't point to any one part of the sound and say "Oh, that's the phones." It's as close as I can image to plugging a signal straight into my brain as I could imagine. I can hear Norah Jones taking a breath before she starts singing. I can hear picking noise on certain guitar tracks. It's amazing what's there now that didn't used to be.
The sound stage isn't as good as I expected it to be. I'm not sure if that's because of the music I'm listening to, because these are only 207s and not 507s or Sigmas or whatever, or if I just don't know what I'm talking about. But I expected to be able to close my eyes and picture the instruments in the room and be able to "point" to them. So far, I haven't found a track on which I can do that. I'd love recommendations for well recorded tracks that have good spacial imaging.
- Comfort: They're a little heavy. Not surprising, it's like I have a couple aluminum paperback novels strapped to my head, and it causes a bit of neck tension after a whole day of listening.
The ear-speakers (cans? But they're square! Boxes?) swivle up and down to lay flat on the head, but they have a stop at the top that prevents them from going too far top-in on the head. Unfortuately, the way my head is shaped, this causes the tension to be greater at the bottom than at the top; they push into my jaw a bit and it's uncomfortable. I've seriously considered removing that stop and just letting them rest naturally on my head. Anyone have any suggestions about this?
- Amp: I haven't done anything to the amp yet, but I am interested in reviewing the proposed modifications to the SRM-252S to see what makes sense to me. I'm a DIYer (see my gear description below), so I'm not afraid of a soldering iron and am happy to replace components if it makes sense. Having said that, I haven't found anything that really screams to me "This little thing sucks, you should replace that component to fix it." Hence, "makes sense" in my previous sentences. I don't want to mod just for mod's sake.
I am very interested in trying these cans-- err, boxes on a direct coupled transformerless ES tube amp. I don't have one (anyone in or around San Luis Obispo, California have an amp I could borrow?) so I have on my project list to build one. It's pretty low on the list right now, but it is on the list.
- Power: I connected the Japanese 100vAC to 12vDC wall-wart up and measured the output. Without a load, it was putting out 20vDC. I'm not sure how that would have dropped with a load, but I wasn't willing to try it and find out. So I took a 12vDC 1A switching wall-wart from an Ethernet Switch with an input range of 100-240vAC (what I had laying around), cut the cord and reversed the polarity (works with amps as well as warp cores!) and it works like a champ. I haven't heard any noise from the switcher, but it may just be below the threshold of my tinnitus. One of these days, I may get around to finding/making a clean regulated 12vDC supply, but I don't feel the need for it right now.
Listening Rig: It's nothing specatular right now, but here's what I've got:
- Mixer/Pre Amp: I designed my own mixer and headphone amp several years ago. It takes three analog stereo inputs, mixes them, then outputs the result through a pair of LM6321 current buffers. It's very similar to a PiMETAv2 (http://tangentsoft.net/audio/pimeta2/) but with the op-amp in inverting mode so I can use it as a mixer, and with true dual-rail supplies so I don't have a ground channel. Otherwise, I'm still using the Jung Multiloop feedback system with the LM6321s. Since this is feeding the SRM-252S, it's not pulling enough current to need the LM6321s, but they're there.
- Source 1: grubDAC (http://diyforums.org/GrubDAC/GrubDACoverview.php) that I built myself. It only does 48kHz/16, but that's ok, most of my music is CD ripped to FLAC. It is DC coupled, which is very nice. (So is my mixer/amp above.) The grubDAC is connected to my work desktop. I use Banshee in Ubuntu for music playback. I also use Spotify and Amazon Cloud Player, but this week I've been concentrating on quality so local playback of FLACs (which neither Spotify nor Amazon Cloud Player support) it is.
- Source 2: An analog cable to my laptop. This spends most of it's time with the volume turned down. It's there so I can use VoIP or watch YouTube videos or whatever on my laptop without having to move cables or swap headphones (the original purpose for the mixer in the first place.)
- Source 3: An analog cable to my iPhone. Also spends most of its time with the volume down. But I do have several more albums in ALAC on my phone. The UI is such that I prefer Banshee on my desktop computer to it most of the time.
The output of my mixer/amp goes to the input of the SRM-252S and thence to my phones.
So far, from the limited selection of music I have ripped on my work computer, the "Killer App" CDs are (in no particular order):
- Beats Antique, "A Thousdand Faces"
- Norah Jones, "Not Too Late."
- Nine Inch Nails, "Hesitation Marks" Audiophile mix.
- Device, "Device"
- Emika, a song called "Drop The Other" loaded by a friend who wanted to test it on my phones. I need to get the rest of this album...
- Howard Shore, "The Hobbit (Soundtrack)" (I also have the LoTR soundtracks, but in ~200kbps MP3. I've lost the CDs and can't re-rip them. Maybe it's selection bias, but I haven't listened to these very much.)
- Jethro Tull, "Aqualung (20th Anniversary)"
Over all impressions: Holy crap, I love these phones. I was worried that I'd regret spending the money, but I don't.
What's this slope I'm standing on? It's a little slippWHOA!!!! *falls on ass and slides down toward spending more money* Looking for a better USB DAC. Any suggestions for something in the $100 to $200 range? Kits are good (preferred, actually). Preferably something that will reliably do 96/24 or better, "just cuz.."
