[Bullseye]

^Hmm didn't know about that. But I think I felt the 950 had more punch with the E/90 than with the 252. However if you say it can be EQd then by EQing the source you can get the same response. The reason why I am amping them with the 252 is because I don't get hum/hiss when doing so, whilst the E/90 due to the power adapter used (w/o ground connection) adds up some hum. Not annoying when music is played, though.

 

[mobbaddict]

This EQ thing is not 100% sure but i found a post from HeadphoneAddict explaining it
http://www.head-fi.org/forums/4882097-post15.html
Ergo uses the same trick with its amps so it's very likely.

 

[niko-time]

Thanks for the information, I think as I am already very happy with them there is no point spending more money which I should really instead spend on food...

 

[ericj]

Quote:

Originally Posted by mobbaddict /img/forum/go_quote.gif Thanks for the answer Bullseye. The E90 might be equalized to add some bass just like the HEV70 paired with the HE60 (from what i read).

As i understand it the thing about the E/90 isn't that it's not powerful, it's that it's unrefined.

The ESP/950 has plenty of bass with the exstata DIY amps, which have no EQ of any kind (and while as yet unmeasured likely has a totally flat frequency response).

Also, the SRM-252 is designed to run lambdas, which have a smaller driver than the ESP950.

 

[Bullseye]

Upss, I remembered I was not using the 252 but the 323. In any case I could not find any noticeable difference in the very short and not controlled test I did between the 252 and the 323. The big pro I found using the latter was that I do not get any HUM.

 

[ericj]

You know, if your e/90 is humming, Koss will fix or replace it.

Given the crap storm that Koss is in right now, i'd say if you have a koss item that needs repair, you better exercise the warranty sooner rather than later.

 

[Bullseye]

The driver unit is not humming, it is the power unit, that does not have ground connection and when connected to the source (without ground) you can hear the ground loop aka hum.

Plus the unit recently came back from guarantee.

Oh and I have to say that I am really really enjoying this cans. Even more than the SR-202. I believe it is because they are lightweight, comfortable and extremely analytical. Plus having a pair without any squeal is great!

 

[AudioCats]

with Pro4AA head band, a bit heavier, but feels more "secure" (the ESP950 band tend to slide on my head....I guess sometime adding a little weight is a good thing)

Pro4 Headband modification (drill and dremel, easy).

 

[praer4life]

so after reading, joining and ignoring the swearing" I came to conclusions that I will go for a set of koss esp 950 electrostatic headphones. as I can get them new for 500.00 next will be the stax cover and stand and there cable for the top headphones they do to rewire. realising after being tired that we are looking at positive/negative x2 each plus 2 earths joint hence 5 pins. if its a six pin then all six cables are separate. as for the inside of the earspeakers once brought and run in for 500 hours, I will know the real sound and based on this I will see if I need to upgrade some of the parts as in membranes to better performance. if I do I would use parts from the omega range. yes if we spend a grand stax are the best simple but at the price I am getting the koss for and a little effort I believe these are hard to beat. driver heads are a different sound so its all personal choice. I think the last thing to mention would actually be my question within this link. once rewired then which energizer can these phones be used with in the stax range? I have also one more thing I may do and go for ariston silver headphone cables just released, as I intend to keep my units for good. so any positive thoughts on the energiser unit to run them let me know Jesus bless you all raju



ps: I have made a word document with every single bit of info I have come across on the subject of making the koss esp950 if you would like a copy email me on this thread with the email i can send you the doc to for free I don't mind.

 

[rsa777]

Where can I get a ESP-950 to Stax adapter? I've search all over but can't come up with anything. Thanks.

 

[grawk]

you can either make one, or I think apuresound will make you one. Or just recable the koss with a stax cable.

 

[450]

So... I'm considering getting an ESP950, because it seems like it would be cheaper than an HD600 and a good amp. Does anyone have a good comparison between the two?

 

[ericj]

fwiw, if anyone else out there actually uses the E/90 on battery power, i've successfully hooked mine up to a slim and lightweight lithium pack.
 
In this case, a "Zap Portable Energy" model D14. The charger is 8.4vdc and it's unregulated output is marked "DC 7.4v" "DC 7v-11v devices only" so i presume it is a 2-cell pack. Claimed 4000mAh.
 
It turns out to be marginal. It does work, I'm listening to it right now, but the power LED flashes red twice a second.
 
I don't hear any audible difference from using the alkaline pack, but it appears that maybe a 3-cell pack would work a bit better. The Zap kit was just attractive because it's cheap and comes with charger & various other accessories. It recharges a DAP or cell phone from it's 5v outlet in a hurry, but I'll have to see how long it can acceptably drive the E/90. And see about finding a similar product in a 3-cell configuration.

 

[Reticuli2]

Questions...
 
There supposed to be a manual or spec sheet in the box with these?
 
Is the front 3.5mm jack considered pretty crappy?
 
And does it take a while to warm up and the channel balance to even out or is the pot on the front got separate controls for right and left because the amp or drivers often don't match very closely?
 
Oh, and what's the max input on the energizer?  It says 1V rms nominal on the downloaded sheet off Koss.  I would assume it's fine with 2V, right?
 
Any risk in overloading these drivers?  Anyone confirm you can crank the amp to max (before the clip light) and still get low distortion and no damage? 
 
Any risk of damaging components with both inputs connected.

 

[Reticuli2]

[size=10pt]I'm also noticing a ground loop hum or that the "energizer" amp is acting as an antenna with the headphones. I have to ground the unit by touching something metal on it like the 3.5mm jack on front. If there's not an audio source device hooked up, it will reduce but not completely go away. EVEN WITH THE POWER TURNED OFF, THE AC WART DISCONNECTED, NO AUDIO INTERCONNECT TO IT, OR THE BATTERY PACK CONNECTED there is still intermittent slight hum in the right channel that requires grounding. Must be a weird design inside with a lot of circuit path, transistors, and capacitors, or something. I guess I could run a piece of wire from the 3.5mm jack (which unscrews pretty easily) along the cable to my head. I suppose that wouldn't be an electrical risk if I just run off batteries. I also think I may have gotten the squeal people talk about when I unplugged the USB interface it was connected to from the computer. Not sure why it'd do it then, but it made a funny sound on the right earcup. Oink, oink.[/size]