I've had my ESP-950's for almost a week now, and I thought I'd share my first impressions.
I ordered mine directly from Koss during their 40% off Cyber Monday sale. I had wanted to try a pair of electrostatic headphones after reading about their alleged virtues, and also as a longtime owner of many pairs of Magneplanar Loudspeakers. Magneplanars are NOT electrostatic but planar magnetic, yet both designs have similar sonic characteristics. In any case, I love the natural sound from these designs, and was hoping that electrostatic headphones would have a similar sound signature.
I own a number of mid-level dynamic headphones from Grado, Audio-Technica, Etymotic, and AKG. I've used AKG-K702s as my main headphones for several months now, driven by a Schiit Lyr 2 amp. I've been pretty happy with these headphones, but I was never able to get the same level of magic from them that I've gotten from any of my Magneplanars. So I started reading this Koss ESP thread a couple of months ago and some of the entry level Stax threads.
I really wanted to start with the Koss system for a couple of different reasons. The lifetime warranty, and the system also came with an amp. But I wasn't going to pay $1000 when you can get into a basic Stax system for $700-$800, and many consider it a better system. I've had more than one person mention that the Koss ESP's with an upgraded amp (Stax, KGSS, BHSE, etc) could offer world class sound, so I figured this would likely be the upgrade path I'd take.
I unbox my ESP-950 system and the first thing I notice is that everything smells like Grandmas attic. Not really bad, but it was kinda musty. Then it occurred to me that these may have been sitting in the Koss warehouse for 20 years. The other tip was that it said made in the USA on the box. This is a good thing but it wouldn't be a shock to me if Koss confessed they hadn't had a new run of these for a very long time.
They come in a leather bag that looks like something you'd keep your SLR camera and a couple of lenses in. It's a nice touch but pretty worthless to me. The auxiliary battery pack to run the amp was probably a good idea 20 years ago, but not very practical. These headphones are light, but not exactly what I would consider portable. So the battery case, the included cables, and the storage bag all went back into the box and will probably go into storage, never to be seen again unless a repair is needed and I need the box again.
Others have mentioned the Koss energizer box is pretty cheesy. Yeah it kinda is. The RCA connections on the back are recessed, so good luck trying to connect boutique cables with large RCA plugs. I used a pair of SignalCable Silver Resolutions, and they barely fit in. Not a big deal, but this could be an issue for some people. The dual volume control wasn't a big issue either except you have to be careful to turn them up together else you lose where middle really is with the balance. I found myself adjusting one channel up slightly higher than the other. I'm not sure if it was because the two volume pots don't track identically, or for some reason I thought it sounded more correct to run the left side a little higher than the right. Who knows. There's no reference or way to tell.
Assuming these “earspeakers” need some time to break in the diaphragm, I probably have about 30 hours of run time on them so far, but less than 5 hours of actual listening. They seem to get a little better each time I listen. Whether that's real or imagined, you draw your own conclusions. My AKG-702s sounded like crap until I put probably 50 hours on them and then gradually got better up until 200 or 300 hrs. The Koss ESPs look cheap. Not terribly so, but they don't look like headphones that retail for $1000. I'm not too concerned because I'm not trying to impress anyone, but this could be be an issue for some people. I haven't held a pair of Stax for almost 30 yrs, so I don't have any way to compare if the comparably priced Stax look cheap or not. I'm guessing not, the upscale Japanese audio market tends to be kinda picky.
So finally the sound. Most of my listening has come in half to 1 hr sessions at a time....and why I think the break-in effect on these are real. The last couple of times I've listened to these I've come to appreciate the lack of coloration. The sound is really well balanced, and I would definitely choose these over my AKGs to mix a recording. It's just so much easier to isolate components of the music without them getting buried in the mix, like can happen with a more colored headphone. What really gets me is how really low level details are able to pop up through the mix. Not over exagerated or anything, but you just can finally hear them. This is something that my Magneplanar speakers do with the right source and amplification. I think so far what I had hoped to achieve by owning an electrostatic headphone has been successful. I can only imagine that they should get better with a little more time on them. Provided I don't detect any major handicaps with the Koss, I think I may be putting my AKG's up for sale in the future.
Side note - I also just realized how different my Mac music player apps sound. iTunes is now almost unlistenable. Fidelia is significantly better, and Audirvana is better yet. I could hear the differences before with other headphones but now it's night and day.
