[satwilson]

  I've spent some time with the battery pack attached, using regular C cells, not rechargeables. I don't hear any difference, comparing the same track heard with the battery pack and the OEM transformer. Granted, this is me making the change between tracks. I really should have my son or someone else change the tracks, and then switch places, so we at least have single blind trials, since I'm not sure double blind would be possible. But I don't hear a difference after about a half dozen comparisons.

I didn't hear a significant difference with the battery pack, others have reported better sound. I still believe I hear much better sound with my 3a supply. Could some one with the proper test gear measure the current draw of the E90 playing music hooked up to a 3-5a supply? This might shed some light on this situation.

 

[satwilson]

  I have a ES 950 system on the way and have been following this thread. One person discussed feeding the E/90 energizer from the "variable" output of his DAC/Headphone AMP.
 
I am curious if this could be harmful to the E/90 energizer? I intend to eventually get a decent Stax amp to use with the Koss cans (it's shipping with an extension cable modified with the Stax connector at one end).
 
But in the meantime, I'm going to try some of the hacks/mods I've found in this thread (the 3rd party power adapter, etc.) but also was wondering if it would be damaging to use my dynamic headphone amp (a Ray Sam Raptor as a sort of "pre amp") and possibly as a way to add a bit more "heft" to the sound.
 
So is this ill advised? I've read that it is possibly damaging to Stax amps to use "variable" outputs with their energizers and would just assume that the same principles would apply to the E/90??
 
Thanks for any information...
 
.joel

I use that setup based on some advice in one of the other 950 threads, Koss ESP/950, a fine electrostatic headphone . It is buried in there somewhere, it has also been mentioned the E90 can accept up to 5v input I believe early on in this thread. The line out on my AGD NFB12 is 2v and the variable ranges from 2-5v. Lineouts from various units do vary in voltage. I estimate based on the position of the pot I am at about 3-3.5v for comfortable volume in my setup. Perhaps Kevin Gilmore or someone with the schematic can comment on this. I have not had any problems and for me this made a big difference in the sound.

 

[Kokomo O]

Satwilson, how would you characterize the improvement you hear with the 3A power supply?
 
Edit: I know earlier you said it gave you a more detailed presentation and better bass. Can you flesh that out a bit, give us a bit more information about the detail and the improvement in the low end? Thanks in advance.

 

[satwilson]

  Satwilson, how would you characterize the improvement you hear with the 3A power supply?
 
Edit: I know earlier you said it gave you a more detailed presentation and better bass. Can you flesh that out a bit, give us a bit more information about the detail and the improvement in the low end? Thanks in advance.

My subjective opinion, overall the sound is somewhat warmer or lush, as before more dry or analytical. Treble detail still there, cymbals just sound more realistic. The bass has more slam and presence. To me like listening to speakers when you go from an underpowered amp driving them, upgrading to a properly matched amp with more power that makes the sound open up. My other headphone is the T50RP, modded to BMF spec, that always has better bass slam and quantity. The bigger power supply brings the 950's more in that direction. Hope this helps.

 

[Kokomo O]

Thank you--think I'll give it a try. If it give a real improvement, it's a cheap one.

 

[s1rrah]

 
My subjective opinion, overall the sound is somewhat warmer or lush, as before more dry or analytical. Treble detail still there, cymbals just sound more realistic. The bass has more slam and presence. To me like listening to speakers when you go from an underpowered amp driving them, upgrading to a properly matched amp with more power that makes the sound open up. My other headphone is the T50RP, modded to BMF spec, that always has better bass slam and quantity. The bigger power supply brings the 950's more in that direction. Hope this helps.

 
This is why I read forums.

 

[dukeskd]

ESP950 available for $599.99 with coupon code "CM40" at Koss.com

 

[coolchillies]

Yesterday it was $750. Only US and Canada though. I hate where I live 

 
I'm guessing this could be against forum rules, but is some good soul prepared to buy one on my behalf?

 

[s1rrah]

I just payed 760 for one off of Ebay last week; LOL ... wish I'd waited now and just got one brand new off of Koss.com for a hell of a lot less.
 
Oh well ... the lifetime warranty sort of makes it a moot point on the chance any thing is wrong with the used kit... but still, would rather have bought new.
 
600 bucks. Killer price ....

 

[nick n]

  Yesterday it was $750. Only US and Canada though. I hate where I live 

 
I'm guessing this could be against forum rules, but is some good soul prepared to buy one on my behalf?

they  ship internationally the info is on the site.
 
"PLEASE NOTE:
Koss ships products directly to addresses in the U.S. and Canada. In addition, we now ship products worldwide through our trusted partner, Bongo International"

 

[shipsupt]

The ship internationally, but last time I checked they do not honor the 40% discount code on international orders.  
 
Hopefully this has changed... but not likely.

 

[s1rrah]

Got my ESP-950 kit today and upon very first listen there was a completely not right, very obvious distortion in the left channel; tested the kit with front and then back inputs and three different sources.
 
Right channel sounds excellent but the left channel is whacked, real bad, LF distortion that gets worse the louder the volume is pushed.
 
Needless to say, on the first day of having the kit, I've already sent it off to Koss for replacment. Guess it's a gamble, really ...
 
Gives me more time to find an affordable Stax amp to use with the Koss headphones; I want to get a good E/90 and just put it on a shelf as back up....
 

 

[goldenSHK]

Oh Jesus I am trying vehemently to fight off the urge to purchase this with the $400 off from Koss today. I just bought a set of Denons recently, and can't justify this so soon. I realize this may be the worst possible thread to ask, but can anyone dissuade me from burning my bank account? Is this an annual thing, so that at worst I can wait until next year for this or is this literally the lowest new sets of Koss ESP950 have ever gone? I have heard 40% off isn't such a unique thing from Koss. 

 

[Za Warudo]

I wonder if I can cancel my HE-400 order (not yet sent out for delivery) and buy this instead.  If you factor in the cost of an amp/dac for the HE-400 it wouldn't be far off from the ESP-900 system.  My major concern is the quality control issues.  If shipping for return/fixes were free then it's a no brainer.

 

[Gary in MD]

  Oh Jesus I am trying vehemently to fight off the urge to purchase this with the $400 off from Koss today. I just bought a set of Denons recently, and can't justify this so soon. I realize this may be the worst possible thread to ask, but can anyone dissuade me from burning my bank account? Is this an annual thing, so that at worst I can wait until next year for this or is this literally the lowest new sets of Koss ESP950 have ever gone? I have heard 40% off isn't such a unique thing from Koss. 

This is the 3rd year that I've seen them come down to ~$600 around the holidays, either at Koss or Amazon.  Nobody can guarantee you anything, but chances are good they will do so again.